String tables with names of enum items are always prone to go out of
sync with the enums themselves. Ensure during compile time that the
name table of page flags has the same size as the page flags enum.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The array pageflag_names[] does conversion from page flags into their
corresponding names so that a meaningful representation of the
corresponding page flag can be printed. This mechanism is used while
dumping page frames. However, the array missed PG_compound_lock. So
the PG_compound_lock page flag would be printed as a digital number
instead of a meaningful string.
The patch fixes that and prints "compound_lock" for the PG_compound_lock
page flag.
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When MIGRATE_UNMOVABLE pages are freed from MIGRATE_UNMOVABLE type
pageblock (and some MIGRATE_MOVABLE pages are left in it) waiting until an
allocation takes ownership of the block may take too long. The type of
the pageblock remains unchanged so the pageblock cannot be used as a
migration target during compaction.
Fix it by:
* Adding enum compact_mode (COMPACT_ASYNC_[MOVABLE,UNMOVABLE], and
COMPACT_SYNC) and then converting sync field in struct compact_control
to use it.
* Adding nr_pageblocks_skipped field to struct compact_control and
tracking how many destination pageblocks were of MIGRATE_UNMOVABLE type.
If COMPACT_ASYNC_MOVABLE mode compaction ran fully in
try_to_compact_pages() (COMPACT_COMPLETE) it implies that there is not a
suitable page for allocation. In this case then check how if there were
enough MIGRATE_UNMOVABLE pageblocks to try a second pass in
COMPACT_ASYNC_UNMOVABLE mode.
* Scanning the MIGRATE_UNMOVABLE pageblocks (during COMPACT_SYNC and
COMPACT_ASYNC_UNMOVABLE compaction modes) and building a count based on
finding PageBuddy pages, page_count(page) == 0 or PageLRU pages. If all
pages within the MIGRATE_UNMOVABLE pageblock are in one of those three
sets change the whole pageblock type to MIGRATE_MOVABLE.
My particular test case (on a ARM EXYNOS4 device with 512 MiB, which means
131072 standard 4KiB pages in 'Normal' zone) is to:
- allocate 120000 pages for kernel's usage
- free every second page (60000 pages) of memory just allocated
- allocate and use 60000 pages from user space
- free remaining 60000 pages of kernel memory
(now we have fragmented memory occupied mostly by user space pages)
- try to allocate 100 order-9 (2048 KiB) pages for kernel's usage
The results:
- with compaction disabled I get 11 successful allocations
- with compaction enabled - 14 successful allocations
- with this patch I'm able to get all 100 successful allocations
NOTE: If we can make kswapd aware of order-0 request during compaction, we
can enhance kswapd with changing mode to COMPACT_ASYNC_FULL
(COMPACT_ASYNC_MOVABLE + COMPACT_ASYNC_UNMOVABLE). Please see the
following thread:
http://marc.info/?l=linux-mm&m=133552069417068&w=2
[minchan@kernel.org: minor cleanups]
Cc: Mel Gorman <mgorman@suse.de>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This has always been broken: one version takes an unsigned int and the
other version takes no arguments. This bug was hidden because one
version of set_pageblock_order() was a macro which doesn't evaluate its
argument.
Simplify it all and remove pageblock_default_order() altogether.
Reported-by: rajman mekaco <rajman.mekaco@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Print physical address info in a style consistent with the %pR style used
elsewhere in the kernel. For example:
-Zone PFN ranges:
+Zone ranges:
- DMA32 0x00000010 -> 0x00100000
+ DMA32 [mem 0x00010000-0xffffffff]
- Normal 0x00100000 -> 0x01080000
+ Normal [mem 0x100000000-0x107fffffff]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull CMA and ARM DMA-mapping updates from Marek Szyprowski:
"These patches contain two major updates for DMA mapping subsystem
(mainly for ARM architecture). First one is Contiguous Memory
Allocator (CMA) which makes it possible for device drivers to allocate
big contiguous chunks of memory after the system has booted.
The main difference from the similar frameworks is the fact that CMA
allows to transparently reuse the memory region reserved for the big
chunk allocation as a system memory, so no memory is wasted when no
big chunk is allocated. Once the alloc request is issued, the
framework migrates system pages to create space for the required big
chunk of physically contiguous memory.
For more information one can refer to nice LWN articles:
- 'A reworked contiguous memory allocator':
http://lwn.net/Articles/447405/
- 'CMA and ARM':
http://lwn.net/Articles/450286/
- 'A deep dive into CMA':
http://lwn.net/Articles/486301/
- and the following thread with the patches and links to all previous
versions:
https://lkml.org/lkml/2012/4/3/204
The main client for this new framework is ARM DMA-mapping subsystem.
The second part provides a complete redesign in ARM DMA-mapping
subsystem. The core implementation has been changed to use common
struct dma_map_ops based infrastructure with the recent updates for
new dma attributes merged in v3.4-rc2. This allows to use more than
one implementation of dma-mapping calls and change/select them on the
struct device basis. The first client of this new infractructure is
dmabounce implementation which has been completely cut out of the
core, common code.
The last patch of this redesign update introduces a new, experimental
implementation of dma-mapping calls on top of generic IOMMU framework.
This lets ARM sub-platform to transparently use IOMMU for DMA-mapping
calls if one provides required IOMMU hardware.
For more information please refer to the following thread:
http://www.spinics.net/lists/arm-kernel/msg175729.html
The last patch merges changes from both updates and provides a
resolution for the conflicts which cannot be avoided when patches have
been applied on the same files (mainly arch/arm/mm/dma-mapping.c)."
Acked by Andrew Morton <akpm@linux-foundation.org>:
"Yup, this one please. It's had much work, plenty of review and I
think even Russell is happy with it."
* 'for-linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping: (28 commits)
ARM: dma-mapping: use PMD size for section unmap
cma: fix migration mode
ARM: integrate CMA with DMA-mapping subsystem
X86: integrate CMA with DMA-mapping subsystem
drivers: add Contiguous Memory Allocator
mm: trigger page reclaim in alloc_contig_range() to stabilise watermarks
mm: extract reclaim code from __alloc_pages_direct_reclaim()
mm: Serialize access to min_free_kbytes
mm: page_isolation: MIGRATE_CMA isolation functions added
mm: mmzone: MIGRATE_CMA migration type added
mm: page_alloc: change fallbacks array handling
mm: page_alloc: introduce alloc_contig_range()
mm: compaction: export some of the functions
mm: compaction: introduce isolate_freepages_range()
mm: compaction: introduce map_pages()
mm: compaction: introduce isolate_migratepages_range()
mm: page_alloc: remove trailing whitespace
ARM: dma-mapping: add support for IOMMU mapper
ARM: dma-mapping: use alloc, mmap, free from dma_ops
ARM: dma-mapping: remove redundant code and do the cleanup
...
Conflicts:
arch/x86/include/asm/dma-mapping.h
Pull more networking updates from David Miller:
"Ok, everything from here on out will be bug fixes."
1) One final sync of wireless and bluetooth stuff from John Linville.
These changes have all been in his tree for more than a week, and
therefore have had the necessary -next exposure. John was just away
on a trip and didn't have a change to send the pull request until a
day or two ago.
2) Put back some defines in user exposed header file areas that were
removed during the tokenring purge. From Stephen Hemminger and Paul
Gortmaker.
3) A bug fix for UDP hash table allocation got lost in the pile due to
one of those "you got it.. no I've got it.." situations. :-)
From Tim Bird.
4) SKB coalescing in TCP needs to have stricter checks, otherwise we'll
try to coalesce overlapping frags and crash. Fix from Eric Dumazet.
5) RCU routing table lookups can race with free_fib_info(), causing
crashes when we deref the device pointers in the route. Fix by
releasing the net device in the RCU callback. From Yanmin Zhang.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (293 commits)
tcp: take care of overlaps in tcp_try_coalesce()
ipv4: fix the rcu race between free_fib_info and ip_route_output_slow
mm: add a low limit to alloc_large_system_hash
ipx: restore token ring define to include/linux/ipx.h
if: restore token ring ARP type to header
xen: do not disable netfront in dom0
phy/micrel: Fix ID of KSZ9021
mISDN: Add X-Tensions USB ISDN TA XC-525
gianfar:don't add FCB length to hard_header_len
Bluetooth: Report proper error number in disconnection
Bluetooth: Create flags for bt_sk()
Bluetooth: report the right security level in getsockopt
Bluetooth: Lock the L2CAP channel when sending
Bluetooth: Restore locking semantics when looking up L2CAP channels
Bluetooth: Fix a redundant and problematic incoming MTU check
Bluetooth: Add support for Foxconn/Hon Hai AR5BBU22 0489:E03C
Bluetooth: Fix EIR data generation for mgmt_device_found
Bluetooth: Fix Inquiry with RSSI event mask
Bluetooth: improve readability of l2cap_seq_list code
Bluetooth: Fix skb length calculation
...
UDP stack needs a minimum hash size value for proper operation and also
uses alloc_large_system_hash() for proper NUMA distribution of its hash
tables and automatic sizing depending on available system memory.
On some low memory situations, udp_table_init() must ignore the
alloc_large_system_hash() result and reallocs a bigger memory area.
As we cannot easily free old hash table, we leak it and kmemleak can
issue a warning.
This patch adds a low limit parameter to alloc_large_system_hash() to
solve this problem.
We then specify UDP_HTABLE_SIZE_MIN for UDP/UDPLite hash table
allocation.
Reported-by: Mark Asselstine <mark.asselstine@windriver.com>
Reported-by: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Here's the driver core, and other driver subsystems, pull request for
the 3.5-rc1 merge window.
Outside of a few minor driver core changes, we ended up with the
following different subsystem and core changes as well, due to
interdependancies on the driver core:
- hyperv driver updates
- drivers/memory being created and some drivers moved into it
- extcon driver subsystem created out of the old Android staging switch
driver code
- dynamic debug updates
- printk rework, and /dev/kmsg changes
All of this has been tested in the linux-next releases for a few weeks
with no reported problems.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg Kroah-Hartman:
"Here's the driver core, and other driver subsystems, pull request for
the 3.5-rc1 merge window.
Outside of a few minor driver core changes, we ended up with the
following different subsystem and core changes as well, due to
interdependancies on the driver core:
- hyperv driver updates
- drivers/memory being created and some drivers moved into it
- extcon driver subsystem created out of the old Android staging
switch driver code
- dynamic debug updates
- printk rework, and /dev/kmsg changes
All of this has been tested in the linux-next releases for a few weeks
with no reported problems.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"
Fix up conflicts in drivers/extcon/extcon-max8997.c where git noticed
that a patch to the deleted drivers/misc/max8997-muic.c driver needs to
be applied to this one.
* tag 'driver-core-3.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (90 commits)
uio_pdrv_genirq: get irq through platform resource if not set otherwise
memory: tegra{20,30}-mc: Remove empty *_remove()
printk() - isolate KERN_CONT users from ordinary complete lines
sysfs: get rid of some lockdep false positives
Drivers: hv: util: Properly handle version negotiations.
Drivers: hv: Get rid of an unnecessary check in vmbus_prep_negotiate_resp()
memory: tegra{20,30}-mc: Use dev_err_ratelimited()
driver core: Add dev_*_ratelimited() family
Driver Core: don't oops with unregistered driver in driver_find_device()
printk() - restore prefix/timestamp printing for multi-newline strings
printk: add stub for prepend_timestamp()
ARM: tegra30: Make MC optional in Kconfig
ARM: tegra20: Make MC optional in Kconfig
ARM: tegra30: MC: Remove unnecessary BUG*()
ARM: tegra20: MC: Remove unnecessary BUG*()
printk: correctly align __log_buf
ARM: tegra30: Add Tegra Memory Controller(MC) driver
ARM: tegra20: Add Tegra Memory Controller(MC) driver
printk() - restore timestamp printing at console output
printk() - do not merge continuation lines of different threads
...
__alloc_contig_migrate_range calls migrate_pages with wrong argument
for migrate_mode. Fix it.
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
alloc_contig_range() performs memory allocation so it also should keep
track on keeping the correct level of memory watermarks. This commit adds
a call to *_slowpath style reclaim to grab enough pages to make sure that
the final collection of contiguous pages from freelists will not starve
the system.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
CC: Michal Nazarewicz <mina86@mina86.com>
Tested-by: Rob Clark <rob.clark@linaro.org>
Tested-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Tested-by: Robert Nelson <robertcnelson@gmail.com>
Tested-by: Barry Song <Baohua.Song@csr.com>
This patch extracts common reclaim code from __alloc_pages_direct_reclaim()
function to separate function: __perform_reclaim() which can be later used
by alloc_contig_range().
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Tested-by: Rob Clark <rob.clark@linaro.org>
Tested-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Tested-by: Robert Nelson <robertcnelson@gmail.com>
Tested-by: Barry Song <Baohua.Song@csr.com>
There is a race between the min_free_kbytes sysctl, memory hotplug
and transparent hugepage support enablement. Memory hotplug uses a
zonelists_mutex to avoid a race when building zonelists. Reuse it to
serialise watermark updates.
[a.p.zijlstra@chello.nl: Older patch fixed the race with spinlock]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: Barry Song <Baohua.Song@csr.com>
This commit changes various functions that change pages and
pageblocks migrate type between MIGRATE_ISOLATE and
MIGRATE_MOVABLE in such a way as to allow to work with
MIGRATE_CMA migrate type.
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: Rob Clark <rob.clark@linaro.org>
Tested-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Tested-by: Robert Nelson <robertcnelson@gmail.com>
Tested-by: Barry Song <Baohua.Song@csr.com>
The MIGRATE_CMA migration type has two main characteristics:
(i) only movable pages can be allocated from MIGRATE_CMA
pageblocks and (ii) page allocator will never change migration
type of MIGRATE_CMA pageblocks.
This guarantees (to some degree) that page in a MIGRATE_CMA page
block can always be migrated somewhere else (unless there's no
memory left in the system).
It is designed to be used for allocating big chunks (eg. 10MiB)
of physically contiguous memory. Once driver requests
contiguous memory, pages from MIGRATE_CMA pageblocks may be
migrated away to create a contiguous block.
To minimise number of migrations, MIGRATE_CMA migration type
is the last type tried when page allocator falls back to other
migration types when requested.
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: Rob Clark <rob.clark@linaro.org>
Tested-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Tested-by: Robert Nelson <robertcnelson@gmail.com>
Tested-by: Barry Song <Baohua.Song@csr.com>
This commit adds a row for MIGRATE_ISOLATE type to the fallbacks array
which was missing from it. It also, changes the array traversal logic
a little making MIGRATE_RESERVE an end marker. The letter change,
removes the implicit MIGRATE_UNMOVABLE from the end of each row which
was read by __rmqueue_fallback() function.
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: Rob Clark <rob.clark@linaro.org>
Tested-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Tested-by: Robert Nelson <robertcnelson@gmail.com>
Tested-by: Barry Song <Baohua.Song@csr.com>
This commit adds the alloc_contig_range() function which tries
to allocate given range of pages. It tries to migrate all
already allocated pages that fall in the range thus freeing them.
Once all pages in the range are freed they are removed from the
buddy system thus allocated for the caller to use.
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: Rob Clark <rob.clark@linaro.org>
Tested-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Tested-by: Robert Nelson <robertcnelson@gmail.com>
Tested-by: Barry Song <Baohua.Song@csr.com>
Why is there less MemFree than there used to be? It perturbed a test,
so I've just been bisecting linux-next, and now find the offender went
upstream yesterday.
Commit 93278814d3 "mm: fix division by 0 in percpu_pagelist_fraction()"
mistakenly initialized percpu_pagelist_fraction to the sysctl's minimum 8,
which leaves 1/8th of memory on percpu lists (on each cpu??); but most of
us expect it to be left unset at 0 (and it's not then used as a divisor).
MemTotal: 8061476kB 8061476kB 8061476kB 8061476kB 8061476kB 8061476kB
Repetitive test with percpu_pagelist_fraction 8:
MemFree: 6948420kB 6237172kB 6949696kB 6840692kB 6949048kB 6862984kB
Same test with percpu_pagelist_fraction back to 0:
MemFree: 7945000kB 7944908kB 7948568kB 7949060kB 7948796kB 7948812kB
Signed-off-by: Hugh Dickins <hughd@google.com>
[ We really should fix the crazy sysctl interface too, but that's a
separate thing - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
percpu_pagelist_fraction_sysctl_handler() has only considered -EINVAL as
a possible error from proc_dointvec_minmax().
If any other error is returned, it would proceed to divide by zero since
percpu_pagelist_fraction wasn't getting initialized at any point. For
example, writing 0 bytes into the proc file would trigger the issue.
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Calculate a cpumask of CPUs with per-cpu pages in any zone and only send
an IPI requesting CPUs to drain these pages to the buddy allocator if they
actually have pages when asked to flush.
This patch saves 85%+ of IPIs asking to drain per-cpu pages in case of
severe memory pressure that leads to OOM since in these cases multiple,
possibly concurrent, allocation requests end up in the direct reclaim code
path so when the per-cpu pages end up reclaimed on first allocation
failure for most of the proceeding allocation attempts until the memory
pressure is off (possibly via the OOM killer) there are no per-cpu pages
on most CPUs (and there can easily be hundreds of them).
This also has the side effect of shortening the average latency of direct
reclaim by 1 or more order of magnitude since waiting for all the CPUs to
ACK the IPI takes a long time.
Tested by running "hackbench 400" on a 8 CPU x86 VM and observing the
difference between the number of direct reclaim attempts that end up in
drain_all_pages() and those were more then 1/2 of the online CPU had any
per-cpu page in them, using the vmstat counters introduced in the next
patch in the series and using proc/interrupts.
In the test sceanrio, this was seen to save around 3600 global
IPIs after trigerring an OOM on a concurrent workload:
$ cat /proc/vmstat | tail -n 2
pcp_global_drain 0
pcp_global_ipi_saved 0
$ cat /proc/interrupts | grep CAL
CAL: 1 2 1 2
2 2 2 2 Function call interrupts
$ hackbench 400
[OOM messages snipped]
$ cat /proc/vmstat | tail -n 2
pcp_global_drain 3647
pcp_global_ipi_saved 3642
$ cat /proc/interrupts | grep CAL
CAL: 6 13 6 3
3 3 1 2 7 Function call interrupts
Please note that if the global drain is removed from the direct reclaim
path as a patch from Mel Gorman currently suggests this should be replaced
with an on_each_cpu_cond invocation.
Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Acked-by: Michal Nazarewicz <mina86@mina86.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The size of coredump files is limited by RLIMIT_CORE, however, allocating
large amounts of memory results in three negative consequences:
- the coredumping process may be chosen for oom kill and quickly deplete
all memory reserves in oom conditions preventing further progress from
being made or tasks from exiting,
- the coredumping process may cause other processes to be oom killed
without fault of their own as the result of a SIGSEGV, for example, in
the coredumping process, or
- the coredumping process may result in a livelock while writing to the
dump file if it needs memory to allocate while other threads are in
the exit path waiting on the coredumper to complete.
This is fixed by implying __GFP_NORETRY in the page allocator for
coredumping processes when reclaim has failed so the allocations fail and
the process continues to exit.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
find_zone_movable_pfns_for_nodes() does not use its argument.
Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
add_from_early_node_map() is unused.
Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit c0ff7453bb ("cpuset,mm: fix no node to alloc memory when
changing cpuset's mems") wins a super prize for the largest number of
memory barriers entered into fast paths for one commit.
