Commit Graph

7623 Commits

Author SHA1 Message Date
Jianguo Wu b76ac7e734 mm/mempolicy: use NUMA_NO_NODE
Use more appropriate NUMA_NO_NODE instead of -1

Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.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>
2013-11-13 12:09:06 +09:00
Bob Liu 9f1b868a13 mm: thp: khugepaged: add policy for finding target node
Khugepaged will scan/free HPAGE_PMD_NR normal pages and replace with a
hugepage which is allocated from the node of the first scanned normal
page, but this policy is too rough and may end with unexpected result to
upper users.

The problem is the original page-balancing among all nodes will be
broken after hugepaged started.  Thinking about the case if the first
scanned normal page is allocated from node A, most of other scanned
normal pages are allocated from node B or C..  But hugepaged will always
allocate hugepage from node A which will cause extra memory pressure on
node A which is not the situation before khugepaged started.

This patch try to fix this problem by making khugepaged allocate
hugepage from the node which have max record of scaned normal pages hit,
so that the effect to original page-balancing can be minimized.

The other problem is if normal scanned pages are equally allocated from
Node A,B and C, after khugepaged started Node A will still suffer extra
memory pressure.

Andrew Davidoff reported a related issue several days ago.  He wanted
his application interleaving among all nodes and "numactl
--interleave=all ./test" was used to run the testcase, but the result
wasn't not as expected.

  cat /proc/2814/numa_maps:
  7f50bd440000 interleave:0-3 anon=51403 dirty=51403 N0=435 N1=435 N2=435 N3=50098

The end result showed that most pages are from Node3 instead of
interleave among node0-3 which was unreasonable.

This patch also fix this issue by allocating hugepage round robin from
all nodes have the same record, after this patch the result was as
expected:

  7f78399c0000 interleave:0-3 anon=51403 dirty=51403 N0=12723 N1=12723 N2=13235 N3=12722

The simple testcase is like this:

int main() {
	char *p;
	int i;
	int j;

	for (i=0; i < 200; i++) {
		p = (char *)malloc(1048576);
		printf("malloc done\n");

		if (p == 0) {
			printf("Out of memory\n");
			return 1;
		}
		for (j=0; j < 1048576; j++) {
			p[j] = 'A';
		}
		printf("touched memory\n");

		sleep(1);
	}
	printf("enter sleep\n");
	while(1) {
		sleep(100);
	}
}

[akpm@linux-foundation.org: make last_khugepaged_target_node local to khugepaged_find_target_node()]
Reported-by: Andrew Davidoff <davidoff@qedmf.net>
Tested-by: Andrew Davidoff <davidoff@qedmf.net>
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:06 +09:00
Bob Liu 10dc4155c7 mm: thp: cleanup: mv alloc_hugepage to better place
Move alloc_hugepage() to a better place, no need for a seperate #ifndef
CONFIG_NUMA

Signed-off-by: Bob Liu <bob.liu@oracle.com>
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andrew Davidoff <davidoff@qedmf.net>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:06 +09:00
Wanpeng Li b82225f3ff revert mm/vmalloc.c: emit the failure message before return
Don't warn twice in __vmalloc_area_node and __vmalloc_node_range if
__vmalloc_area_node allocation failure.  This patch reverts commit
46c001a275 ("mm/vmalloc.c: emit the failure message before return").

Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.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>
2013-11-13 12:09:05 +09:00
Wanpeng Li af12346cda mm/vmalloc: revert "mm/vmalloc.c: check VM_UNINITIALIZED flag in s_show instead of show_numa_info"
The VM_UNINITIALIZED/VM_UNLIST flag introduced by f5252e009d ("mm:
avoid null pointer access in vm_struct via /proc/vmallocinfo") is used
to avoid accessing the pages field with unallocated page when
show_numa_info() is called.