[get|put]_mems_allowed is incredibly heavy with pairs of full memory
barriers inserted into a number of hot paths. This was detected while
investigating at large page allocator slowdown introduced some time
after 2.6.32. The largest portion of this overhead was shown by
oprofile to be at an mfence introduced by this commit into the page
allocator hot path.
For extra style points, the commit introduced the use of yield() in an
implementation of what looks like a spinning mutex.
This patch replaces the full memory barriers on both read and write
sides with a sequence counter with just read barriers on the fast path
side. This is much cheaper on some architectures, including x86. The
main bulk of the patch is the retry logic if the nodemask changes in a
manner that can cause a false failure.
While updating the nodemask, a check is made to see if a false failure
is a risk. If it is, the sequence number gets bumped and parallel
allocators will briefly stall while the nodemask update takes place.
In a page fault test microbenchmark, oprofile samples from
__alloc_pages_nodemask went from 4.53% of all samples to 1.15%. The
actual results were
3.3.0-rc3 3.3.0-rc3
rc3-vanilla nobarrier-v2r1
Clients 1 UserTime 0.07 ( 0.00%) 0.08 (-14.19%)
Clients 2 UserTime 0.07 ( 0.00%) 0.07 ( 2.72%)
Clients 4 UserTime 0.08 ( 0.00%) 0.07 ( 3.29%)
Clients 1 SysTime 0.70 ( 0.00%) 0.65 ( 6.65%)
Clients 2 SysTime 0.85 ( 0.00%) 0.82 ( 3.65%)
Clients 4 SysTime 1.41 ( 0.00%) 1.41 ( 0.32%)
Clients 1 WallTime 0.77 ( 0.00%) 0.74 ( 4.19%)
Clients 2 WallTime 0.47 ( 0.00%) 0.45 ( 3.73%)
Clients 4 WallTime 0.38 ( 0.00%) 0.37 ( 1.58%)
Clients 1 Flt/sec/cpu 497620.28 ( 0.00%) 520294.53 ( 4.56%)
Clients 2 Flt/sec/cpu 414639.05 ( 0.00%) 429882.01 ( 3.68%)
Clients 4 Flt/sec/cpu 257959.16 ( 0.00%) 258761.48 ( 0.31%)
Clients 1 Flt/sec 495161.39 ( 0.00%) 517292.87 ( 4.47%)
Clients 2 Flt/sec 820325.95 ( 0.00%) 850289.77 ( 3.65%)
Clients 4 Flt/sec 1020068.93 ( 0.00%) 1022674.06 ( 0.26%)
MMTests Statistics: duration
Sys Time Running Test (seconds) 135.68 132.17
User+Sys Time Running Test (seconds) 164.2 160.13
Total Elapsed Time (seconds) 123.46 120.87
The overall improvement is small but the System CPU time is much
improved and roughly in correlation to what oprofile reported (these
performance figures are without profiling so skew is expected). The
actual number of page faults is noticeably improved.
For benchmarks like kernel builds, the overall benefit is marginal but
the system CPU time is slightly reduced.
To test the actual bug the commit fixed I opened two terminals. The
first ran within a cpuset and continually ran a small program that
faulted 100M of anonymous data. In a second window, the nodemask of the
cpuset was continually randomised in a loop.
Without the commit, the program would fail every so often (usually
within 10 seconds) and obviously with the commit everything worked fine.
With this patch applied, it also worked fine so the fix should be
functionally equivalent.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Miao Xie <miaox@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This cpu hotplug hook was accidentally removed in commit 00a62ce91e
("mm: fix Committed_AS underflow on large NR_CPUS environment")
The visible effect of this accident: some pages are borrowed in per-cpu
page-vectors. Truncate can deal with it, but these pages cannot be
reused while this cpu is offline. So this is like a temporary memory
leak.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Eric B Munson <ebmunson@us.ibm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The oom killer chooses not to kill a thread if:
- an eligible thread has already been oom killed and has yet to exit,
and
- an eligible thread is exiting but has yet to free all its memory and
is not the thread attempting to currently allocate memory.
SysRq+F manually invokes the global oom killer to kill a memory-hogging
task. This is normally done as a last resort to free memory when no
progress is being made or to test the oom killer itself.
For both uses, we always want to kill a thread and never defer. This
patch causes SysRq+F to always kill an eligible thread and can be used to
force a kill even if another oom killed thread has failed to exit.
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently a failed order-9 (transparent hugepage) compaction can lead to
memory compaction being temporarily disabled for a memory zone. Even if
we only need compaction for an order 2 allocation, eg. for jumbo frames
networking.
The fix is relatively straightforward: keep track of the highest order at
which compaction is succeeding, and only defer compaction for orders at
which compaction is failing.
Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When the number of dentry cache hash table entries gets too high
(2147483648 entries), as happens by default on a 16TB system, use of a
signed integer in the dcache_init() initialization loop prevents the
dentry_hashtable from getting initialized, causing a panic in
__d_lookup(). Fix this in dcache_init() and similar areas.
Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
page_zone() requires an online node otherwise we are accessing NULL
NODE_DATA. This is not an issue at the moment because node_zones are
located at the structure beginning but this might change in the future
so better be careful about that.
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the following NULL ptr dereference caused by
cat /sys/devices/system/memory/memory0/removable
Pid: 13979, comm: sed Not tainted 3.0.13-0.5-default #1 IBM BladeCenter LS21 -[7971PAM]-/Server Blade
RIP: __count_immobile_pages+0x4/0x100
Process sed (pid: 13979, threadinfo ffff880221c36000, task ffff88022e788480)
Call Trace:
is_pageblock_removable_nolock+0x34/0x40
is_mem_section_removable+0x74/0xf0
show_mem_removable+0x41/0x70
sysfs_read_file+0xfe/0x1c0
vfs_read+0xc7/0x130
sys_read+0x53/0xa0
system_call_fastpath+0x16/0x1b
We are crashing because we are trying to dereference NULL zone which
came from pfn=0 (struct page ffffea0000000000). According to the boot
log this page is marked reserved:
e820 update range: 0000000000000000 - 0000000000010000 (usable) ==> (reserved)
and early_node_map confirms that:
early_node_map[3] active PFN ranges
1: 0x00000010 -> 0x0000009c
1: 0x00000100 -> 0x000bffa3
1: 0x00100000 -> 0x00240000
The problem is that memory_present works in PAGE_SECTION_MASK aligned
blocks so the reserved range sneaks into the the section as well. This
also means that free_area_init_node will not take care of those reserved
pages and they stay uninitialized.
When we try to read the removable status we walk through all available
sections and hope that the zone is valid for all pages in the section.
But this is not true in this case as the zone and nid are not initialized.
We have only one node in this particular case and it is marked as node=1
(rather than 0) and that made the problem visible because page_to_nid will
return 0 and there are no zones on the node.
Let's check that the zone is valid and that the given pfn falls into its
boundaries and mark the section not removable. This might cause some
false positives, probably, but we do not have any sane way to find out
whether the page is reserved by the platform or it is just not used for
whatever other reasons.
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mostly we use "enum lru_list lru": change those few "l"s to "lru"s.
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If compaction is deferred, direct reclaim is used to try to free enough
pages for the allocation to succeed. For small high-orders, this has a
reasonable chance of success. However, if the caller has specified
__GFP_NO_KSWAPD to limit the disruption to the system, it makes more sense
to fail the allocation rather than stall the caller in direct reclaim.
This patch skips direct reclaim if compaction is deferred and the caller
specifies __GFP_NO_KSWAPD.
Async compaction only considers a subset of pages so it is possible for
compaction to be deferred prematurely and not enter direct reclaim even in
cases where it should. To compensate for this, this patch also defers
compaction only if sync compaction failed.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: Rik van Riel<riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andy Isaacson <adi@hexapodia.org>
Cc: Nai Xia <nai.xia@gmail.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If there is a zone below ZONE_NORMAL has present_pages, we can set node
state to N_NORMAL_MEMORY, no need to loop to end.
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Having a unified structure with a LRU list set for both global zones and
per-memcg zones allows to keep that code simple which deals with LRU
lists and does not care about the container itself.
Once the per-memcg LRU lists directly link struct pages, the isolation
function and all other list manipulations are shared between the memcg
case and the global LRU case.
Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Ying Han <yinghan@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__free_pages_bootmem() used to special-case higher-order frees to save
individual page checking with free_pages_bulk().
Nowadays, both zero order and non-zero order frees use free_pages(), which
checks each individual page anyway, and so there is little point in making
the distinction anymore. The higher-order loop will work just fine for
zero order pages.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 88f5acf88a ("mm: page allocator: adjust the per-cpu counter
threshold when memory is low") changed the form how free_pages is
calculated but it forgot that we used to do free_pages - ((1 << order) -
1) so we ended up with off-by-two when calculating free_pages.
Reported-by: Wang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The maximum number of dirty pages that exist in the system at any time is
determined by a number of pages considered dirtyable and a user-configured
percentage of those, or an absolute number in bytes.
This number of dirtyable pages is the sum of memory provided by all the
zones in the system minus their lowmem reserves and high watermarks, so
that the system can retain a healthy number of free pages without having
to reclaim dirty pages.
But there is a flaw in that we have a zoned page allocator which does not
care about the global state but rather the state of individual memory
zones. And right now there is nothing that prevents one zone from filling
up with dirty pages while other zones are spared, which frequently leads
to situations where kswapd, in order to restore the watermark of free
pages, does indeed have to write pages from that zone's LRU list. This
can interfere so badly with IO from the flusher threads that major
filesystems (btrfs, xfs, ext4) mostly ignore write requests from reclaim
already, taking away the VM's only possibility to keep such a zone
balanced, aside from hoping the flushers will soon clean pages from that
zone.
Enter per-zone dirty limits. They are to a zone's dirtyable memory what
the global limit is to the global amount of dirtyable memory, and try to
make sure that no single zone receives more than its fair share of the
globally allowed dirty pages in the first place. As the number of pages
considered dirtyable excludes the zones' lowmem reserves and high
watermarks, the maximum number of dirty pages in a zone is such that the
zone can always be balanced without requiring page cleaning.
As this is a placement decision in the page allocator and pages are
dirtied only after the allocation, this patch allows allocators to pass
__GFP_WRITE when they know in advance that the page will be written to and
become dirty soon. The page allocator will then attempt to allocate from
the first zone of the zonelist - which on NUMA is determined by the task's
NUMA memory policy - that has not exceeded its dirty limit.
At first glance, it would appear that the diversion to lower zones can
increase pressure on them, but this is not the case. With a full high
zone, allocations will be diverted to lower zones eventually, so it is
more of a shift in timing of the lower zone allocations. Workloads that
previously could fit their dirty pages completely in the higher zone may
be forced to allocate from lower zones, but the amount of pages that
"spill over" are limited themselves by the lower zones' dirty constraints,
and thus unlikely to become a problem.
For now, the problem of unfair dirty page distribution remains for NUMA
configurations where the zones allowed for allocation are in sum not big
enough to trigger the global dirty limits, wake up the flusher threads and
remedy the situation. Because of this, an allocation that could not
succeed on any of the considered zones is allowed to ignore the dirty
limits before going into direct reclaim or even failing the allocation,
until a future patch changes the global dirty throttling and flusher
thread activation so that they take individual zone states into account.
Test results
15M DMA + 3246M DMA32 + 504 Normal = 3765M memory
40% dirty ratio
16G USB thumb drive
10 runs of dd if=/dev/zero of=disk/zeroes bs=32k count=$((10 << 15))
seconds nr_vmscan_write
(stddev) min| median| max
xfs
vanilla: 549.747( 3.492) 0.000| 0.000| 0.000
patched: 550.996( 3.802) 0.000| 0.000| 0.000
fuse-ntfs
vanilla: 1183.094(53.178) 54349.000| 59341.000| 65163.000
patched: 558.049(17.914) 0.000| 0.000| 43.000
btrfs
vanilla: 573.679(14.015) 156657.000| 460178.000| 606926.000
patched: 563.365(11.368) 0.000| 0.000| 1362.000
ext4
vanilla: 561.197(15.782) 0.000|2725438.000|4143837.000
patched: 568.806(17.496) 0.000| 0.000| 0.000
Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Tested-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Per-zone dirty limits try to distribute page cache pages allocated for
writing across zones in proportion to the individual zone sizes, to reduce
the likelihood of reclaim having to write back individual pages from the
LRU lists in order to make progress.
This patch:
The amount of dirtyable pages should not include the full number of free
pages: there is a number of reserved pages that the page allocator and
kswapd always try to keep free.
The closer (reclaimable pages - dirty pages) is to the number of reserved
pages, the more likely it becomes for reclaim to run into dirty pages:
+----------+ ---
| anon | |
+----------+ |
| | |
| | -- dirty limit new -- flusher new
| file | | |
| | | |
| | -- dirty limit old -- flusher old
| | |
+----------+ --- reclaim
| reserved |
+----------+
| kernel |
+----------+
This patch introduces a per-zone dirty reserve that takes both the lowmem
reserve as well as the high watermark of the zone into account, and a
global sum of those per-zone values that is subtracted from the global
amount of dirtyable pages. The lowmem reserve is unavailable to page
cache allocations and kswapd tries to keep the high watermark free. We
don't want to end up in a situation where reclaim has to clean pages in
order to balance zones.
Not treating reserved pages as dirtyable on a global level is only a
conceptual fix. In reality, dirty pages are not distributed equally
across zones and reclaim runs into dirty pages on a regular basis.
But it is important to get this right before tackling the problem on a
per-zone level, where the distance between reclaim and the dirty pages is
mostly much smaller in absolute numbers.
[akpm@linux-foundation.org: fix highmem build]
Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With CONFIG_DEBUG_PAGEALLOC configured, the CPU will generate an exception
on access (read,write) to an unallocated page, which permits us to catch
code which corrupts memory. However the kernel is trying to maximise
memory usage, hence there are usually few free pages in the system and
buggy code usually corrupts some crucial data.
This patch changes the buddy allocator to keep more free/protected pages
and to interlace free/protected and allocated pages to increase the
probability of catching corruption.
When the kernel is compiled with CONFIG_DEBUG_PAGEALLOC,
debug_guardpage_minorder defines the minimum order used by the page
allocator to grant a request. The requested size will be returned with
the remaining pages used as guard pages.
The default value of debug_guardpage_minorder is zero: no change from
current behaviour.
[akpm@linux-foundation.org: tweak documentation, s/flg/flag/]
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Colin Cross reported;
Under the following conditions, __alloc_pages_slowpath can loop forever:
gfp_mask & __GFP_WAIT is true
gfp_mask & __GFP_FS is false
reclaim and compaction make no progress
order <= PAGE_ALLOC_COSTLY_ORDER
These conditions happen very often during suspend and resume,
when pm_restrict_gfp_mask() effectively converts all GFP_KERNEL
allocations into __GFP_WAIT.
The oom killer is not run because gfp_mask & __GFP_FS is false,
but should_alloc_retry will always return true when order is less
than PAGE_ALLOC_COSTLY_ORDER.
In his fix, he avoided retrying the allocation if reclaim made no progress
and __GFP_FS was not set. The problem is that this would result in
GFP_NOIO allocations failing that previously succeeded which would be very
unfortunate.
The big difference between GFP_NOIO and suspend converting GFP_KERNEL to
behave like GFP_NOIO is that normally flushers will be cleaning pages and
kswapd reclaims pages allowing GFP_NOIO to succeed after a short delay.
The same does not necessarily apply during suspend as the storage device
may be suspended.
This patch special cases the suspend case to fail the page allocation if
reclaim cannot make progress and adds some documentation on how
gfp_allowed_mask is currently used. Failing allocations like this may
cause suspend to abort but that is better than a livelock.
[mgorman@suse.de: Rework fix to be suspend specific]
[rientjes@google.com: Move suspended device check to should_alloc_retry]
Reported-by: Colin Cross <ccross@android.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When min_free_kbytes is updated, some pageblocks are marked
MIGRATE_RESERVE. Ordinarily, this work is unnoticable as it happens early
in boot but on large machines with 1TB of memory, this has been reported
to delay boot times, probably due to the NUMA distances involved.
The bulk of the work is due to calling calling pageblock_is_reserved() an
unnecessary amount of times and accessing far more struct page metadata
than is necessary. This patch significantly reduces the amount of work
done by setup_zone_migrate_reserve() improving boot times on 1TB machines.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rename mm_page_free_direct into mm_page_free and mm_pagevec_free into
mm_page_free_batched
Since v2.6.33-5426-gc475dab the kernel triggers mm_page_free_direct for
all freed pages, not only for directly freed. So, let's name it properly.
For pages freed via page-list we also trigger mm_page_free_batched event.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It not exported and now nobody uses it.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (53 commits)
Kconfig: acpi: Fix typo in comment.
misc latin1 to utf8 conversions
devres: Fix a typo in devm_kfree comment
btrfs: free-space-cache.c: remove extra semicolon.
fat: Spelling s/obsolate/obsolete/g
SCSI, pmcraid: Fix spelling error in a pmcraid_err() call
tools/power turbostat: update fields in manpage
mac80211: drop spelling fix
types.h: fix comment spelling for 'architectures'
typo fixes: aera -> area, exntension -> extension
devices.txt: Fix typo of 'VMware'.
sis900: Fix enum typo 'sis900_rx_bufer_status'
decompress_bunzip2: remove invalid vi modeline
treewide: Fix comment and string typo 'bufer'
hyper-v: Update MAINTAINERS
treewide: Fix typos in various parts of the kernel, and fix some comments.
clockevents: drop unknown Kconfig symbol GENERIC_CLOCKEVENTS_MIGR
gpio: Kconfig: drop unknown symbol 'CS5535_GPIO'
leds: Kconfig: Fix typo 'D2NET_V2'
sound: Kconfig: drop unknown symbol ARCH_CLPS7500
...
Fix up trivial conflicts in arch/powerpc/platforms/40x/Kconfig (some new
kconfig additions, close to removed commented-out old ones)
* 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (165 commits)
reiserfs: Properly display mount options in /proc/mounts
vfs: prevent remount read-only if pending removes
vfs: count unlinked inodes
vfs: protect remounting superblock read-only
vfs: keep list of mounts for each superblock
vfs: switch ->show_options() to struct dentry *
vfs: switch ->show_path() to struct dentry *
vfs: switch ->show_devname() to struct dentry *
vfs: switch ->show_stats to struct dentry *
switch security_path_chmod() to struct path *
vfs: prefer ->dentry->d_sb to ->mnt->mnt_sb
vfs: trim includes a bit
switch mnt_namespace ->root to struct mount
vfs: take /proc/*/mounts and friends to fs/proc_namespace.c
vfs: opencode mntget() mnt_set_mountpoint()
vfs: spread struct mount - remaining argument of next_mnt()
vfs: move fsnotify junk to struct mount
vfs: move mnt_devname
vfs: move mnt_list to struct mount
vfs: switch pnode.h macros to struct mount *
...
setup_zone_migrate_reserve() expects that zone->start_pfn starts at
pageblock_nr_pages aligned pfn otherwise we could access beyond an
existing memblock resulting in the following panic if
CONFIG_HOLES_IN_ZONE is not configured and we do not check pfn_valid:
IP: [<c02d331d>] setup_zone_migrate_reserve+0xcd/0x180
*pdpt = 0000000000000000 *pde = f000ff53f000ff53
Oops: 0000 [#1] SMP
Pid: 1, comm: swapper Not tainted 3.0.7-0.7-pae #1 VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform
EIP: 0060:[<c02d331d>] EFLAGS: 00010006 CPU: 0
EIP is at setup_zone_migrate_reserve+0xcd/0x180
EAX: 000c0000 EBX: f5801fc0 ECX: 000c0000 EDX: 00000000
ESI: 000c01fe EDI: 000c01fe EBP: 00140000 ESP: f2475f58
DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
Process swapper (pid: 1, ti=f2474000 task=f2472cd0 task.ti=f2474000)
Call Trace:
[<c02d389c>] __setup_per_zone_wmarks+0xec/0x160
[<c02d3a1f>] setup_per_zone_wmarks+0xf/0x20
[<c08a771c>] init_per_zone_wmark_min+0x27/0x86
[<c020111b>] do_one_initcall+0x2b/0x160
[<c086639d>] kernel_init+0xbe/0x157
[<c05cae26>] kernel_thread_helper+0x6/0xd
Code: a5 39 f5 89 f7 0f 46 fd 39 cf 76 40 8b 03 f6 c4 08 74 32 eb 91 90 89 c8 c1 e8 0e 0f be 80 80 2f 86 c0 8b 14 85 60 2f 86 c0 89 c8 <2b> 82 b4 12 00 00 c1 e0 05 03 82 ac 12 00 00 8b 00 f6 c4 08 0f
EIP: [<c02d331d>] setup_zone_migrate_reserve+0xcd/0x180 SS:ESP 0068:f2475f58
CR2: 00000000000012b4
We crashed in pageblock_is_reserved() when accessing pfn 0xc0000 because
highstart_pfn = 0x36ffe.
The issue was introduced in 3.0-rc1 by 6d3163ce ("mm: check if any page
in a pageblock is reserved before marking it MIGRATE_RESERVE").
Make sure that start_pfn is always aligned to pageblock_nr_pages to
ensure that pfn_valid s always called at the start of each pageblock.
Architectures with holes in pageblocks will be correctly handled by
pfn_valid_within in pageblock_is_reserved.
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Tested-by: Dang Bo <bdang@vmware.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Arve Hjnnevg <arve@android.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org> [3.0+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 70b50f94f1 ("mm: thp: tail page refcounting fix") keeps all
page_tail->_count zero at all times. But the current kernel does not
set page_tail->_count to zero if a 1GB page is utilized. So when an
IOMMU 1GB page is used by KVM, it wil result in a kernel oops because a
tail page's _count does not equal zero.
kernel BUG at include/linux/mm.h:386!
invalid opcode: 0000 [#1] SMP
Call Trace:
gup_pud_range+0xb8/0x19d
get_user_pages_fast+0xcb/0x192
? trace_hardirqs_off+0xd/0xf
hva_to_pfn+0x119/0x2f2
gfn_to_pfn_memslot+0x2c/0x2e
kvm_iommu_map_pages+0xfd/0x1c1
kvm_iommu_map_memslots+0x7c/0xbd
kvm_iommu_map_guest+0xaa/0xbf
kvm_vm_ioctl_assigned_device+0x2ef/0xa47
kvm_vm_ioctl+0x36c/0x3a2
do_vfs_ioctl+0x49e/0x4e4
sys_ioctl+0x5a/0x7c
system_call_fastpath+0x16/0x1b
RIP gup_huge_pud+0xf2/0x159
Signed-off-by: Youquan Song <youquan.song@intel.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now all ARCH_POPULATES_NODE_MAP archs select HAVE_MEBLOCK_NODE_MAP -
there's no user of early_node_map[] left. Kill early_node_map[] and
replace ARCH_POPULATES_NODE_MAP with HAVE_MEMBLOCK_NODE_MAP. Also,
relocate for_each_mem_pfn_range() and helper from mm.h to memblock.h
as page_alloc.c would no longer host an alternative implementation.
This change is ultimately one to one mapping and shouldn't cause any
observable difference; however, after the recent changes, there are
some functions which now would fit memblock.c better than page_alloc.c
and dependency on HAVE_MEMBLOCK_NODE_MAP instead of HAVE_MEMBLOCK
doesn't make much sense on some of them. Further cleanups for
functions inside HAVE_MEMBLOCK_NODE_MAP in mm.h would be nice.
-v2: Fix compile bug introduced by mis-spelling
CONFIG_HAVE_MEMBLOCK_NODE_MAP to CONFIG_MEMBLOCK_HAVE_NODE_MAP in
mmzone.h. Reported by Stephen Rothwell.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Chen Liqin <liqin.chen@sunplusct.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Conflicts & resolutions:
* arch/x86/xen/setup.c
dc91c728fd "xen: allow extra memory to be in multiple regions"
24aa07882b "memblock, x86: Replace memblock_x86_reserve/free..."
conflicted on xen_add_extra_mem() updates. The resolution is
trivial as the latter just want to replace
memblock_x86_reserve_range() with memblock_reserve().
* drivers/pci/intel-iommu.c
166e9278a3 "x86/ia64: intel-iommu: move to drivers/iommu/"
5dfe8660a3 "bootmem: Replace work_with_active_regions() with..."
conflicted as the former moved the file under drivers/iommu/.
Resolved by applying the chnages from the latter on the moved
file.
* mm/Kconfig
6661672053 "memblock: add NO_BOOTMEM config symbol"
c378ddd53f "memblock, x86: Make ARCH_DISCARD_MEMBLOCK a config option"
conflicted trivially. Both added config options. Just
letting both add their own options resolves the conflict.
* mm/memblock.c
d1f0ece6cd "mm/memblock.c: small function definition fixes"
ed7b56a799 "memblock: Remove memblock_memory_can_coalesce()"
confliected. The former updates function removed by the
latter. Resolution is trivial.
Signed-off-by: Tejun Heo <tj@kernel.org>
Only tail pages point at the head page using their ->first_page fields.
Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Add __attribute__((format (printf...) to the function to validate format
and arguments. Use vsprintf extension %pV to avoid any possible message
interleaving. Coalesce format string. Convert printks/pr_warning to
pr_warn.
[akpm@linux-foundation.org: use the __printf() macro]
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When we get a bad_page bug report, it's useful to see what modules the
user had loaded.
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
init_fault_attr_dentries() is used to export fault_attr via debugfs.
But it can only export it in debugfs root directory.
Per Forlin is working on mmc_fail_request which adds support to inject
data errors after a completed host transfer in MMC subsystem.
The fault_attr for mmc_fail_request should be defined per mmc host and
export it in debugfs directory per mmc host like
/sys/kernel/debug/mmc0/mmc_fail_request.
init_fault_attr_dentries() doesn't help for mmc_fail_request. So this
introduces fault_create_debugfs_attr() which is able to create a
directory in the arbitrary directory and replace
init_fault_attr_dentries().
[akpm@linux-foundation.org: extraneous semicolon, per Randy]
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Tested-by: Per Forlin <per.forlin@linaro.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now cleanup_fault_attr_dentries() recursively removes a directory, So we
can simplify the error handling in the initialization code and no need
to hold dentry structs for each debugfs file.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use debugfs_remove_recursive() to simplify initialization and
deinitialization of fault injection debugfs files.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With zone_reclaim_mode enabled, it's possible for zones to be considered
full in the zonelist_cache so they are skipped in the future. If the
process enters direct reclaim, the ZLC may still consider zones to be full
even after reclaiming pages. Reconsider all zones for allocation if
direct reclaim returns successfully.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There have been a small number of complaints about significant stalls
while copying large amounts of data on NUMA machines reported on a
distribution bugzilla. In these cases, zone_reclaim was enabled by
default due to large NUMA distances. In general, the complaints have not
been about the workload itself unless it was a file server (in which case
the recommendation was disable zone_reclaim).
The stalls are mostly due to significant amounts of time spent scanning
the preferred zone for pages to free. After a failure, it might fallback
to another node (as zonelists are often node-ordered rather than
zone-ordered) but stall quickly again when the next allocation attempt
occurs. In bad cases, each page allocated results in a full scan of the
preferred zone.
Patch 1 checks the preferred zone for recent allocation failure
which is particularly important if zone_reclaim has failed
recently. This avoids rescanning the zone in the near future and
instead falling back to another node. This may hurt node locality
in some cases but a failure to zone_reclaim is more expensive than
a remote access.
Patch 2 clears the zlc information after direct reclaim.
Otherwise, zone_reclaim can mark zones full, direct reclaim can
reclaim enough pages but the zone is still not considered for
allocation.
This was tested on a 24-thread 2-node x86_64 machine. The tests were
focused on large amounts of IO. All tests were bound to the CPUs on
node-0 to avoid disturbances due to processes being scheduled on different
nodes. The kernels tested are
3.0-rc6-vanilla Vanilla 3.0-rc6
zlcfirst Patch 1 applied
zlcreconsider Patches 1+2 applied
FS-Mark
./fs_mark -d /tmp/fsmark-10813 -D 100 -N 5000 -n 208 -L 35 -t 24 -S0 -s 524288
fsmark-3.0-rc6 3.0-rc6 3.0-rc6
vanilla zlcfirs zlcreconsider
Files/s min 54.90 ( 0.00%) 49.80 (-10.24%) 49.10 (-11.81%)
Files/s mean 100.11 ( 0.00%) 135.17 (25.94%) 146.93 (31.87%)
Files/s stddev 57.51 ( 0.00%) 138.97 (58.62%) 158.69 (63.76%)
Files/s max 361.10 ( 0.00%) 834.40 (56.72%) 802.40 (55.00%)
Overhead min 76704.00 ( 0.00%) 76501.00 ( 0.27%) 77784.00 (-1.39%)
Overhead mean 1485356.51 ( 0.00%) 1035797.83 (43.40%) 1594680.26 (-6.86%)
Overhead stddev 1848122.53 ( 0.00%) 881489.88 (109.66%) 1772354.90 ( 4.27%)
Overhead max 7989060.00 ( 0.00%) 3369118.00 (137.13%) 10135324.00 (-21.18%)
MMTests Statistics: duration
User/Sys Time Running Test (seconds) 501.49 493.91 499.93
Total Elapsed Time (seconds) 2451.57 2257.48 2215.92
MMTests Statistics: vmstat
Page Ins 46268 63840 66008
Page Outs 90821596 90671128 88043732
Swap Ins 0 0 0
Swap Outs 0 0 0
Direct pages scanned 13091697 8966863 8971790
Kswapd pages scanned 0 1830011 1831116
Kswapd pages reclaimed 0 1829068 1829930
Direct pages reclaimed 13037777 8956828 8648314
Kswapd efficiency 100% 99% 99%
Kswapd velocity 0.000 810.643 826.346
Direct efficiency 99% 99% 96%
Direct velocity 5340.128 3972.068 4048.788
Percentage direct scans 100% 83% 83%
Page writes by reclaim 0 3 0
Slabs scanned 796672 720640 720256
Direct inode steals 7422667 7160012 7088638
Kswapd inode steals 0 1736840 2021238
Test completes far faster with a large increase in the number of files
created per second. Standard deviation is high as a small number of
iterations were much higher than the mean. The number of pages scanned by
zone_reclaim is reduced and kswapd is used for more work.
LARGE DD
3.0-rc6 3.0-rc6 3.0-rc6
vanilla zlcfirst zlcreconsider
download tar 59 ( 0.00%) 59 ( 0.00%) 55 ( 7.27%)
dd source files 527 ( 0.00%) 296 (78.04%) 320 (64.69%)
delete source 36 ( 0.00%) 19 (89.47%) 20 (80.00%)
MMTests Statistics: duration
User/Sys Time Running Test (seconds) 125.03 118.98 122.01
Total Elapsed Time (seconds) 624.56 375.02 398.06
MMTests Statistics: vmstat
Page Ins 3594216 439368 407032
Page Outs 23380832 23380488 23377444
Swap Ins 0 0 0
Swap Outs 0 436 287
Direct pages scanned 17482342 69315973 82864918
Kswapd pages scanned 0 519123 575425
Kswapd pages reclaimed 0 466501 522487
Direct pages reclaimed 5858054 2732949 2712547
Kswapd efficiency 100% 89% 90%
Kswapd velocity 0.000 1384.254 1445.574
Direct efficiency 33% 3% 3%
Direct velocity 27991.453 184832.737 208171.929
Percentage direct scans 100% 99% 99%
Page writes by reclaim 0 5082 13917
Slabs scanned 17280 29952 35328
Direct inode steals 115257 1431122 332201
Kswapd inode steals 0 0 979532
This test downloads a large tarfile and copies it with dd a number of
times - similar to the most recent bug report I've dealt with. Time to
completion is reduced. The number of pages scanned directly is still
disturbingly high with a low efficiency but this is likely due to the
number of dirty pages encountered. The figures could probably be improved
with more work around how kswapd is used and how dirty pages are handled
but that is separate work and this result is significant on its own.
Streaming Mapped Writer
MMTests Statistics: duration
User/Sys Time Running Test (seconds) 124.47 111.67 112.64
Total Elapsed Time (seconds) 2138.14 1816.30 1867.56
MMTests Statistics: vmstat
Page Ins 90760 89124 89516
Page Outs 121028340 120199524 120736696
Swap Ins 0 86 55
Swap Outs 0 0 0
Direct pages scanned 114989363 96461439 96330619
Kswapd pages scanned 56430948 56965763 57075875
Kswapd pages reclaimed 27743219 27752044 27766606
Direct pages reclaimed 49777 46884 36655
Kswapd efficiency 49% 48% 48%
Kswapd velocity 26392.541 31363.631 30561.736
Direct efficiency 0% 0% 0%
Direct velocity 53780.091 53108.759 51581.004
Percentage direct scans 67% 62% 62%
Page writes by reclaim 385 122 1513
Slabs scanned 43008 39040 42112
Direct inode steals 0 10 8
Kswapd inode steals 733 534 477
This test just creates a large file mapping and writes to it linearly.
Time to completion is again reduced.
The gains are mostly down to two things. In many cases, there is less
scanning as zone_reclaim simply gives up faster due to recent failures.
The second reason is that memory is used more efficiently. Instead of
scanning the preferred zone every time, the allocator falls back to
another zone and uses it instead improving overall memory utilisation.
This patch: initialise ZLC for first zone eligible for zone_reclaim.
The zonelist cache (ZLC) is used among other things to record if
zone_reclaim() failed for a particular zone recently. The intention is to
avoid a high cost scanning extremely long zonelists or scanning within the
zone uselessly.
Currently the zonelist cache is setup only after the first zone has been
considered and zone_reclaim() has been called. The objective was to avoid
a costly setup but zone_reclaim is itself quite expensive. If it is
failing regularly such as the first eligible zone having mostly mapped
pages, the cost in scanning and allocation stalls is far higher than the
ZLC initialisation step.
This patch initialises ZLC before the first eligible zone calls
zone_reclaim(). Once initialised, it is checked whether the zone failed
zone_reclaim recently. If it has, the zone is skipped. As the first zone
is now being checked, additional care has to be taken about zones marked
full. A zone can be marked "full" because it should not have enough
unmapped pages for zone_reclaim but this is excessive as direct reclaim or
kswapd may succeed where zone_reclaim fails. Only mark zones "full" after
zone_reclaim fails if it failed to reclaim enough pages after scanning.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
From 83103b92f3234ec830852bbc5c45911bd6cbdb20 Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Thu, 14 Jul 2011 11:22:16 +0200
Add optional region->nid which can be enabled by arch using
CONFIG_HAVE_MEMBLOCK_NODE_MAP. When enabled, memblock also carries
NUMA node information and replaces early_node_map[].
Newly added memblocks have MAX_NUMNODES as nid. Arch can then call
memblock_set_node() to set node information. memblock takes care of
merging and node affine allocations w.r.t. node information.
When MEMBLOCK_NODE_MAP is enabled, early_node_map[], related data
structures and functions to manipulate and iterate it are disabled.
memblock version of __next_mem_pfn_range() is provided such that
for_each_mem_pfn_range() behaves the same and its users don't have to
be updated.
-v2: Yinghai spotted section mismatch caused by missing
__init_memblock in memblock_set_node(). Fixed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20110714094342.GF3455@htj.dyndns.org
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
With the previous changes, generic NUMA aware memblock API has feature
parity with memblock_x86_find_in_range_node(). There currently are
two users - x86 setup_node_data() and __alloc_memory_core_early() in
nobootmem.c.
This patch converts the former to use memblock_alloc_nid() and the
latter memblock_find_range_in_node(), and kills
memblock_x86_find_in_range_node() and related functions including
find_memory_early_core_early() in page_alloc.c.
Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/1310460395-30913-9-git-send-email-tj@kernel.org
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The previous patch added for_each_mem_pfn_range() which is more
versatile than for_each_active_range_index_in_nid(). This patch
replaces for_each_active_range_index_in_nid() and open coded
early_node_map[] walks with for_each_mem_pfn_range().
All conversions in this patch are straight-forward and shouldn't cause
any functional difference. After the conversions,
for_each_active_range_index_in_nid() doesn't have any user left and is
removed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/1310460395-30913-4-git-send-email-tj@kernel.org
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
__absent_pages_in_range() was needlessly complex. Reimplement it
using for_each_mem_pfn_range().
Also, update zone_absent_pages_in_node() such that it doesn't call
__absent_pages_in_range() with @zone_start_pfn which is larger than
@zone_end_pfn.
Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/1310460395-30913-3-git-send-email-tj@kernel.org
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Callback based iteration is cumbersome and much less useful than
for_each_*() iterator. This patch implements for_each_mem_pfn_range()
which replaces work_with_active_regions(). All the current users of
work_with_active_regions() are converted.
This simplifies walking over early_node_map and will allow converting
internal logics in page_alloc to use iterator instead of walking
early_node_map directly, which in turn will enable moving node
information to memblock.
powerpc change is only compile tested.
Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20110714074610.GD3455@htj.dyndns.org
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
25818f0f28 (memblock: Make MEMBLOCK_ERROR be 0) thankfully made
MEMBLOCK_ERROR 0 and there already are codes which expect error return
to be 0. There's no point in keeping MEMBLOCK_ERROR around. End its
misery.
Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/1310457490-3356-6-git-send-email-tj@kernel.org
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
a226f6c899 (FRV: Clean up bootmem allocator's page freeing algorithm)
separated out __free_pages_bootmem() from free_all_bootmem_core().
__free_pages_bootmem() takes @order argument but it assumes @order is
either 0 or ilog2(BITS_PER_LONG). Note that all the current users
match that assumption and this doesn't cause actual problems.
Fix it by using 1 << order instead of BITS_PER_LONG.
Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/1310457490-3356-3-git-send-email-tj@kernel.org
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
SPARSEMEM w/o VMEMMAP and DISCONTIGMEM, both used only on 32bit, use
sections array to map pfn to nid which is limited in granularity. If
NUMA nodes are laid out such that the mapping cannot be accurate, boot
will fail triggering BUG_ON() in mminit_verify_page_links().
On 32bit, it's 512MiB w/ PAE and SPARSEMEM. This seems to have been
granular enough until commit 2706a0bf7b (x86, NUMA: Enable
CONFIG_AMD_NUMA on 32bit too). Apparently, there is a machine which
aligns NUMA nodes to 128MiB and has only AMD NUMA but not SRAT. This
led to the following BUG_ON().