This patch moves the check just before show_numa_info in order that some
messages still can be dumped via /proc/vmallocinfo.  This patch reverts
commit d157a55815 ("mm/vmalloc.c: check VM_UNINITIALIZED flag in
s_show instead of show_numa_info");

Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Mitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.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>
2013-11-13 12:09:05 +09:00
Wanpeng Li c2ce8c142c mm/vmalloc: fix show vmap_area information race with vmap_area tear down
There is a race window between vmap_area tear down and show vmap_area
information.

	A                                                B

remove_vm_area
spin_lock(&vmap_area_lock);
va->vm = NULL;
va->flags &= ~VM_VM_AREA;
spin_unlock(&vmap_area_lock);
						spin_lock(&vmap_area_lock);
						if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEZING))
							return 0;
						if (!(va->flags & VM_VM_AREA)) {
							seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n",
								(void *)va->va_start, (void *)va->va_end,
								va->va_end - va->va_start);
							return 0;
						}
free_unmap_vmap_area(va);
	flush_cache_vunmap
	free_unmap_vmap_area_noflush
		unmap_vmap_area
		free_vmap_area_noflush
			va->flags |= VM_LAZY_FREE

The assumption !VM_VM_AREA represents vm_map_ram allocation is
introduced by d4033afdf8 ("mm, vmalloc: iterate vmap_area_list,
instead of vmlist, in vmallocinfo()").

However, !VM_VM_AREA also represents vmap_area is being tear down in
race window mentioned above.  This patch fix it by don't dump any
information for !VM_VM_AREA case and also remove (VM_LAZY_FREE |
VM_LAZY_FREEING) check since they are not possible for !VM_VM_AREA case.

Suggested-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Mitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.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>
2013-11-13 12:09:05 +09:00
Wanpeng Li 3722e13cff mm/vmalloc: don't set area->caller twice
The caller address has already been set in set_vmalloc_vm(), there's no
need to set it again in __vmalloc_area_node.

Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.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>
2013-11-13 12:09:05 +09:00
David Rientjes 948927ee9e mm, mempolicy: make mpol_to_str robust and always succeed
mpol_to_str() should not fail.  Currently, it either fails because the
string buffer is too small or because a string hasn't been defined for a
mempolicy mode.

If a new mempolicy mode is introduced and no string is defined for it,
just warn and return "unknown".

If the buffer is too small, just truncate the string and return, the
same behavior as snprintf().

This also fixes a bug where there was no NULL-byte termination when doing
*p++ = '=' and *p++ ':' and maxlen has been reached.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Chen Gang <gang.chen@asianux.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:05 +09:00
Naoya Horiguchi 03b61ff3c3 mm/memory-failure.c: move set_migratetype_isolate() outside get_any_page()
Chen Gong pointed out that set/unset_migratetype_isolate() was done in
different functions in mm/memory-failure.c, which makes the code less
readable/maintainable.  So this patch does it in soft_offline_page().

With this patch, we get to hold lock_memory_hotplug() longer but it's
not a problem because races between memory hotplug and soft offline are
very rare.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: Chen, Gong <gong.chen@linux.intel.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:04 +09:00
Toshi Kani 01b0f19707 cpu/mem hotplug: add try_online_node() for cpu_up()
cpu_up() has #ifdef CONFIG_MEMORY_HOTPLUG code blocks, which call
mem_online_node() to put its node online if offlined and then call
build_all_zonelists() to initialize the zone list.

These steps are specific to memory hotplug, and should be managed in
mm/memory_hotplug.c.  lock_memory_hotplug() should also be held for the
whole steps.

For this reason, this patch replaces mem_online_node() with
try_online_node(), which performs the whole steps with
lock_memory_hotplug() held.  try_online_node() is named after
try_offline_node() as they have similar purpose.

There is no functional change in this patch.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:04 +09:00
Robin Holt 309d0b3917 mm/nobootmem.c: have __free_pages_memory() free in larger chunks.
On large memory machines it can take a few minutes to get through
free_all_bootmem().