On node 0 totalpages: 2096615
DMA zone: 32 pages used for memmap
DMA zone: 0 pages reserved
DMA zone: 3927 pages, LIFO batch:0
Normal zone: 1740 pages used for memmap
Normal zone: 220978 pages, LIFO batch:31
HighMem zone: 16405 pages used for memmap
HighMem zone: 1853533 pages, LIFO batch:31
BUG: Int 6: CR2 (null)
EDI (null) ESI 00000002 EBP 00000002 ESP c1543ecc
EBX f2400000 EDX 00000006 ECX (null) EAX 00000001
err (null) EIP c16209aa CS 00000060 flg 00010002
Stack: f2400000 00220000 f7200800 c1620613 00220000 01000000 04400000 00238000
(null) f7200000 00000002 f7200b58 f7200800 c1620929 000375fe (null)
f7200b80 c16395f0 00200a02 f7200a80 (null) 000375fe 00000002 (null)
Pid: 0, comm: swapper Not tainted 2.6.39-rc5-00181-g2706a0b #17
Call Trace:
[<c136b1e5>] ? early_fault+0x2e/0x2e
[<c16209aa>] ? mminit_verify_page_links+0x12/0x42
[<c1620613>] ? memmap_init_zone+0xaf/0x10c
[<c1620929>] ? free_area_init_node+0x2b9/0x2e3
[<c1607e99>] ? free_area_init_nodes+0x3f2/0x451
[<c1601d80>] ? paging_init+0x112/0x118
[<c15f578d>] ? setup_arch+0x791/0x82f
[<c15f43d9>] ? start_kernel+0x6a/0x257
This patch implements node_map_pfn_alignment() which determines
maximum internode alignment and update numa_register_memblks() to
reject NUMA configuration if alignment exceeds the pfn -> nid mapping
granularity of the memory model as determined by PAGES_PER_SECTION.
This makes the problematic machine boot w/ flatmem by rejecting the
NUMA config and provides protection against crazy NUMA configurations.
Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20110712074534.GB2872@htj.dyndns.org
LKML-Reference: <20110628174613.GP478@escobedo.osrc.amd.com>
Reported-and-Tested-by: Hans Rosenfeld <hans.rosenfeld@amd.com>
Cc: Conny Seidel <conny.seidel@amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This reverts commit a197b59ae6.
As rmk says:
"Commit a197b59ae6 (mm: fail GFP_DMA allocations when ZONE_DMA is not
configured) is causing regressions on ARM with various drivers which
use GFP_DMA.
The behaviour up until now has been to silently ignore that flag when
CONFIG_ZONE_DMA is not enabled, and to allocate from the normal zone.
However, as a result of the above commit, such allocations now fail
which causes drivers to fail. These are regressions compared to the
previous kernel version."
so just revert it.
Requested-by: Russell King <linux@arm.linux.org.uk>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
During memory reclaim we determine the number of pages to be scanned per
zone as
(anon + file) >> priority.
Assume
scan = (anon + file) >> priority.
If scan < SWAP_CLUSTER_MAX, the scan will be skipped for this time and
priority gets higher. This has some problems.
1. This increases priority as 1 without any scan.
To do scan in this priority, amount of pages should be larger than 512M.
If pages>>priority < SWAP_CLUSTER_MAX, it's recorded and scan will be
batched, later. (But we lose 1 priority.)
If memory size is below 16M, pages >> priority is 0 and no scan in
DEF_PRIORITY forever.
2. If zone->all_unreclaimabe==true, it's scanned only when priority==0.
So, x86's ZONE_DMA will never be recoverred until the user of pages
frees memory by itself.
3. With memcg, the limit of memory can be small. When using small memcg,
it gets priority < DEF_PRIORITY-2 very easily and need to call
wait_iff_congested().
For doing scan before priorty=9, 64MB of memory should be used.
Then, this patch tries to scan SWAP_CLUSTER_MAX of pages in force...when
1. the target is enough small.
2. it's kswapd or memcg reclaim.
Then we can avoid rapid priority drop and may be able to recover
all_unreclaimable in a small zones. And this patch removes nr_saved_scan.
This will allow scanning in this priority even when pages >> priority is
very small.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Ying Han <yinghan@google.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I believe I found a problem in __alloc_pages_slowpath, which allows a
process to get stuck endlessly looping, even when lots of memory is
available.
Running an I/O and memory intensive stress-test I see a 0-order page
allocation with __GFP_IO and __GFP_WAIT, running on a system with very
little free memory. Right about the same time that the stress-test gets
killed by the OOM-killer, the utility trying to allocate memory gets stuck
in __alloc_pages_slowpath even though most of the systems memory was freed
by the oom-kill of the stress-test.
The utility ends up looping from the rebalance label down through the
wait_iff_congested continiously. Because order=0,
__alloc_pages_direct_compact skips the call to get_page_from_freelist.
Because all of the reclaimable memory on the system has already been
reclaimed, __alloc_pages_direct_reclaim skips the call to
get_page_from_freelist. Since there is no __GFP_FS flag, the block with
__alloc_pages_may_oom is skipped. The loop hits the wait_iff_congested,
then jumps back to rebalance without ever trying to
get_page_from_freelist. This loop repeats infinitely.
The test case is pretty pathological. Running a mix of I/O stress-tests
that do a lot of fork() and consume all of the system memory, I can pretty
reliably hit this on 600 nodes, in about 12 hours. 32GB/node.
Signed-off-by: Andrew Barry <abarry@cray.com>
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: Rik van Riel<riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The page allocator will improperly return a page from ZONE_NORMAL even
when __GFP_DMA is passed if CONFIG_ZONE_DMA is disabled. The caller
expects DMA memory, perhaps for ISA devices with 16-bit address registers,
and may get higher memory resulting in undefined behavior.
This patch causes the page allocator to return NULL in such circumstances
with a warning emitted to the kernel log on the first occurrence.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This fixes a problem where the first pageblock got marked MIGRATE_RESERVE
even though it only had a few free pages. eg, On current ARM port, The
kernel starts at offset 0x8000 to leave room for boot parameters, and the
memory is freed later.
This in turn caused no contiguous memory to be reserved and frequent
kswapd wakeups that emptied the caches to get more contiguous memory.
Unfortunatelly, ARM needs order-2 allocation for pgd (see
arm/mm/pgd.c#pgd_alloc()). Therefore the issue is not minor nor easy
avoidable.
[kosaki.motohiro@jp.fujitsu.com: added some explanation]
[kosaki.motohiro@jp.fujitsu.com: add !pfn_valid_within() to check]
[minchan.kim@gmail.com: check end_pfn in pageblock_is_reserved]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This originally started as a simple patch to give vmalloc() some more
verbose output on failure on top of the plain page allocator messages.
Johannes suggested that it might be nicer to lead with the vmalloc() info
_before_ the page allocator messages.
But, I do think there's a lot of value in what __alloc_pages_slowpath()
does with its filtering and so forth.
This patch creates a new function which other allocators can call instead
of relying on the internal page allocator warnings. It also gives this
function private rate-limiting which separates it from other
printk_ratelimit() users.
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It's uncertain this has been beneficial, so it's safer to undo it. All
other compaction users would still go in synchronous mode if a first
attempt at async compaction failed. Hopefully we don't need to force
special behavior for THP (which is the only __GFP_NO_KSWAPD user so far
and it's the easier to exercise and to be noticeable). This also make
__GFP_NO_KSWAPD return to its original strict semantics specific to bypass
kswapd, as THP allocations have khugepaged for the async THP
allocations/compactions.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Alex Villacis Lasso <avillaci@fiec.espol.edu.ec>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, memory hotplug calls setup_per_zone_wmarks() and
calculate_zone_inactive_ratio(), but doesn't call
setup_per_zone_lowmem_reserve().
It means the number of reserved pages aren't updated even if memory hot
plug occur. This patch fixes it.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit bce7394a3e ("page-allocator: reset wmark_min and inactive ratio of
zone when hotplug happens") introduced invalid section references. Now,
setup_per_zone_inactive_ratio() is marked __init and then it can't be
referenced from memory hotplug code.
This patch marks it as __meminit and also marks caller as __ref.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Architectures that implement their own show_mem() function did not pass
the filter argument to show_free_areas() to appropriately avoid emitting
the state of nodes that are disallowed in the current context. This patch
now passes the filter argument to show_free_areas() so those nodes are now
avoided.
This patch also removes the show_free_areas() wrapper around
__show_free_areas() and converts existing callers to pass an empty filter.
ia64 emits additional information for each node, so skip_free_areas_zone()
must be made global to filter disallowed nodes and it is converted to use
a nid argument rather than a zone for this use case.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Helge Deller <deller@gmx.de>
Cc: James Bottomley <jejb@parisc-linux.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
b43: fix comment typo reqest -> request
Haavard Skinnemoen has left Atmel
cris: typo in mach-fs Makefile
Kconfig: fix copy/paste-ism for dell-wmi-aio driver
doc: timers-howto: fix a typo ("unsgined")
perf: Only include annotate.h once in tools/perf/util/ui/browsers/annotate.c
md, raid5: Fix spelling error in comment ('Ofcourse' --> 'Of course').
treewide: fix a few typos in comments
regulator: change debug statement be consistent with the style of the rest
Revert "arm: mach-u300/gpio: Fix mem_region resource size miscalculations"
audit: acquire creds selectively to reduce atomic op overhead
rtlwifi: don't touch with treewide double semicolon removal
treewide: cleanup continuations and remove logging message whitespace
ath9k_hw: don't touch with treewide double semicolon removal
include/linux/leds-regulator.h: fix syntax in example code
tty: fix typo in descripton of tty_termios_encode_baud_rate
xtensa: remove obsolete BKL kernel option from defconfig
m68k: fix comment typo 'occcured'
arch:Kconfig.locks Remove unused config option.
treewide: remove extra semicolons
...
Commit e66eed651f ("list: remove prefetching from regular list
iterators") removed the include of prefetch.h from list.h, which
uncovered several cases that had apparently relied on that rather
obscure header file dependency.
So this fixes things up a bit, using
grep -L linux/prefetch.h $(git grep -l '[^a-z_]prefetchw*(' -- '*.[ch]')
grep -L 'prefetchw*(' $(git grep -l 'linux/prefetch.h' -- '*.[ch]')
to guide us in finding files that either need <linux/prefetch.h>
inclusion, or have it despite not needing it.
There are more of them around (mostly network drivers), but this gets
many core ones.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix new kernel-doc warning in mm/page_alloc.c:
Warning(mm/page_alloc.c:2370): No description found for parameter 'nid'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a alloc_pages_exact_nid() that allocates on a specific node.
The naming is quite broken, but fixing that would need a larger renaming
action.
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: tweak comment]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The memory hotplug case involves calling to build_all_zonelists() which
in turns calls in to setup_zone_pageset(). The latter is marked
__meminit while build_all_zonelists() itself has no particular
annotation. build_all_zonelists() is only handed a non-NULL pointer in
the case of memory hotplug through an existing __meminit path, so the
setup_zone_pageset() reference is always safe.
The options as such are either to flag build_all_zonelists() as __ref (as
per __build_all_zonelists()), or to simply discard the __meminit
annotation from setup_zone_pageset().
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
build_all_zonelists() which is not __meminit, calls setup_zone_pageset().
Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Commit ddd588b5dd ("oom: suppress nodes that are not allowed from
meminfo on oom kill") moved lib/show_mem.o out of lib/lib.a, which
resulted in build warnings on all architectures that implement their own
versions of show_mem():
lib/lib.a(show_mem.o): In function `show_mem':
show_mem.c:(.text+0x1f4): multiple definition of `show_mem'
arch/sparc/mm/built-in.o:(.text+0xd70): first defined here
The fix is to remove __show_mem() and add its argument to show_mem() in
all implementations to prevent this breakage.
Architectures that implement their own show_mem() actually don't do
anything with the argument yet, but they could be made to filter nodes
that aren't allowed in the current context in the future just like the
generic implementation.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: James Bottomley <James.Bottomley@hansenpartnership.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add checks at allocating or freeing a page whether the page is used (iow,
charged) from the view point of memcg.
This check may be useful in debugging a problem and we did similar checks
before the commit 52d4b9ac(memcg: allocate all page_cgroup at boot).
This patch adds some overheads at allocating or freeing memory, so it's
enabled only when CONFIG_DEBUG_VM is enabled.
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a new __GFP_OTHER_NODE flag to tell the low level numa statistics in
zone_statistics() that an allocation is on behalf of another thread. This
way the local and remote counters can be still correct, even when
background daemons like khugepaged are changing memory mappings.
This only affects the accounting, but I think it's worth doing that right
to avoid confusing users.
I first tried to just pass down the right node, but this required a lot of
changes to pass down this parameter and at least one addition of a 10th
argument to a 9 argument function. Using the flag is a lot less
intrusive.
Open: should be also used for migration?
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__GFP_NO_KSWAPD allocations are usually very expensive and not mandatory
to succeed as they have graceful fallback. Waiting for I/O in those,
tends to be overkill in terms of latencies, so we can reduce their latency
by disabling sync migrate.
Unfortunately, even with async migration it's still possible for the
process to be blocked waiting for a request slot (e.g. get_request_wait
in the block layer) when ->writepage is called. To prevent
__GFP_NO_KSWAPD blocking, this patch prevents ->writepage being called on
dirty page cache for asynchronous migration.
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=31142
[mel@csn.ul.ie: Avoid writebacks for NFS, retry locked pages, use bool]
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Arthur Marsh <arthur.marsh@internode.on.net>
Cc: Clemens Ladisch <cladisch@googlemail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Reported-by: Alex Villacis Lasso <avillaci@ceibo.fiec.espol.edu.ec>
Tested-by: Alex Villacis Lasso <avillaci@ceibo.fiec.espol.edu.ec>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
free_pcppages_bulk() frees pages from pcp lists in a round-robin fashion
by keeping batch_free counter. But it doesn't need to spin if there is
only one non-empty list. This can be checked by batch_free ==
MIGRATE_PCPTYPES.
[akpm@linux-foundation.org: fix comment]
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Displaying extremely verbose meminfo for all nodes on the system is
overkill for page allocation failures when the context restricts that
allocation to only a subset of nodes. We don't particularly care about
the state of all nodes when some are not allowed in the current context,
they can have an abundance of memory but we can't allocate from that part
of memory.
This patch suppresses disallowed nodes from the meminfo dump on a page
allocation failure if the context requires it.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When a page allocation failure occurs, show_mem() is called to dump the
state of the VM so users may understand what happened to get into that
condition.
This output, however, can be extremely verbose. In irq context, it may
result in significant delays that incur NMI watchdog timeouts when the
machine is large (we use CONFIG_NODES_SHIFT > 8 here to define a "large"
machine since the length of the show_mem() output is proportional to the
number of possible nodes).
This patch suppresses the show_mem() call in irq context when the kernel
has CONFIG_NODES_SHIFT > 8.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The oom killer is extremely verbose for machines with a large number of
cpus and/or nodes. This verbosity can often be harmful if it causes other
important messages to be scrolled from the kernel log and incurs a
signicant time delay, specifically for kernels with CONFIG_NODES_SHIFT >
8.
This patch causes only memory information to be displayed for nodes that
are allowed by current's cpuset when dumping the VM state. Information
for all other nodes is irrelevant to the oom condition; we don't care if
there's an abundance of memory elsewhere if we can't access it.
This only affects the behavior of dumping memory information when an oom
is triggered. Other dumps, such as for sysrq+m, still display the
unfiltered form when using the existing show_mem() interface.
Additionally, the per-cpu pageset statistics are extremely verbose in oom
killer output, so it is now suppressed. This removes
nodes_weight(current->mems_allowed) * (1 + nr_cpus)
lines from the oom killer output.
Callers may use __show_mem(SHOW_MEM_FILTER_NODES) to filter disallowed
nodes.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change the _mapcount value indicating PageBuddy from -2 to -128 for
more robusteness against page_mapcount() undeflows.
Use reset_page_mapcount instead of __ClearPageBuddy in bad_page to
ignore the previous retval of PageBuddy().
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Heiko found recent memblock change triggers these warnings on s390:
mm/page_alloc.c:3623:22: warning: 'last_active_region_index_in_nid' defined but not used
mm/page_alloc.c:3638:22: warning: 'previous_active_region_index_in_nid' defined but not used
Need to move those two function under HAVE_MEMBLOCK with its only
user, find_memory_core_early().
-tj: Minor updates to description.
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Now that bootmem.c and nobootmem.c are separate, there's no reason to
define __alloc_memory_core_early(), which is used only by nobootmem,
inside #ifdef in page_alloc.c. Move it to nobootmem.c and make it
static.
This patch doesn't introduce any behavior change.
-tj: Updated commit description.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Now that bootmem.c and nobootmem.c are separate, it's cleaner to
define contig_page_data in each file than in page_alloc.c with #ifdef.
Move it.
This patch doesn't introduce any behavior change.
-v2: According to Andrew, fixed the struct layout.
-tj: Updated commit description.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Conflicts:
arch/x86/mm/numa_64.c
Merge reason: fix the conflict, update to latest -rc and pick up this
dependent fix from Yinghai:
e6d2e2b2b1e1: memblock: don't adjust size in memblock_find_base()
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Commit 0e093d9976 ("writeback: do not sleep on the congestion queue if
there are no congested BDIs or if significant congestion is not being
encountered in the current zone") uncovered a livelock in the page
allocator that resulted in tasks infinitely looping trying to find
memory and kswapd running at 100% cpu.
The issue occurs because drain_all_pages() is called immediately
following direct reclaim when no memory is freed and try_to_free_pages()
returns non-zero because all zones in the zonelist do not have their
all_unreclaimable flag set.
When draining the per-cpu pagesets back to the buddy allocator for each
zone, the zone->pages_scanned counter is cleared to avoid erroneously
setting zone->all_unreclaimable later. The problem is that no pages may
actually be drained and, thus, the unreclaimable logic never fails
direct reclaim so the oom killer may be invoked.
This apparently only manifested after wait_iff_congested() was
introduced and the zone was full of anonymous memory that would not
congest the backing store. The page allocator would infinitely loop if
there were no other tasks waiting to be scheduled and clear
zone->pages_scanned because of drain_all_pages() as the result of this
change before kswapd could scan enough pages to trigger the reclaim
logic. Additionally, with every loop of the page allocator and in the
reclaim path, kswapd would be kicked and would end up running at 100%
cpu. In this scenario, current and kswapd are all running continuously
with kswapd incrementing zone->pages_scanned and current clearing it.
The problem is even more pronounced when current swaps some of its
memory to swap cache and the reclaimable logic then considers all active
anonymous memory in the all_unreclaimable logic, which requires a much
higher zone->pages_scanned value for try_to_free_pages() to return zero
that is never attainable in this scenario.
Before wait_iff_congested(), the page allocator would incur an
unconditional timeout and allow kswapd to elevate zone->pages_scanned to
a level that the oom killer would be called the next time it loops.
The fix is to only attempt to drain pcp pages if there is actually a
quantity to be drained. The unconditional clearing of
zone->pages_scanned in free_pcppages_bulk() need not be changed since
other callers already ensure that draining will occur. This patch
ensures that free_pcppages_bulk() will actually free memory before
calling into it from drain_all_pages() so zone->pages_scanned is only
cleared if appropriate.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Before 0e093d9976 ("writeback: do not sleep on the congestion queue if
there are no congested BDIs or if significant congestion is not being
encountered in the current zone"), preferred_zone was only used for NUMA
statistics, to determine the zoneidx from which to allocate from given
the type requested, and whether to utilize memory compaction.
wait_iff_congested(), though, uses preferred_zone to determine if the
congestion wait should be deferred because its dirty pages are backed by
a congested bdi. This incorrectly defers the timeout and busy loops in
the page allocator with various cond_resched() calls if preferred_zone
is not allowed in the current context, usually consuming 100% of a cpu.
This patch ensures preferred_zone is an allowed zone in the fastpath
depending on whether current is constrained by its cpuset or nodes in
its mempolicy (when the nodemask passed is non-NULL). This is correct
since the fastpath allocation always passes ALLOC_CPUSET when trying to
allocate memory. In the slowpath, this patch resets preferred_zone to
the first zone of the allowed type when the allocation is not
constrained by current's cpuset, i.e. it does not pass ALLOC_CPUSET.
This patch also ensures preferred_zone is from the set of allowed nodes
when called from within direct reclaim since allocations are always
constrained by cpusets in this context (it is blockable).
Both of these uses of cpuset_current_mems_allowed are protected by
get_mems_allowed().
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The previous approach of calucation of combined index was
page_idx & ~(1 << order))
but we have same result with
page_idx & buddy_idx
This reduces instructions slightly as well as enhances readability.
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix used-unintialised warning]
Signed-off-by: KyongHo Cho <pullip.cho@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
PG_buddy can be converted to _mapcount == -2. So the PG_compound_lock can
be added to page->flags without overflowing (because of the sparse section
bits increasing) with CONFIG_X86_PAE=y and CONFIG_X86_PAT=y. This also
has to move the memory hotplug code from _mapcount to lru.next to avoid
any risk of clashes. We can't use lru.next for PG_buddy removal, but
memory hotplug can use lru.next even more easily than the mapcount
instead.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Not worth throwing away the precious reserved free memory pool for
allocations that can fail gracefully (either through mempool or because
they're transhuge allocations later falling back to 4k allocations).
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Transparent hugepage allocations must be allowed not to invoke kswapd or
any other kind of indirect reclaim (especially when the defrag sysfs is
control disabled). It's unacceptable to swap out anonymous pages
(potentially anonymous transparent hugepages) in order to create new
transparent hugepages. This is true for the MADV_HUGEPAGE areas too
(swapping out a kvm virtual machine and so having it suffer an unbearable
slowdown, so another one with guest physical memory marked MADV_HUGEPAGE
can run 30% faster if it is running memory intensive workloads, makes no
sense). If a transparent hugepage allocation fails the slowdown is minor
and there is total fallback, so kswapd should never be asked to swapout
memory to allow the high order allocation to succeed.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Warn destroy_compound_page that __split_huge_page_refcount is heavily
dependent on its internal behavior.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Clear compound mapping for anonymous compound pages like it already
happens for regular anonymous pages. But crash if mapping is set for any
tail page, also the PageAnon check is meaningless for tail pages. This
check only makes sense for the head page, for tail page it can only hide
bugs and we definitely don't want to hide bugs.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
page_count shows the count of the head page, but the actual check is done
on the tail page, so show what is really being checked.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When numa_zonelist_order parameter is set to "node" or "zone" on the
command line it's still showing as "default" in sysctl. That's because
early_param parsing function changes only user_zonelist_order variable.
Fix this by copying user-provided string to numa_zonelist_order if it was
successfully parsed.
Signed-off-by: Volodymyr G Lukiianyk <volodymyrgl@gmail.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Simon Kirby reported the following problem
We're seeing cases on a number of servers where cache never fully
grows to use all available memory. Sometimes we see servers with 4 GB
of memory that never seem to have less than 1.5 GB free, even with a
constantly-active VM. In some cases, these servers also swap out while
this happens, even though they are constantly reading the working set
into memory. We have been seeing this happening for a long time; I
don't think it's anything recent, and it still happens on 2.6.36.
After some debugging work by Simon, Dave Hansen and others, the prevaling
theory became that kswapd is reclaiming order-3 pages requested by SLUB
too aggressive about it.
There are two apparent problems here. On the target machine, there is a
small Normal zone in comparison to DMA32. As kswapd tries to balance all
zones, it would continually try reclaiming for Normal even though DMA32
was balanced enough for callers. The second problem is that
sleeping_prematurely() does not use the same logic as balance_pgdat() when
deciding whether to sleep or not. This keeps kswapd artifically awake.
A number of tests were run and the figures from previous postings will
look very different for a few reasons. One, the old figures were forcing
my network card to use GFP_ATOMIC in attempt to replicate Simon's problem.
Second, I previous specified slub_min_order=3 again in an attempt to
reproduce Simon's problem. In this posting, I'm depending on Simon to say
whether his problem is fixed or not and these figures are to show the
impact to the ordinary cases. Finally, the "vmscan" figures are taken
from /proc/vmstat instead of the tracepoints. There is less information
but recording is less disruptive.
The first test of relevance was postmark with a process running in the
background reading a large amount of anonymous memory in blocks. The
objective was to vaguely simulate what was happening on Simon's machine
and it's memory intensive enough to have kswapd awake.
POSTMARK
traceonly kanyzone
Transactions per second: 156.00 ( 0.00%) 153.00 (-1.96%)
Data megabytes read per second: 21.51 ( 0.00%) 21.52 ( 0.05%)
Data megabytes written per second: 29.28 ( 0.00%) 29.11 (-0.58%)
Files created alone per second: 250.00 ( 0.00%) 416.00 (39.90%)
Files create/transact per second: 79.00 ( 0.00%) 76.00 (-3.95%)
Files deleted alone per second: 520.00 ( 0.00%) 420.00 (-23.81%)
Files delete/transact per second: 79.00 ( 0.00%) 76.00 (-3.95%)
MMTests Statistics: duration
User/Sys Time Running Test (seconds) 16.58 17.4
Total Elapsed Time (seconds) 218.48 222.47
VMstat Reclaim Statistics: vmscan
Direct reclaims 0 4
Direct reclaim pages scanned 0 203
Direct reclaim pages reclaimed 0 184
Kswapd pages scanned 326631 322018
Kswapd pages reclaimed 312632 309784
Kswapd low wmark quickly 1 4
Kswapd high wmark quickly 122 475
Kswapd skip congestion_wait 1 0
Pages activated 700040 705317
Pages deactivated 212113 203922
Pages written 9875 6363
Total pages scanned 326631 322221
Total pages reclaimed 312632 309968
%age total pages scanned/reclaimed 95.71% 96.20%
%age total pages scanned/written 3.02% 1.97%
proc vmstat: Faults
Major Faults 300 254
Minor Faults 645183 660284
Page ins 493588 486704
Page outs 4960088 4986704
Swap ins 1230 661
Swap outs 9869 6355
Performance is mildly affected because kswapd is no longer doing as much
work and the background memory consumer process is getting in the way.
Note that kswapd scanned and reclaimed fewer pages as it's less aggressive
and overall fewer pages were scanned and reclaimed. Swap in/out is
particularly reduced again reflecting kswapd throwing out fewer pages.
The slight performance impact is unfortunate here but it looks like a
direct result of kswapd being less aggressive. As the bug report is about
too many pages being freed by kswapd, it may have to be accepted for now.
The second test is a streaming IO benchmark that was previously used by
Johannes to show regressions in page reclaim.
MICRO
traceonly kanyzone
User/Sys Time Running Test (seconds) 29.29 28.87
Total Elapsed Time (seconds) 492.18 488.79
VMstat Reclaim Statistics: vmscan
Direct reclaims 2128 1460
Direct reclaim pages scanned 2284822 1496067
Direct reclaim pages reclaimed 148919 110937
Kswapd pages scanned 15450014 16202876
Kswapd pages reclaimed 8503697 8537897
Kswapd low wmark quickly 3100 3397
Kswapd high wmark quickly 1860 7243
Kswapd skip congestion_wait 708 801
Pages activated 9635 9573
Pages deactivated 1432 1271
Pages written 223 1130
Total pages scanned 17734836 17698943
Total pages reclaimed 8652616 8648834
%age total pages scanned/reclaimed 48.79% 48.87%
%age total pages scanned/written 0.00% 0.01%
proc vmstat: Faults
Major Faults 165 221
Minor Faults 9655785 9656506
Page ins 3880 7228
Page outs 37692940 37480076
Swap ins 0 69
Swap outs 19 15
Again fewer pages are scanned and reclaimed as expected and this time the
test completed faster. Note that kswapd is hitting its watermarks faster
(low and high wmark quickly) which I expect is due to kswapd reclaiming
fewer pages.
I also ran fs-mark, iozone and sysbench but there is nothing interesting
to report in the figures. Performance is not significantly changed and
the reclaim statistics look reasonable.
Tgis patch:
When the allocator enters its slow path, kswapd is woken up to balance the
node. It continues working until all zones within the node are balanced.
For order-0 allocations, this makes perfect sense but for higher orders it
can have unintended side-effects. If the zone sizes are imbalanced,
kswapd may reclaim heavily within a smaller zone discarding an excessive
number of pages. The user-visible behaviour is that kswapd is awake and
reclaiming even though plenty of pages are free from a suitable zone.
This patch alters the "balance" logic for high-order reclaim allowing
kswapd to stop if any suitable zone becomes balanced to reduce the number
of pages it reclaims from other zones. kswapd still tries to ensure that
order-0 watermarks for all zones are met before sleeping.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Eric B Munson <emunson@mgebm.net>
Cc: Simon Kirby <sim@hostway.ca>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Migration synchronously waits for writeback if the initial passes fails.
Callers of memory compaction do not necessarily want this behaviour if the
caller is latency sensitive or expects that synchronous migration is not
going to have a significantly better success rate.
This patch adds a sync parameter to migrate_pages() allowing the caller to
indicate if wait_on_page_writeback() is allowed within migration or not.
For reclaim/compaction, try_to_compact_pages() is first called
asynchronously, direct reclaim runs and then try_to_compact_pages() is
called synchronously as there is a greater expectation that it'll succeed.
[akpm@linux-foundation.org: build/merge fix]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lumpy reclaim is disruptive. It reclaims a large number of pages and
ignores the age of the pages it reclaims. This can incur significant
stalls and potentially increase the number of major faults.
Compaction has reached the point where it is considered reasonably stable
(meaning it has passed a lot of testing) and is a potential candidate for
displacing lumpy reclaim. This patch introduces an alternative to lumpy
reclaim whe compaction is available called reclaim/compaction. The basic
operation is very simple - instead of selecting a contiguous range of
pages to reclaim, a number of order-0 pages are reclaimed and then
compaction is later by either kswapd (compact_zone_order()) or direct
compaction (__alloc_pages_direct_compact()).
[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: use conventional task_struct naming]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit aa45484 ("calculate a better estimate of NR_FREE_PAGES when memory
is low") noted that watermarks were based on the vmstat NR_FREE_PAGES. To
avoid synchronization overhead, these counters are maintained on a per-cpu
basis and drained both periodically and when a threshold is above a
threshold. On large CPU systems, the difference between the estimate and
real value of NR_FREE_PAGES can be very high. The system can get into a
case where pages are allocated far below the min watermark potentially
causing livelock issues. The commit solved the problem by taking a better
reading of NR_FREE_PAGES when memory was low.
Unfortately, as reported by Shaohua Li this accurate reading can consume a
large amount of CPU time on systems with many sockets due to cache line
bouncing. This patch takes a different approach. For large machines
where counter drift might be unsafe and while kswapd is awake, the per-cpu
thresholds for the target pgdat are reduced to limit the level of drift to
what should be a safe level. This incurs a performance penalty in heavy
memory pressure by a factor that depends on the workload and the machine
but the machine should function correctly without accidentally exhausting
all memory on a node. There is an additional cost when kswapd wakes and
sleeps but the event is not expected to be frequent - in Shaohua's test
case, there was one recorded sleep and wake event at least.
To ensure that kswapd wakes up, a safe version of zone_watermark_ok() is
introduced that takes a more accurate reading of NR_FREE_PAGES when called
from wakeup_kswapd, when deciding whether it is really safe to go back to
sleep in sleeping_prematurely() and when deciding if a zone is really
balanced or not in balance_pgdat(). We are still using an expensive
function but limiting how often it is called.
When the test case is reproduced, the time spent in the watermark
functions is reduced. The following report is on the percentage of time
spent cumulatively spent in the functions zone_nr_free_pages(),
zone_watermark_ok(), __zone_watermark_ok(), zone_watermark_ok_safe(),
zone_page_state_snapshot(), zone_page_state().
vanilla 11.6615%
disable-threshold 0.2584%
David said:
: We had to pull aa454840 "mm: page allocator: calculate a better estimate
: of NR_FREE_PAGES when memory is low and kswapd is awake" from 2.6.36
: internally because tests showed that it would cause the machine to stall
: as the result of heavy kswapd activity. I merged it back with this fix as
: it is pending in the -mm tree and it solves the issue we were seeing, so I
: definitely think this should be pushed to -stable (and I would seriously
: consider it for 2.6.37 inclusion even at this late date).
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reported-by: Shaohua Li <shaohua.li@intel.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Tested-by: Nicolas Bareil <nico@chdir.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: <stable@kernel.org> [2.6.37.1, 2.6.36.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
That is used for find ram in node or bootmem type.
We should make it top-down so it will be consistent to memblock_find,
and to avoid allocating potentially valuable low memory before we
actually need it.
Suggested-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4D0C075B.3040501@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Conflicts:
MAINTAINERS
arch/arm/mach-omap2/pm24xx.c
drivers/scsi/bfa/bfa_fcpim.c
Needed to update to apply fixes for which the old branch was too
outdated.
There is a problem that swap pages allocated before the creation of
a hibernation image can be released and used for storing the contents
of different memory pages while the image is being saved. Since the
kernel stored in the image doesn't know of that, it causes memory
corruption to occur after resume from hibernation, especially on
systems with relatively small RAM that need to swap often.
This issue can be addressed by keeping the GFP_IOFS bits clear
in gfp_allowed_mask during the entire hibernation, including the
saving of the image, until the system is finally turned off or
the hibernation is aborted. Unfortunately, for this purpose
it's necessary to rework the way in which the hibernate and
suspend code manipulates gfp_allowed_mask.
This change is based on an earlier patch from Hugh Dickins.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Ondrej Zary <linux@rainbow-software.org>
Acked-by: Hugh Dickins <hughd@google.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: stable@kernel.org
These warnings are spewed during a build of a 'allnoconfig' kernel
(especially the ones from u64_stats_sync.h show up a lot) when building
with -Wextra (which I often do)..
They are
a) annoying
b) easy to get rid of.
This patch kills them off.
include/linux/u64_stats_sync.h:70:1: warning: ‘inline’ is not at beginning of declaration
include/linux/u64_stats_sync.h:77:1: warning: ‘inline’ is not at beginning of declaration
include/linux/u64_stats_sync.h:84:1: warning: ‘inline’ is not at beginning of declaration
include/linux/u64_stats_sync.h:96:1: warning: ‘inline’ is not at beginning of declaration
include/linux/u64_stats_sync.h:115:1: warning: ‘inline’ is not at beginning of declaration
include/linux/u64_stats_sync.h:127:1: warning: ‘inline’ is not at beginning of declaration
kernel/time.c:241:1: warning: ‘inline’ is not at beginning of declaration
kernel/time.c:257:1: warning: ‘inline’ is not at beginning of declaration
kernel/perf_event.c:4513:1: warning: ‘inline’ is not at beginning of declaration
mm/page_alloc.c:4012:1: warning: ‘inline’ is not at beginning of declaration
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
During memory hotplug, build_allzonelists() may be called under
stop_machine_run(). In this function, setup_zone_pageset() is called.
But it's bug because it will do page allocation under stop_machine_run().
Here is a report from Alok Kataria.
BUG: sleeping function called from invalid context at kernel/mutex.c:94
in_atomic(): 0, irqs_disabled(): 1, pid: 4, name: migration/0
Pid: 4, comm: migration/0 Not tainted 2.6.35.6-45.fc14.x86_64 #1
Call Trace:
[<ffffffff8103d12b>] __might_sleep+0xeb/0xf0
[<ffffffff81468245>] mutex_lock+0x24/0x50
[<ffffffff8110eaa6>] pcpu_alloc+0x6d/0x7ee
[<ffffffff81048888>] ? load_balance+0xbe/0x60e
[<ffffffff8103a1b3>] ? rt_se_boosted+0x21/0x2f
[<ffffffff8103e1cf>] ? dequeue_rt_stack+0x18b/0x1ed
[<ffffffff8110f237>] __alloc_percpu+0x10/0x12
[<ffffffff81465e22>] setup_zone_pageset+0x38/0xbe
[<ffffffff810d6d81>] ? build_zonelists_node.clone.58+0x79/0x8c
[<ffffffff81452539>] __build_all_zonelists+0x419/0x46c
[<ffffffff8108ef01>] ? cpu_stopper_thread+0xb2/0x198
[<ffffffff8108f075>] stop_machine_cpu_stop+0x8e/0xc5
[<ffffffff8108efe7>] ? stop_machine_cpu_stop+0x0/0xc5
[<ffffffff8108ef57>] cpu_stopper_thread+0x108/0x198
[<ffffffff81467a37>] ? schedule+0x5b2/0x5cc
[<ffffffff8108ee4f>] ? cpu_stopper_thread+0x0/0x198
[<ffffffff81065f29>] kthread+0x7f/0x87
[<ffffffff8100aae4>] kernel_thread_helper+0x4/0x10
[<ffffffff81065eaa>] ? kthread+0x0/0x87
[<ffffffff8100aae0>] ? kernel_thread_helper+0x0/0x10
Built 5 zonelists in Node order, mobility grouping on. Total pages: 289456
Policy zone: Normal
This patch tries to fix the issue by moving setup_zone_pageset() out from
stop_machine_run(). It's obviously not necessary to be called under
stop_machine_run().
[akpm@linux-foundation.org: remove unneeded local]
Reported-by: Alok Kataria <akataria@vmware.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Petr Vandrovec <petr@vmware.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This removes following warning from sparse:
mm/page_alloc.c:1934:9: warning: restricted gfp_t degrades to integer
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If congestion_wait() is called with no BDI congested, the caller will
sleep for the full timeout and this may be an unnecessary sleep. This
patch adds a wait_iff_congested() that checks congestion and only sleeps
if a BDI is congested else, it calls cond_resched() to ensure the caller
is not hogging the CPU longer than its quota but otherwise will not sleep.
This is aimed at reducing some of the major desktop stalls reported during
IO. For example, while kswapd is operating, it calls congestion_wait()
but it could just have been reclaiming clean page cache pages with no
congestion. Without this patch, it would sleep for a full timeout but
after this patch, it'll just call schedule() if it has been on the CPU too
long. Similar logic applies to direct reclaimers that are not making
enough progress.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now, sysfs interface of memory hotplug shows whether the section is
removable or not. But it checks only migrateype of pages and doesn't
check details of cluster of pages.
Next, memory hotplug's set_migratetype_isolate() has the same kind of
check, too.
This patch adds the function __count_unmovable_pages() and makes above 2
checks to use the same logic. Then, is_removable and hotremove code uses
the same logic. No changes in the hotremove logic itself.
TODO: need to find a way to check RECLAMABLE. But, considering bit,
calling shrink_slab() against a range before starting memory hotremove
sounds better. If so, this patch's logic doesn't need to be changed.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reported-by: Michal Hocko <mhocko@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Even if notifier cannot find any pages, it doesn't mean no pages are
available...And, if there are no notifiers registered, this condition will
be always true and memory hotplug will show -EBUSY.
This is a bug but not critical.
In most case, a pageblock which will be offlined is MIGRATE_MOVABLE This
"notifier" is called only when the pageblock is _not_ MIGRATE_MOVABLE.
But if not MIGRATE_MOVABLE, it's common case that memory hotplug will
fail. So, no one notice this bug.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a bug in commit 6dda9d55 ("page allocator: reduce fragmentation
in buddy allocator by adding buddies that are merging to the tail of the
free lists") that means a buddy at order MAX_ORDER is checked for merging.
A page of this order never exists so at times, an effectively random
piece of memory is being checked.
Alan Curry has reported that this is causing memory corruption in
userspace data on a PPC32 platform (http://lkml.org/lkml/2010/10/9/32).
It is not clear why this is happening. It could be a cache coherency
problem where pages mapped in both user and kernel space are getting
different cache lines due to the bad read from kernel space
(http://lkml.org/lkml/2010/10/13/179). It could also be that there are
some special registers being io-remapped at the end of the memmap array
and that a read has special meaning on them. Compiler bugs have been
ruled out because the assembly before and after the patch looks relatively
harmless.
This patch fixes the problem by ensuring we are not reading a possibly
invalid location of memory. It's not clear why the read causes corruption
but one way or the other it is a buggy read.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Corrado Zoccolo <czoccolo@gmail.com>
Reported-by: Alan Curry <pacman@kosh.dhis.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reason for merge:
Forward-port urgent change to arch/x86/mm/srat_64.c to the memblock tree.
Resolved Conflicts:
arch/x86/mm/srat_64.c
Originally-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
During boot of a 16TB system, the following is printed:
Dentry cache hash table entries: -2147483648 (order: 22, 17179869184 bytes)
Signed-off-by: Robin Holt <holt@sgi.com>
Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When under significant memory pressure, a process enters direct reclaim
and immediately afterwards tries to allocate a page. If it fails and no
further progress is made, it's possible the system will go OOM. However,
on systems with large amounts of memory, it's possible that a significant
number of pages are on per-cpu lists and inaccessible to the calling
process. This leads to a process entering direct reclaim more often than
it should increasing the pressure on the system and compounding the
problem.
This patch notes that if direct reclaim is making progress but allocations
are still failing that the system is already under heavy pressure. In
this case, it drains the per-cpu lists and tries the allocation a second
time before continuing.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ordinarily watermark checks are based on the vmstat NR_FREE_PAGES as it is
cheaper than scanning a number of lists. To avoid synchronization
overhead, counter deltas are maintained on a per-cpu basis and drained
both periodically and when the delta is above a threshold. On large CPU
systems, the difference between the estimated and real value of
NR_FREE_PAGES can be very high. If NR_FREE_PAGES is much higher than
number of real free page in buddy, the VM can allocate pages below min
watermark, at worst reducing the real number of pages to zero. Even if
the OOM killer kills some victim for freeing memory, it may not free
memory if the exit path requires a new page resulting in livelock.
This patch introduces a zone_page_state_snapshot() function (courtesy of
Christoph) that takes a slightly more accurate view of an arbitrary vmstat
counter. It is used to read NR_FREE_PAGES while kswapd is awake to avoid
the watermark being accidentally broken. The estimate is not perfect and
may result in cache line bounces but is expected to be lighter than the
IPI calls necessary to continually drain the per-cpu counters while kswapd
is awake.
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When allocating a page, the system uses NR_FREE_PAGES counters to
determine if watermarks would remain intact after the allocation was made.
This check is made without interrupts disabled or the zone lock held and
so is race-prone by nature. Unfortunately, when pages are being freed in
batch, the counters are updated before the pages are added on the list.
During this window, the counters are misleading as the pages do not exist
yet. When under significant pressure on systems with large numbers of
CPUs, it's possible for processes to make progress even though they should
have been stalled. This is particularly problematic if a number of the
processes are using GFP_ATOMIC as the min watermark can be accidentally
breached and in extreme cases, the system can livelock.
This patch updates the counters after the pages have been added to the
list. This makes the allocator more cautious with respect to preserving
the watermarks and mitigates livelock possibilities.
[akpm@linux-foundation.org: avoid modifying incoming args]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1. replace find_e820_area with memblock_find_in_range
2. replace reserve_early with memblock_x86_reserve_range
3. replace free_early with memblock_x86_free_range.
4. NO_BOOTMEM will switch to use memblock too.
5. use _e820, _early wrap in the patch, in following patch, will
replace them all
6. because memblock_x86_free_range support partial free, we can remove some special care
7. Need to make sure that memblock_find_in_range() is called after memblock_x86_fill()
so adjust some calling later in setup.c::setup_arch()
-- corruption_check and mptable_update
-v2: Move reserve_brk() early
Before fill_memblock_area, to avoid overlap between brk and memblock_find_in_range()
that could happen We have more then 128 RAM entry in E820 tables, and
memblock_x86_fill() could use memblock_find_in_range() to find a new place for
memblock.memory.region array.
and We don't need to use extend_brk() after fill_memblock_area()
So move reserve_brk() early before fill_memblock_area().
-v3: Move find_smp_config early
To make sure memblock_find_in_range not find wrong place, if BIOS doesn't put mptable
in right place.
-v4: Treat RESERVED_KERN as RAM in memblock.memory. and they are already in
memblock.reserved already..
use __NOT_KEEP_MEMBLOCK to make sure memblock related code could be freed later.
-v5: Generic version __memblock_find_in_range() is going from high to low, and for 32bit
active_region for 32bit does include high pages
need to replace the limit with memblock.default_alloc_limit, aka get_max_mapped()
-v6: Use current_limit instead
-v7: check with MEMBLOCK_ERROR instead of -1ULL or -1L
-v8: Set memblock_can_resize early to handle EFI with more RAM entries
-v9: update after kmemleak changes in mainline
Suggested-by: David S. Miller <davem@davemloft.net>
Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
According to node range in early_node_map[] with __memblock_find_in_range
to find free range.
Will be used by memblock_x86_find_in_range_node()
memblock_x86_find_in_range_node will be used to find right buffer for NODE_DATA
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Since 2.6.28 zone->prev_priority is unused. Then it can be removed
safely. It reduce stack usage slightly.
Now I have to say that I'm sorry. 2 years ago, I thought prev_priority
can be integrate again, it's useful. but four (or more) times trying
haven't got good performance number. Thus I give up such approach.
The rest of this changelog is notes on prev_priority and why it existed in
the first place and why it might be not necessary any more. This information
is based heavily on discussions between Andrew Morton, Rik van Riel and
Kosaki Motohiro who is heavily quotes from.
Historically prev_priority was important because it determined when the VM
would start unmapping PTE pages. i.e. there are no balances of note within
the VM, Anon vs File and Mapped vs Unmapped. Without prev_priority, there
is a potential risk of unnecessarily increasing minor faults as a large
amount of read activity of use-once pages could push mapped pages to the
end of the LRU and get unmapped.
There is no proof this is still a problem but currently it is not considered
to be. Active files are not deactivated if the active file list is smaller
than the inactive list reducing the liklihood that file-mapped pages are
being pushed off the LRU and referenced executable pages are kept on the
active list to avoid them getting pushed out by read activity.
Even if it is a problem, prev_priority prev_priority wouldn't works
nowadays. First of all, current vmscan still a lot of UP centric code. it
expose some weakness on some dozens CPUs machine. I think we need more and
more improvement.
The problem is, current vmscan mix up per-system-pressure, per-zone-pressure
and per-task-pressure a bit. example, prev_priority try to boost priority to
other concurrent priority. but if the another task have mempolicy restriction,
it is unnecessary, but also makes wrong big latency and exceeding reclaim.
per-task based priority + prev_priority adjustment make the emulation of
per-system pressure. but it have two issue 1) too rough and brutal emulation
2) we need per-zone pressure, not per-system.
Another example, currently DEF_PRIORITY is 12. it mean the lru rotate about
2 cycle (1/4096 + 1/2048 + 1/1024 + .. + 1) before invoking OOM-Killer.
but if 10,0000 thrreads enter DEF_PRIORITY reclaim at the same time, the
system have higher memory pressure than priority==0 (1/4096*10,000 > 2).
prev_priority can't solve such multithreads workload issue. In other word,
prev_priority concept assume the sysmtem don't have lots threads."
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michael Rubin <mrubin@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We have been used naming try_set_zone_oom and clear_zonelist_oom.
The role of functions is to lock of zonelist for preventing parallel
OOM. So clear_zonelist_oom makes sense but try_set_zone_oome is rather
awkward and unmatched with clear_zonelist_oom.
Let's change it with try_set_zonelist_oom.
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If memory has been depleted in lowmem zones even with the protection
afforded to it by /proc/sys/vm/lowmem_reserve_ratio, it is unlikely that
killing current users will help. The memory is either reclaimable (or
migratable) already, in which case we should not invoke the oom killer at
all, or it is pinned by an application for I/O. Killing such an
application may leave the hardware in an unspecified state and there is no
guarantee that it will be able to make a timely exit.
Lowmem allocations are now failed in oom conditions when __GFP_NOFAIL is
not used so that the task can perhaps recover or try again later.
Previously, the heuristic provided some protection for those tasks with
CAP_SYS_RAWIO, but this is no longer necessary since we will not be
killing tasks for the purposes of ISA allocations.
high_zoneidx is gfp_zone(gfp_flags), meaning that ZONE_NORMAL will be the
default for all allocations that are not __GFP_DMA, __GFP_DMA32,
__GFP_HIGHMEM, and __GFP_MOVABLE on kernels configured to support those
flags. Testing for high_zoneidx being less than ZONE_NORMAL will only
return true for allocations that have either __GFP_DMA or __GFP_DMA32.
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With commits 08677214 and 59be5a8e, alloc_bootmem()/free_bootmem() and
friends use the early_res functions for memory management when
NO_BOOTMEM is enabled. This patch adds the kmemleak calls in the
corresponding code paths for bootmem allocations.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: stable@kernel.org
Introduce numa_mem_id(), based on generic percpu variable infrastructure
to track "nearest node with memory" for archs that support memoryless
nodes.
Define API in <linux/topology.h> when CONFIG_HAVE_MEMORYLESS_NODES
defined, else stubs. Architectures will define HAVE_MEMORYLESS_NODES
if/when they support them.
Archs can override definitions of:
numa_mem_id() - returns node number of "local memory" node
set_numa_mem() - initialize [this cpus'] per cpu variable 'numa_mem'
cpu_to_mem() - return numa_mem for specified cpu; may be used as lvalue
Generic initialization of 'numa_mem' occurs in __build_all_zonelists().
This will initialize the boot cpu at boot time, and all cpus on change of
numa_zonelist_order, or when node or memory hot-plug requires zonelist
rebuild. Archs that support memoryless nodes will need to initialize
'numa_mem' for secondary cpus as they're brought on-line.
[akpm@linux-foundation.org: fix build]
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Nick Piggin <npiggin@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Eric Whitney <eric.whitney@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rework the generic version of the numa_node_id() function to use the new
generic percpu variable infrastructure.
Guard the new implementation with a new config option:
CONFIG_USE_PERCPU_NUMA_NODE_ID.
Archs which support this new implemention will default this option to 'y'
when NUMA is configured. This config option could be removed if/when all
archs switch over to the generic percpu implementation of numa_node_id().
Arch support involves:
1) converting any existing per cpu variable implementations to use
this implementation. x86_64 is an instance of such an arch.
2) archs that don't use a per cpu variable for numa_node_id() will
need to initialize the new per cpu variable "numa_node" as cpus
are brought on-line. ia64 is an example.
3) Defining USE_PERCPU_NUMA_NODE_ID in arch dependent Kconfig--e.g.,
when NUMA is configured. This is required because I have
retained the old implementation by default to allow archs to
be modified incrementally, as desired.
Subsequent patches will convert x86_64 and ia64 to use this implemenation.
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Nick Piggin <npiggin@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Eric Whitney <eric.whitney@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add global mutex zonelists_mutex to fix the possible race:
CPU0 CPU1 CPU2
(1) zone->present_pages += online_pages;
(2) build_all_zonelists();
(3) alloc_page();
(4) free_page();
(5) build_all_zonelists();
(6) __build_all_zonelists();
(7) zone->pageset = alloc_percpu();
In step (3,4), zone->pageset still points to boot_pageset, so bad
things may happen if 2+ nodes are in this state. Even if only 1 node
is accessing the boot_pageset, (3) may still consume too much memory
to fail the memory allocations in step (7).
Besides, atomic operation ensures alloc_percpu() in step (7) will never fail
since there is a new fresh memory block added in step(6).
[haicheng.li@linux.intel.com: hold zonelists_mutex when build_all_zonelists]
Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Andi Kleen <andi.kleen@intel.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For each new populated zone of hotadded node, need to update its pagesets
with dynamically allocated per_cpu_pageset struct for all possible CPUs:
1) Detach zone->pageset from the shared boot_pageset
at end of __build_all_zonelists().
2) Use mutex to protect zone->pageset when it's still
shared in onlined_pages()
Otherwises, multiple zones of different nodes would share same boot strapping
boot_pageset for same CPU, which will finally cause below kernel panic:
------------[ cut here ]------------
kernel BUG at mm/page_alloc.c:1239!
invalid opcode: 0000 [#1] SMP
...
Call Trace:
[<ffffffff811300c1>] __alloc_pages_nodemask+0x131/0x7b0
[<ffffffff81162e67>] alloc_pages_current+0x87/0xd0
[<ffffffff81128407>] __page_cache_alloc+0x67/0x70
[<ffffffff811325f0>] __do_page_cache_readahead+0x120/0x260
[<ffffffff81132751>] ra_submit+0x21/0x30
[<ffffffff811329c6>] ondemand_readahead+0x166/0x2c0
[<ffffffff81132ba0>] page_cache_async_readahead+0x80/0xa0
[<ffffffff8112a0e4>] generic_file_aio_read+0x364/0x670
[<ffffffff81266cfa>] nfs_file_read+0xca/0x130
[<ffffffff8117b20a>] do_sync_read+0xfa/0x140
[<ffffffff8117bf75>] vfs_read+0xb5/0x1a0
[<ffffffff8117c151>] sys_read+0x51/0x80
[<ffffffff8103c032>] system_call_fastpath+0x16/0x1b
RIP [<ffffffff8112ff13>] get_page_from_freelist+0x883/0x900
RSP <ffff88000d1e78a8>
---[ end trace 4bda28328b9990db ]
[akpm@linux-foundation.org: merge fix]
Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Andi Kleen <andi.kleen@intel.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
No behavior change here.
Move some of setup_per_cpu_pageset() code into a new function
setup_zone_pageset() that will be useful for memory hotplug.
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com>
Reviewed-by: Andi Kleen <andi.kleen@intel.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The fragmentation index may indicate that a failure is due to external
fragmentation but after a compaction run completes, it is still possible
for an allocation to fail. There are two obvious reasons as to why
o Page migration cannot move all pages so fragmentation remains
o A suitable page may exist but watermarks are not met
In the event of compaction followed by an allocation failure, this patch
defers further compaction in the zone (1 << compact_defer_shift) times.
If the next compaction attempt also fails, compact_defer_shift is
increased up to a maximum of 6. If compaction succeeds, the defer
counters are reset again.
The zone that is deferred is the first zone in the zonelist - i.e. the
preferred zone. To defer compaction in the other zones, the information
would need to be stored in the zonelist or implemented similar to the
zonelist_cache. This would impact the fast-paths and is not justified at
this time.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ordinarily when a high-order allocation fails, direct reclaim is entered
to free pages to satisfy the allocation. With this patch, it is
determined if an allocation failed due to external fragmentation instead
of low memory and if so, the calling process will compact until a suitable
page is freed. Compaction by moving pages in memory is considerably
cheaper than paging out to disk and works where there are locked pages or
no swap. If compaction fails to free a page of a suitable size, then
reclaim will still occur.
Direct compaction returns as soon as possible. As each block is
compacted, it is checked if a suitable page has been freed and if so, it
returns.
[akpm@linux-foundation.org: Fix build errors]
[aarcange@redhat.com: fix count_vm_event preempt in memory compaction direct reclaim]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch is the core of a mechanism which compacts memory in a zone by
relocating movable pages towards the end of the zone.
A single compaction run involves a migration scanner and a free scanner.
Both scanners operate on pageblock-sized areas in the zone. The migration
scanner starts at the bottom of the zone and searches for all movable
pages within each area, isolating them onto a private list called
migratelist. The free scanner starts at the top of the zone and searches
for suitable areas and consumes the free pages within making them
available for the migration scanner. The pages isolated for migration are
then migrated to the newly isolated free pages.
[aarcange@redhat.com: Fix unsafe optimisation]
[mel@csn.ul.ie: do not schedule work on other CPUs for compaction]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are two types of zonelist ordering methodologies:
- node order, preferring allocations on a node to stay local to and
- zone order, preferring allocations come from a higher zone to avoid
allocating in lowmem zones even though they may not be local.
The ordering technique used by the kernel is configurable on the command
line, but also has some logic to determine what the default should be.
This logic currently lacks knowledge of systems where a node may only have
lowmem. For such systems, it is necessary to use node order so that
GFP_KERNEL allocations may be satisfied by nodes consisting of only
lowmem.
If zone order is used, GFP_KERNEL allocations to such nodes are actually
allocated on a node with local affinity that includes ZONE_NORMAL.
This change defaults to node zonelist ordering if any node lacks
ZONE_NORMAL.
To force zone order, append 'numa_zonelist_order=zone' to the kernel
command line.
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Before applying this patch, cpuset updates task->mems_allowed and
mempolicy by setting all new bits in the nodemask first, and clearing all
old unallowed bits later. But in the way, the allocator may find that
there is no node to alloc memory.
The reason is that cpuset rebinds the task's mempolicy, it cleans the
nodes which the allocater can alloc pages on, for example:
(mpol: mempolicy)
task1 task1's mpol task2
alloc page 1
alloc on node0? NO 1
1 change mems from 1 to 0
1 rebind task1's mpol
0-1 set new bits
0 clear disallowed bits
alloc on node1? NO 0
...
can't alloc page
goto oom
This patch fixes this problem by expanding the nodes range first(set newly
allowed bits) and shrink it lazily(clear newly disallowed bits). So we
use a variable to tell the write-side task that read-side task is reading
nodemask, and the write-side task clears newly disallowed nodes after
read-side task ends the current memory allocation.
[akpm@linux-foundation.org: fix spello]
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Paul Menage <menage@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In order to reduce fragmentation, this patch classifies freed pages in two
groups according to their probability of being part of a high order merge.
Pages belonging to a compound whose next-highest buddy is free are more
likely to be part of a high order merge in the near future, so they will
be added at the tail of the freelist. The remaining pages are put at the
front of the freelist.
In this way, the pages that are more likely to cause a big merge are kept
free longer. Consequently there is a tendency to aggregate the
long-living allocations on a subset of the compounds, reducing the
fragmentation.
This heuristic was tested on three machines, x86, x86-64 and ppc64 with
3GB of RAM in each machine. The tests were kernbench, netperf, sysbench
and STREAM for performance and a high-order stress test for huge page
allocations.
KernBench X86
Elapsed mean 374.77 ( 0.00%) 375.10 (-0.09%)
User mean 649.53 ( 0.00%) 650.44 (-0.14%)
System mean 54.75 ( 0.00%) 54.18 ( 1.05%)
CPU mean 187.75 ( 0.00%) 187.25 ( 0.27%)
KernBench X86-64
Elapsed mean 94.45 ( 0.00%) 94.01 ( 0.47%)
User mean 323.27 ( 0.00%) 322.66 ( 0.19%)
System mean 36.71 ( 0.00%) 36.50 ( 0.57%)
CPU mean 380.75 ( 0.00%) 381.75 (-0.26%)
KernBench PPC64
Elapsed mean 173.45 ( 0.00%) 173.74 (-0.17%)
User mean 587.99 ( 0.00%) 587.95 ( 0.01%)
System mean 60.60 ( 0.00%) 60.57 ( 0.05%)
CPU mean 373.50 ( 0.00%) 372.75 ( 0.20%)
Nothing notable for kernbench.
NetPerf UDP X86
64 42.68 ( 0.00%) 42.77 ( 0.21%)
128 85.62 ( 0.00%) 85.32 (-0.35%)
256 170.01 ( 0.00%) 168.76 (-0.74%)
1024 655.68 ( 0.00%) 652.33 (-0.51%)
2048 1262.39 ( 0.00%) 1248.61 (-1.10%)
3312 1958.41 ( 0.00%) 1944.61 (-0.71%)
4096 2345.63 ( 0.00%) 2318.83 (-1.16%)
8192 4132.90 ( 0.00%) 4089.50 (-1.06%)
16384 6770.88 ( 0.00%) 6642.05 (-1.94%)*
NetPerf UDP X86-64
64 148.82 ( 0.00%) 154.92 ( 3.94%)
128 298.96 ( 0.00%) 312.95 ( 4.47%)
256 583.67 ( 0.00%) 626.39 ( 6.82%)
1024 2293.18 ( 0.00%) 2371.10 ( 3.29%)
2048 4274.16 ( 0.00%) 4396.83 ( 2.79%)
3312 6356.94 ( 0.00%) 6571.35 ( 3.26%)
4096 7422.68 ( 0.00%) 7635.42 ( 2.79%)*
8192 12114.81 ( 0.00%)* 12346.88 ( 1.88%)
16384 17022.28 ( 0.00%)* 17033.19 ( 0.06%)*
1.64% 2.73%
NetPerf UDP PPC64
64 49.98 ( 0.00%) 50.25 ( 0.54%)
128 98.66 ( 0.00%) 100.95 ( 2.27%)
256 197.33 ( 0.00%) 191.03 (-3.30%)
1024 761.98 ( 0.00%) 785.07 ( 2.94%)
2048 1493.50 ( 0.00%) 1510.85 ( 1.15%)
3312 2303.95 ( 0.00%) 2271.72 (-1.42%)
4096 2774.56 ( 0.00%) 2773.06 (-0.05%)
8192 4918.31 ( 0.00%) 4793.59 (-2.60%)
16384 7497.98 ( 0.00%) 7749.52 ( 3.25%)
The tests are run to have confidence limits within 1%. Results marked
with a * were not confident although in this case, it's only outside by
small amounts. Even with some results that were not confident, the
netperf UDP results were generally positive.
NetPerf TCP X86
64 652.25 ( 0.00%)* 648.12 (-0.64%)*
23.80% 22.82%
128 1229.98 ( 0.00%)* 1220.56 (-0.77%)*
21.03% 18.90%
256 2105.88 ( 0.00%) 1872.03 (-12.49%)*
1.00% 16.46%
1024 3476.46 ( 0.00%)* 3548.28 ( 2.02%)*
13.37% 11.39%
2048 4023.44 ( 0.00%)* 4231.45 ( 4.92%)*
9.76% 12.48%
3312 4348.88 ( 0.00%)* 4396.96 ( 1.09%)*
6.49% 8.75%
4096 4726.56 ( 0.00%)* 4877.71 ( 3.10%)*
9.85% 8.50%
8192 4732.28 ( 0.00%)* 5777.77 (18.10%)*
9.13% 13.04%
16384 5543.05 ( 0.00%)* 5906.24 ( 6.15%)*
7.73% 8.68%
NETPERF TCP X86-64
netperf-tcp-vanilla-netperf netperf-tcp
tcp-vanilla pgalloc-delay
64 1895.87 ( 0.00%)* 1775.07 (-6.81%)*
5.79% 4.78%
128 3571.03 ( 0.00%)* 3342.20 (-6.85%)*
3.68% 6.06%
256 5097.21 ( 0.00%)* 4859.43 (-4.89%)*
3.02% 2.10%
1024 8919.10 ( 0.00%)* 8892.49 (-0.30%)*
5.89% 6.55%
2048 10255.46 ( 0.00%)* 10449.39 ( 1.86%)*
7.08% 7.44%
3312 10839.90 ( 0.00%)* 10740.15 (-0.93%)*
6.87% 7.33%
4096 10814.84 ( 0.00%)* 10766.97 (-0.44%)*
6.86% 8.18%
8192 11606.89 ( 0.00%)* 11189.28 (-3.73%)*
7.49% 5.55%
16384 12554.88 ( 0.00%)* 12361.22 (-1.57%)*
7.36% 6.49%
NETPERF TCP PPC64
netperf-tcp-vanilla-netperf netperf-tcp
tcp-vanilla pgalloc-delay
64 594.17 ( 0.00%) 596.04 ( 0.31%)*
1.00% 2.29%
128 1064.87 ( 0.00%)* 1074.77 ( 0.92%)*
1.30% 1.40%
256 1852.46 ( 0.00%)* 1856.95 ( 0.24%)
1.25% 1.00%
1024 3839.46 ( 0.00%)* 3813.05 (-0.69%)
1.02% 1.00%
2048 4885.04 ( 0.00%)* 4881.97 (-0.06%)*
1.15% 1.04%
3312 5506.90 ( 0.00%) 5459.72 (-0.86%)
4096 6449.19 ( 0.00%) 6345.46 (-1.63%)
8192 7501.17 ( 0.00%) 7508.79 ( 0.10%)
16384 9618.65 ( 0.00%) 9490.10 (-1.35%)
There was a distinct lack of confidence in the X86* figures so I included
what the devation was where the results were not confident. Many of the
results, whether gains or losses were within the standard deviation so no
solid conclusion can be reached on performance impact. Looking at the
figures, only the X86-64 ones look suspicious with a few losses that were
outside the noise. However, the results were so unstable that without
knowing why they vary so much, a solid conclusion cannot be reached.
SYSBENCH X86
sysbench-vanilla pgalloc-delay
1 7722.85 ( 0.00%) 7756.79 ( 0.44%)
2 14901.11 ( 0.00%) 13683.44 (-8.90%)
3 15171.71 ( 0.00%) 14888.25 (-1.90%)
4 14966.98 ( 0.00%) 15029.67 ( 0.42%)
5 14370.47 ( 0.00%) 14865.00 ( 3.33%)
6 14870.33 ( 0.00%) 14845.57 (-0.17%)
7 14429.45 ( 0.00%) 14520.85 ( 0.63%)
8 14354.35 ( 0.00%) 14362.31 ( 0.06%)
SYSBENCH X86-64
1 17448.70 ( 0.00%) 17484.41 ( 0.20%)
2 34276.39 ( 0.00%) 34251.00 (-0.07%)
3 50805.25 ( 0.00%) 50854.80 ( 0.10%)
4 66667.10 ( 0.00%) 66174.69 (-0.74%)
5 66003.91 ( 0.00%) 65685.25 (-0.49%)
6 64981.90 ( 0.00%) 65125.60 ( 0.22%)
7 64933.16 ( 0.00%) 64379.23 (-0.86%)
8 63353.30 ( 0.00%) 63281.22 (-0.11%)
9 63511.84 ( 0.00%) 63570.37 ( 0.09%)
10 62708.27 ( 0.00%) 63166.25 ( 0.73%)
11 62092.81 ( 0.00%) 61787.75 (-0.49%)
12 61330.11 ( 0.00%) 61036.34 (-0.48%)
13 61438.37 ( 0.00%) 61994.47 ( 0.90%)
14 62304.48 ( 0.00%) 62064.90 (-0.39%)
15 63296.48 ( 0.00%) 62875.16 (-0.67%)
16 63951.76 ( 0.00%) 63769.09 (-0.29%)
SYSBENCH PPC64
-sysbench-pgalloc-delay-sysbench
sysbench-vanilla pgalloc-delay
1 7645.08 ( 0.00%) 7467.43 (-2.38%)
2 14856.67 ( 0.00%) 14558.73 (-2.05%)
3 21952.31 ( 0.00%) 21683.64 (-1.24%)
4 27946.09 ( 0.00%) 28623.29 ( 2.37%)
5 28045.11 ( 0.00%) 28143.69 ( 0.35%)
6 27477.10 ( 0.00%) 27337.45 (-0.51%)
7 26489.17 ( 0.00%) 26590.06 ( 0.38%)
8 26642.91 ( 0.00%) 25274.33 (-5.41%)
9 25137.27 ( 0.00%) 24810.06 (-1.32%)
10 24451.99 ( 0.00%) 24275.85 (-0.73%)
11 23262.20 ( 0.00%) 23674.88 ( 1.74%)
12 24234.81 ( 0.00%) 23640.89 (-2.51%)
13 24577.75 ( 0.00%) 24433.50 (-0.59%)
14 25640.19 ( 0.00%) 25116.52 (-2.08%)
15 26188.84 ( 0.00%) 26181.36 (-0.03%)
16 26782.37 ( 0.00%) 26255.99 (-2.00%)
Again, there is little to conclude here. While there are a few losses,
the results vary by +/- 8% in some cases. They are the results of most
concern as there are some large losses but it's also within the variance
typically seen between kernel releases.
The STREAM results varied so little and are so verbose that I didn't
include them here.
The final test stressed how many huge pages can be allocated. The
absolute number of huge pages allocated are the same with or without the
page. However, the "unusability free space index" which is a measure of
external fragmentation was slightly lower (lower is better) throughout the
lifetime of the system. I also measured the latency of how long it took
to successfully allocate a huge page. The latency was slightly lower and
on X86 and PPC64, more huge pages were allocated almost immediately from
the free lists. The improvement is slight but there.
[mel@csn.ul.ie: Tested, reworked for less branches]
[czoccolo@gmail.com: fix oops by checking pfn_valid_within()]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Corrado Zoccolo <czoccolo@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__zone_pcp_update() iterates over NR_CPUS instead of limiting the access
to the possible cpus. This might result in access to uninitialized areas
as the per cpu allocator only populates the per cpu memory for possible
cpus.
This problem was created as a result of the dynamic allocation of pagesets
from percpu memory that went in during the merge window - commit
99dcc3e5a9 ("this_cpu: Page allocator
conversion").
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
free_area_init_nodes() emits pfn ranges for all zones on the system.
There may be no pages on a higher zone, however, due to memory limitations
or the use of the mem= kernel parameter. For example:
Zone PFN ranges:
DMA 0x00000001 -> 0x00001000
DMA32 0x00001000 -> 0x00100000
Normal 0x00100000 -> 0x00100000
The implementation copies the previous zone's highest pfn, if any, as the
next zone's lowest pfn. If its highest pfn is then greater than the
amount of addressable memory, the upper memory limit is used instead.
Thus, both the lowest and highest possible pfn for higher zones without
memory may be the same.
The pfn range for zones without memory is now shown as "empty" instead.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are quite a few GFP_KERNEL memory allocations made during
suspend/hibernation and resume that may cause the system to hang, because
the I/O operations they depend on cannot be completed due to the
underlying devices being suspended.
Avoid this problem by clearing the __GFP_IO and __GFP_FS bits in
gfp_allowed_mask before suspend/hibernation and restoring the original
values of these bits in gfp_allowed_mask durig the subsequent resume.
[akpm@linux-foundation.org: fix CONFIG_PM=n linkage]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Maxim Levitsky <maximlevitsky@gmail.com>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
commit e815af95 ("change all_unreclaimable zone member to flags") changed
all_unreclaimable member to bit flag. But it had an undesireble side
effect. free_one_page() is one of most hot path in linux kernel and
increasing atomic ops in it can reduce kernel performance a bit.
Thus, this patch revert such commit partially. at least
all_unreclaimable shouldn't share memory word with other zone flags.
[akpm@linux-foundation.org: fix patch interaction]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
free_hot_page() is just a wrapper around free_hot_cold_page() with
parameter 'cold = 0'. After adding a clear comment for
free_hot_cold_page(), it is reasonable to remove a level of call.
[akpm@linux-foundation.org: fix build]
Signed-off-by: Li Hong <lihong.hi@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Li Ming Chun <macli@brc.ubc.ca>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Americo Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move a call of trace_mm_page_free_direct() from free_hot_page() to
free_hot_cold_page(). It is clearer and close to kmemcheck_free_shadow(),
as it is done in function __free_pages_ok().
Signed-off-by: Li Hong <lihong.hi@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Li Ming Chun <macli@brc.ubc.ca>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
trace_mm_page_free_direct() is called in function __free_pages(). But it
is called again in free_hot_page() if order == 0 and produce duplicate
records in trace file for mm_page_free_direct event. As below:
K-PID CPU# TIMESTAMP FUNCTION
gnome-terminal-1567 [000] 4415.246466: mm_page_free_direct: page=ffffea0003db9f40 pfn=1155800 order=0
gnome-terminal-1567 [000] 4415.246468: mm_page_free_direct: page=ffffea0003db9f40 pfn=1155800 order=0
gnome-terminal-1567 [000] 4415.246506: mm_page_alloc: page=ffffea0003db9f40 pfn=1155800 order=0 migratetype=0 gfp_flags=GFP_KERNEL
gnome-terminal-1567 [000] 4415.255557: mm_page_free_direct: page=ffffea0003db9f40 pfn=1155800 order=0
gnome-terminal-1567 [000] 4415.255557: mm_page_free_direct: page=ffffea0003db9f40 pfn=1155800 order=0
This patch removes the first call and adds a call to
trace_mm_page_free_direct() in __free_pages_ok().
Signed-off-by: Li Hong <lihong.hi@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Li Ming Chun <macli@brc.ubc.ca>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'x86-bootmem-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (30 commits)
early_res: Need to save the allocation name in drop_range_partial()
sparsemem: Fix compilation on PowerPC
early_res: Add free_early_partial()
x86: Fix non-bootmem compilation on PowerPC
core: Move early_res from arch/x86 to kernel/
x86: Add find_fw_memmap_area
Move round_up/down to kernel.h
x86: Make 32bit support NO_BOOTMEM
early_res: Enhance check_and_double_early_res
x86: Move back find_e820_area to e820.c
x86: Add find_early_area_size
x86: Separate early_res related code from e820.c
x86: Move bios page reserve early to head32/64.c
sparsemem: Put mem map for one node together.
sparsemem: Put usemap for one node together
x86: Make 64 bit use early_res instead of bootmem before slab
x86: Only call dma32_reserve_bootmem 64bit !CONFIG_NUMA
x86: Make early_node_mem get mem > 4 GB if possible
x86: Dynamically increase early_res array size
x86: Introduce max_early_res and early_res_count
...
These build errors on some non-x86 platforms (PowerPC for example):
mm/page_alloc.c: In function '__alloc_memory_core_early':
mm/page_alloc.c:3468: error: implicit declaration of function 'find_early_area'
mm/page_alloc.c:3483: error: implicit declaration of function 'reserve_early_without_check'
The function is only needed on CONFIG_NO_BOOTMEM.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Weiner <hannes@saeurebad.de>
Cc: Mel Gorman <mel@csn.ul.ie>
LKML-Reference: <4B747239.4070907@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Finally we can use early_res to replace bootmem for x86_64 now.
Still can use CONFIG_NO_BOOTMEM to enable it or not.
-v2: fix 32bit compiling about MAX_DMA32_PFN
-v3: folded bug fix from LKML message below
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4B747239.4070907@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
After memory pressure has forced it to dip into the reserves, 2.6.32's
5f8dcc2121 "page-allocator: split per-cpu
list into one-list-per-migrate-type" has been returning MIGRATE_RESERVE
pages to the MIGRATE_MOVABLE free_list: in some sense depleting reserves.
Fix that in the most straightforward way (which, considering the overheads
of alternative approaches, is Mel's preference): the right migratetype is
already in page_private(page), but free_pcppages_bulk() wasn't using it.
How did this bug show up? As a 20% slowdown in my tmpfs loop kbuild
swapping tests, on PowerMac G5 with SLUB allocator. Bisecting to that
commit was easy, but explaining the magnitude of the slowdown not easy.
The same effect appears, but much less markedly, with SLAB, and even
less markedly on other machines (the PowerMac divides into fewer zones
than x86, I think that may be a factor). We guess that lumpy reclaim
of short-lived high-order pages is implicated in some way, and probably
this bug has been tickling a poor decision somewhere in page reclaim.
But instrumentation hasn't told me much, I've run out of time and
imagination to determine exactly what's going on, and shouldn't hold up
the fix any longer: it's valid, and might even fix other misbehaviours.
Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
commit f2260e6b (page allocator: update NR_FREE_PAGES only as necessary)
made one minor regression. if __rmqueue() was failed, NR_FREE_PAGES stat
go wrong. this patch fixes it.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reported-by: Huang Shijie <shijie8@gmail.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current check for 'backward merging' within add_active_range() does
not seem correct. start_pfn must be compared against
early_node_map[i].start_pfn (and NOT against .end_pfn) to find out whether
the new region is backward-mergeable with the existing range.
Signed-off-by: Kazuhisa Ichikawa <ki@epsilou.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the per cpu allocator functionality to avoid per cpu arrays in struct zone.
This drastically reduces the size of struct zone for systems with large
amounts of processors and allows placement of critical variables of struct
zone in one cacheline even on very large systems.
Another effect is that the pagesets of one processor are placed near one
another. If multiple pagesets from different zones fit into one cacheline
then additional cacheline fetches can be avoided on the hot paths when
allocating memory from multiple zones.
Bootstrap becomes simpler if we use the same scheme for UP, SMP, NUMA. #ifdefs
are reduced and we can drop the zone_pcp macro.
Hotplug handling is also simplified since cpu alloc can bring up and
shut down cpu areas for a specific cpu as a whole. So there is no need to
allocate or free individual pagesets.
V7-V8:
- Explain chicken egg dilemmna with percpu allocator.
V4-V5:
- Fix up cases where per_cpu_ptr is called before irq disable
- Integrate the bootstrap logic that was separate before.
tj: Build failure in pageset_cpuup_callback() due to missing ret
variable fixed.
Reviewed-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
The zone list code clearly cannot tolerate concurrent writers (I couldn't
find any locks for that), so simply add a global mutex. No need for RCU
in this case.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (36 commits)
powerpc/gc/wii: Remove get_irq_desc()
powerpc/gc/wii: hlwd-pic: convert irq_desc.lock to raw_spinlock
powerpc/gamecube/wii: Fix off-by-one error in ugecon/usbgecko_udbg
powerpc/mpic: Fix problem that affinity is not updated
powerpc/mm: Fix stupid bug in subpge protection handling
powerpc/iseries: use DECLARE_COMPLETION_ONSTACK for non-constant completion
powerpc: Fix MSI support on U4 bridge PCIe slot
powerpc: Handle VSX alignment faults correctly in little-endian mode
powerpc/mm: Fix typo of cpumask_clear_cpu()
powerpc/mm: Fix hash_utils_64.c compile errors with DEBUG enabled.
powerpc: Convert BUG() to use unreachable()
powerpc/pseries: Make declarations of cpu_hotplug_driver_lock() ANSI compatible.
powerpc/pseries: Don't panic when H_PROD fails during cpu-online.
powerpc/mm: Fix a WARN_ON() with CONFIG_DEBUG_PAGEALLOC and CONFIG_DEBUG_VM
powerpc/defconfigs: Set HZ=100 on pseries and ppc64 defconfigs
powerpc/defconfigs: Disable token ring in powerpc defconfigs
powerpc/defconfigs: Reduce 64bit vmlinux by making acenic and cramfs modules
powerpc/pseries: Select XICS and PCI_MSI PSERIES
powerpc/85xx: Wrong variable returned on error
powerpc/iseries: Convert to proc_fops
...
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, irq: Allow 0xff for /proc/irq/[n]/smp_affinity on an 8-cpu system
Makefile: Unexport LC_ALL instead of clearing it
x86: Fix objdump version check in arch/x86/tools/chkobjdump.awk
x86: Reenable TSC sync check at boot, even with NONSTOP_TSC
x86: Don't use POSIX character classes in gen-insn-attr-x86.awk
Makefile: set LC_CTYPE, LC_COLLATE, LC_NUMERIC to C
x86: Increase MAX_EARLY_RES; insufficient on 32-bit NUMA
x86: Fix checking of SRAT when node 0 ram is not from 0
x86, cpuid: Add "volatile" to asm in native_cpuid()
x86, msr: msrs_alloc/free for CONFIG_SMP=n
x86, amd: Get multi-node CPU info from NodeId MSR instead of PCI config space
x86: Add IA32_TSC_AUX MSR and use it
x86, msr/cpuid: Register enough minors for the MSR and CPUID drivers
initramfs: add missing decompressor error check
bzip2: Add missing checks for malloc returning NULL
bzip2/lzma/gzip: pre-boot malloc doesn't return NULL on failure
Memory balloon drivers can allocate a large amount of memory which is not
movable but could be freed to accomodate memory hotplug remove.
Prior to calling the memory hotplug notifier chain the memory in the
pageblock is isolated. Currently, if the migrate type is not
MIGRATE_MOVABLE the isolation will not proceed, causing the memory removal
for that page range to fail.
Rather than failing pageblock isolation if the migrateteype is not
MIGRATE_MOVABLE, this patch checks if all of the pages in the pageblock,
and not on the LRU, are owned by a registered balloon driver (or other
entity) using a notifier chain. If all of the non-movable pages are owned
by a balloon, they can be freed later through the memory notifier chain
and the range can still be isolated in set_migratetype_isolate().
Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Brian King <brking@linux.vnet.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Gerald Schaefer <geralds@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Found one system that boot from socket1 instead of socket0, SRAT get rejected...
[ 0.000000] SRAT: Node 1 PXM 0 0-a0000
[ 0.000000] SRAT: Node 1 PXM 0 100000-80000000
[ 0.000000] SRAT: Node 1 PXM 0 100000000-2080000000
[ 0.000000] SRAT: Node 0 PXM 1 2080000000-4080000000
[ 0.000000] SRAT: Node 2 PXM 2 4080000000-6080000000
[ 0.000000] SRAT: Node 3 PXM 3 6080000000-8080000000
[ 0.000000] SRAT: Node 4 PXM 4 8080000000-a080000000
[ 0.000000] SRAT: Node 5 PXM 5 a080000000-c080000000
[ 0.000000] SRAT: Node 6 PXM 6 c080000000-e080000000
[ 0.000000] SRAT: Node 7 PXM 7 e080000000-10080000000
...
[ 0.000000] NUMA: Allocated memnodemap from 500000 - 701040
[ 0.000000] NUMA: Using 20 for the hash shift.
[ 0.000000] Adding active range (0, 0x2080000, 0x4080000) 0 entries of 3200 used
[ 0.000000] Adding active range (1, 0x0, 0x96) 1 entries of 3200 used
[ 0.000000] Adding active range (1, 0x100, 0x7f750) 2 entries of 3200 used
[ 0.000000] Adding active range (1, 0x100000, 0x2080000) 3 entries of 3200 used
[ 0.000000] Adding active range (2, 0x4080000, 0x6080000) 4 entries of 3200 used
[ 0.000000] Adding active range (3, 0x6080000, 0x8080000) 5 entries of 3200 used
[ 0.000000] Adding active range (4, 0x8080000, 0xa080000) 6 entries of 3200 used
[ 0.000000] Adding active range (5, 0xa080000, 0xc080000) 7 entries of 3200 used
[ 0.000000] Adding active range (6, 0xc080000, 0xe080000) 8 entries of 3200 used
[ 0.000000] Adding active range (7, 0xe080000, 0x10080000) 9 entries of 3200 used
[ 0.000000] SRAT: PXMs only cover 917504MB of your 1048566MB e820 RAM. Not used.
[ 0.000000] SRAT: SRAT not used.
the early_node_map is not sorted because node0 with non zero start come first.
so try to sort it right away after all regions are registered.
also fixs refression by 8716273c (x86: Export srat physical topology)
-v2: make it more solid to handle cross node case like node0 [0,4g), [8,12g) and node1 [4g, 8g), [12g, 16g)
-v3: update comments.
Reported-and-tested-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4B2579D2.3010201@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: (34 commits)
HWPOISON: Remove stray phrase in a comment
HWPOISON: Try to allocate migration page on the same node
HWPOISON: Don't do early filtering if filter is disabled
HWPOISON: Add a madvise() injector for soft page offlining
HWPOISON: Add soft page offline support
HWPOISON: Undefine short-hand macros after use to avoid namespace conflict
HWPOISON: Use new shake_page in memory_failure
HWPOISON: Use correct name for MADV_HWPOISON in documentation
HWPOISON: mention HWPoison in Kconfig entry
HWPOISON: Use get_user_page_fast in hwpoison madvise
HWPOISON: add an interface to switch off/on all the page filters
HWPOISON: add memory cgroup filter
memcg: add accessor to mem_cgroup.css
memcg: rename and export try_get_mem_cgroup_from_page()
HWPOISON: add page flags filter
mm: export stable page flags
HWPOISON: limit hwpoison injector to known page types
HWPOISON: add fs/device filters
HWPOISON: return 0 to indicate success reliably
HWPOISON: make semantics of IGNORED/DELAYED clear
...
Fix node-oriented allocation handling in oom-kill.c I myself think of this
as a bugfix not as an ehnancement.
In these days, things are changed as
- alloc_pages() eats nodemask as its arguments, __alloc_pages_nodemask().
- mempolicy don't maintain its own private zonelists.
(And cpuset doesn't use nodemask for __alloc_pages_nodemask())
So, current oom-killer's check function is wrong.
This patch does
- check nodemask, if nodemask && nodemask doesn't cover all
node_states[N_HIGH_MEMORY], this is CONSTRAINT_MEMORY_POLICY.
- Scan all zonelist under nodemask, if it hits cpuset's wall
this faiulre is from cpuset.
And
- modifies the caller of out_of_memory not to call oom if __GFP_THISNODE.
This doesn't change "current" behavior. If callers use __GFP_THISNODE
it should handle "page allocation failure" by itself.
- handle __GFP_NOFAIL+__GFP_THISNODE path.
This is something like a FIXME but this gfpmask is not used now.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hioryu@jp.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Most free pages in the buddy system have no PG_buddy set.
Introduce is_free_buddy_page() for detecting them reliably.
CC: Nick Piggin <npiggin@suse.de>
CC: Mel Gorman <mel@linux.vnet.ibm.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Remove three degrees of obfuscation, left over from when we had
CONFIG_UNEVICTABLE_LRU. MLOCK_PAGES is CONFIG_HAVE_MLOCKED_PAGE_BIT is
CONFIG_HAVE_MLOCK is CONFIG_MMU. rmap.o (and memory-failure.o) are only
built when CONFIG_MMU, so don't need such conditions at all.
Somehow, I feel no compulsion to remove the CONFIG_HAVE_MLOCK* lines from
169 defconfigs: leave those to evolve in due course.
Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Izik Eidus <ieidus@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Nick Piggin <npiggin@suse.de>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 341ce06f69 ("page allocator:
calculate the alloc_flags for allocation only once") altered watermark
logic slightly by allowing rt_tasks that are handling an interrupt to set
ALLOC_HARDER. This patch brings the watermark logic more in line with
2.6.30.
This change results in a reduction of the number high-order GFP_ATOMIC
allocation failures reported. See
http://www.gossamer-threads.com/lists/linux/kernel/1144153
[rientjes@google.com: Spotted the problem]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If a direct reclaim makes no forward progress, it considers whether it
should go OOM or not. Whether OOM is triggered or not, it may retry the
allocation afterwards. In times past, this would always wake kswapd as
well but currently, kswapd is not woken up after direct reclaim fails.
For order-0 allocations, this makes little difference but if there is a
heavy mix of higher-order allocations that direct reclaim is failing for,
it might mean that kswapd is not rewoken for higher orders as much as it
did previously.
This patch wakes up kswapd when an allocation is being retried after a
direct reclaim failure. It would be expected that kswapd is already
awake, but this has the effect of telling kswapd to reclaim at the higher
order as well.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Revert
commit 71de1ccbe1
Author: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
AuthorDate: Mon Sep 21 17:01:31 2009 -0700
Commit: Linus Torvalds <torvalds@linux-foundation.org>
CommitDate: Tue Sep 22 07:17:27 2009 -0700
mm: oom analysis: add buffer cache information to show_free_areas()
show_free_areas() is called during page allocation failures, and page
allocation failures can occur in any calling context.
But nr_blockdev_pages() takes VFS locks which should not be taken from
hard IRQ context (at least). The result is lockdep warnings (and
deadlockability) during page allocation failures.
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: (21 commits)
HWPOISON: Enable error_remove_page on btrfs
HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs
HWPOISON: Add madvise() based injector for hardware poisoned pages v4
HWPOISON: Enable error_remove_page for NFS
HWPOISON: Enable .remove_error_page for migration aware file systems
HWPOISON: The high level memory error handler in the VM v7
HWPOISON: Add PR_MCE_KILL prctl to control early kill behaviour per process
HWPOISON: shmem: call set_page_dirty() with locked page
HWPOISON: Define a new error_remove_page address space op for async truncation
HWPOISON: Add invalidate_inode_page
HWPOISON: Refactor truncate to allow direct truncating of page v2
HWPOISON: check and isolate corrupted free pages v2
HWPOISON: Handle hardware poisoned pages in try_to_unmap
HWPOISON: Use bitmask/action code for try_to_unmap behaviour
HWPOISON: x86: Add VM_FAULT_HWPOISON handling to x86 page fault handler v2
HWPOISON: Add poison check to page fault handling
HWPOISON: Add basic support for poisoned pages in fault handler v3
HWPOISON: Add new SIGBUS error codes for hardware poison signals
HWPOISON: Add support for poison swap entries v2
HWPOISON: Export some rmap vma locking to outside world
...
It's unused.
It isn't needed -- read or write flag is already passed and sysctl
shouldn't care about the rest.
It _was_ used in two places at arch/frv for some reason.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move highest_memmap_pfn __read_mostly from page_alloc.c next to zero_pfn
__read_mostly in memory.c: to help them share a cacheline, since they're
very often tested together in vm_normal_page().
Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Rik van Riel <riel@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When round-robin freeing pages from the PCP lists, empty lists may be
encountered. In the event one of the lists has more pages than another,
there may be numerous checks for list_empty() which is undesirable. This
patch maintains a count of pages to free which is incremented when empty
lists are encountered. The intention is that more pages will then be
freed from fuller lists than the empty ones reducing the number of empty
list checks in the free path.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The following two patches remove searching in the page allocator fast-path
by maintaining multiple free-lists in the per-cpu structure. At the time
the search was introduced, increasing the per-cpu structures would waste a
lot of memory as per-cpu structures were statically allocated at
compile-time. This is no longer the case.
The patches are as follows. They are based on mmotm-2009-08-27.
Patch 1 adds multiple lists to struct per_cpu_pages, one per
migratetype that can be stored on the PCP lists.
Patch 2 notes that the pcpu drain path check empty lists multiple times. The
patch reduces the number of checks by maintaining a count of free
lists encountered. Lists containing pages will then free multiple
pages in batch
The patches were tested with kernbench, netperf udp/tcp, hackbench and
sysbench. The netperf tests were not bound to any CPU in particular and
were run such that the results should be 99% confidence that the reported
results are within 1% of the estimated mean. sysbench was run with a
postgres background and read-only tests. Similar to netperf, it was run
multiple times so that it's 99% confidence results are within 1%. The
patches were tested on x86, x86-64 and ppc64 as
x86: Intel Pentium D 3GHz with 8G RAM (no-brand machine)
kernbench - No significant difference, variance well within noise
netperf-udp - 1.34% to 2.28% gain
netperf-tcp - 0.45% to 1.22% gain
hackbench - Small variances, very close to noise
sysbench - Very small gains
x86-64: AMD Phenom 9950 1.3GHz with 8G RAM (no-brand machine)
kernbench - No significant difference, variance well within noise
netperf-udp - 1.83% to 10.42% gains
netperf-tcp - No conclusive until buffer >= PAGE_SIZE
4096 +15.83%
8192 + 0.34% (not significant)
16384 + 1%
hackbench - Small gains, very close to noise
sysbench - 0.79% to 1.6% gain
ppc64: PPC970MP 2.5GHz with 10GB RAM (it's a terrasoft powerstation)
kernbench - No significant difference, variance well within noise
netperf-udp - 2-3% gain for almost all buffer sizes tested
netperf-tcp - losses on small buffers, gains on larger buffers
possibly indicates some bad caching effect.
hackbench - No significant difference
sysbench - 2-4% gain
This patch:
Currently the per-cpu page allocator searches the PCP list for pages of
the correct migrate-type to reduce the possibility of pages being
inappropriate placed from a fragmentation perspective. This search is
potentially expensive in a fast-path and undesirable. Splitting the
per-cpu list into multiple lists increases the size of a per-cpu structure
and this was potentially a major problem at the time the search was
introduced. These problem has been mitigated as now only the necessary
number of structures is allocated for the running system.
This patch replaces a list search in the per-cpu allocator with one list
per migrate type. The potential snag with this approach is when bulk
freeing pages. We round-robin free pages based on migrate type which has
little bearing on the cache hotness of the page and potentially checks
empty lists repeatedly in the event the majority of PCP pages are of one
type.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Nick Piggin <npiggin@suse.de>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For mem_cgroup, shrink_zone() may call shrink_list() with nr_to_scan=1, in
which case shrink_list() _still_ calls isolate_pages() with the much
larger SWAP_CLUSTER_MAX. It effectively scales up the inactive list scan
rate by up to 32 times.
For example, with 16k inactive pages and DEF_PRIORITY=12, (16k >> 12)=4.
So when shrink_zone() expects to scan 4 pages in the active/inactive list,
the active list will be scanned 4 pages, while the inactive list will be
(over) scanned SWAP_CLUSTER_MAX=32 pages in effect. And that could break
the balance between the two lists.
It can further impact the scan of anon active list, due to the anon
active/inactive ratio rebalance logic in balance_pgdat()/shrink_zone():
inactive anon list over scanned => inactive_anon_is_low() == TRUE
=> shrink_active_list()
=> active anon list over scanned
So the end result may be
- anon inactive => over scanned
- anon active => over scanned (maybe not as much)
- file inactive => over scanned
- file active => under scanned (relatively)
The accesses to nr_saved_scan are not lock protected and so not 100%
accurate, however we can tolerate small errors and the resulted small
imbalanced scan rates between zones.
Cc: Rik van Riel <riel@redhat.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is being done by allowing boot time allocations to specify that they
may want a sub-page sized amount of memory.
Overall this seems more consistent with the other hash table allocations,
and allows making two supposedly mm-only variables really mm-only
(nr_{kernel,all}_pages).
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After anti-fragmentation was merged, a bug was reported whereby devices
that depended on high-order atomic allocations were failing. The solution
was to preserve a property in the buddy allocator which tended to keep the
minimum number of free pages in the zone at the lower physical addresses
and contiguous. To preserve this property, MIGRATE_RESERVE was introduced
and a number of pageblocks at the start of a zone would be marked
"reserve", the number of which depended on min_free_kbytes.
Anti-fragmentation works by avoiding the mixing of page migratetypes
within the same pageblock. One way of helping this is to increase
min_free_kbytes because it becomes less like that it will be necessary to
place pages of of MIGRATE_RESERVE is unbounded, the free memory is kept
there in large contiguous blocks instead of helping anti-fragmentation as
much as it should. With the page-allocator tracepoint patches applied, it
was found during anti-fragmentation tests that the number of
fragmentation-related events were far higher than expected even with
min_free_kbytes at higher values.
This patch limits the number of MIGRATE_RESERVE blocks that exist per zone
to two. For example, with a sufficient min_free_kbytes, 4MB of memory
will be kept aside on an x86-64 and remain more or less free and
contiguous for the systems uptime. This should be sufficient for devices
depending on high-order atomic allocations while helping fragmentation
control when min_free_kbytes is tuned appropriately. As side-effect of
this patch is that the reserve variable is converted to int as unsigned
long was the wrong type to use when ensuring that only the required number
of reserve blocks are created.
With the patches applied, fragmentation-related events as measured by the
page allocator tracepoints were significantly reduced when running some
fragmentation stress-tests on systems with min_free_kbytes tuned to a
value appropriate for hugepage allocations at runtime. On x86, the events
recorded were reduced by 99.8%, on x86-64 by 99.72% and on ppc64 by
99.83%.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The page allocation trace event reports that a page was successfully
allocated but it does not specify where it came from. When analysing
performance, it can be important to distinguish between pages coming from
the per-cpu allocator and pages coming from the buddy lists as the latter
requires the zone lock to the taken and more data structures to be
examined.
This patch adds a trace event for __rmqueue reporting when a page is being
allocated from the buddy lists. It distinguishes between being called to
refill the per-cpu lists or whether it is a high-order allocation.
Similarly, this patch adds an event to catch when the PCP lists are being
drained a little and pages are going back to the buddy lists.
This is trickier to draw conclusions from but high activity on those
events could explain why there were a large number of cache misses on a
page-allocator-intensive workload. The coalescing and splitting of
buddies involves a lot of writing of page metadata and cache line bounces
not to mention the acquisition of an interrupt-safe lock necessary to
enter this path.
[akpm@linux-foundation.org: fix build]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Li Ming Chun <macli@brc.ubc.ca>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fragmentation avoidance depends on being able to use free pages from lists
of the appropriate migrate type. In the event this is not possible,
__rmqueue_fallback() selects a different list and in some circumstances
change the migratetype of the pageblock. Simplistically, the more times
this event occurs, the more likely that fragmentation will be a problem
later for hugepage allocation at least but there are other considerations
such as the order of page being split to satisfy the allocation.
This patch adds a trace event for __rmqueue_fallback() that reports what
page is being used for the fallback, the orders of relevant pages, the
desired migratetype and the migratetype of the lists being used, whether
the pageblock changed type and whether this event is important with
respect to fragmentation avoidance or not. This information can be used
to help analyse fragmentation avoidance and help decide whether
min_free_kbytes should be increased or not.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Li Ming Chun <macli@brc.ubc.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds trace events for the allocation and freeing of pages,
including the freeing of pagevecs. Using the events, it will be known
what struct page and pfns are being allocated and freed and what the call
site was in many cases.
The page alloc tracepoints be used as an indicator as to whether the
workload was heavily dependant on the page allocator or not. You can make
a guess based on vmstat but you can't get a per-process breakdown.
Depending on the call path, the call_site for page allocation may be
__get_free_pages() instead of a useful callsite. Instead of passing down
a return address similar to slab debugging, the user should enable the
stacktrace and seg-addr options to get a proper stack trace.
The pagevec free tracepoint has a different usecase. It can be used to
get a idea of how many pages are being dumped off the LRU and whether it
is kswapd doing the work or a process doing direct reclaim.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Li Ming Chun <macli@brc.ubc.ca>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The function free_cold_page() has no callers so delete it.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrew Morton