Currently, when free_all_bootmem() calls __free_pages_memory(), the number
of contiguous pages that __free_pages_memory() passes to the buddy
allocator is limited to BITS_PER_LONG.  BITS_PER_LONG was originally
chosen to keep things similar to mm/nobootmem.c.  But it is more efficient
to limit it to MAX_ORDER.

       base   new  change
8TB    202s  172s   30s
16TB   401s  351s   50s

That is around 1%-3% improvement on total boot time.

This patch was spun off from the boot time rfc Robin and I had been
working on.

Signed-off-by: Robin Holt <robin.m.holt@gmail.com>
Signed-off-by: Nathan Zimmer <nzimmer@sgi.com>
Cc: Robin Holt <robinmholt@linux.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mike Travis <travis@sgi.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:04 +09:00
Qiang Huang b9921ecdee mm: add a helper function to check may oom condition
Use helper function to check if we need to deal with oom condition.

Signed-off-by: Qiang Huang <h.huangqiang@huawei.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>
2013-11-13 12:09:04 +09:00
Xishi Qiu 9c2606b77d mm/memory_hotplug.c: use pfn_to_nid() instead of page_to_nid(pfn_to_page())
Use "pfn_to_nid(pfn)" instead of "page_to_nid(pfn_to_page(pfn))".

Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
Acked-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:04 +09:00
Xishi Qiu d6de9d5349 mm/memory_hotplug.c: rename the function is_memblock_offlined_cb()
A is_memblock_offlined() return or 1 means memory block is offlined, but
is_memblock_offlined_cb() returning 1 means memory block is not offlined,
this will confuse somebody, so rename the function.

Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
Acked-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:04 +09:00
Xishi Qiu b38a872596 mm: use populated_zone() instead of if(zone->present_pages)
Use "if (zone->present_pages)" instead of "if (zone->present_pages)".
Simplify the code, no functional change.

Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:04 +09:00
Xishi Qiu 83285c72e0 mm: use pgdat_end_pfn() to simplify the code in others
Use "pgdat_end_pfn()" instead of "pgdat->node_start_pfn +
pgdat->node_spanned_pages".  Simplify the code, no functional change.

Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:03 +09:00
Jianguo Wu 8bfa3f9a01 mm/huge_memory.c: fix stale comments of transparent_hugepage_flags
Since commit 13ece886d9 ("thp: transparent hugepage config choice"),
transparent hugepage support is disabled by default, and
TRANSPARENT_HUGEPAGE_ALWAYS is configured when TRANSPARENT_HUGEPAGE=y.

And since commit d39d33c332 ("thp: enable direct defrag"), defrag is
enable for all transparent hugepage page faults by default, not only in
MADV_HUGEPAGE regions.

Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:03 +09:00
Naoya Horiguchi c69ded84a9 mm: remove obsolete comments about page table lock
The callers of free_pgd_range() and hugetlb_free_pgd_range() don't hold
page table locks.  The comments seems to be obsolete, so let's remove
them.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:03 +09:00
Jerome Marchand 9e4be4708e mm/compaction.c: update comment about zone lock in isolate_freepages_block
Since commit f40d1e42bb ("mm: compaction: acquire the zone->lock as
late as possible"), isolate_freepages_block() takes the zone->lock
itself.  The function description however still states that the
zone->lock must be held.

This patch removes this outdated statement.

Signed-off-by: Jerome Marchand <jmarchan@redhat.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>
2013-11-13 12:09:03 +09:00
Jianguo Wu 4b90951c0b mm/vmalloc: use NUMA_NO_NODE
Use more appropriate "if (node == NUMA_NO_NODE)" instead of "if (node < 0)"

Signed-off-by: Jianguo Wu <wujianguo@huawei.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>
2013-11-13 12:09:02 +09:00
Joe Perches bafe1e1440 ksm: remove redundant __GFP_ZERO from kcalloc
kcalloc returns zeroed memory.  There's no need to use this flag.

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:02 +09:00
Andrew Morton 63d0f0a3c7 mm/readahead.c:do_readhead(): don't check for ->readpage
The callee force_page_cache_readahead() already does this and unlike
do_readahead(), force_page_cache_readahead() remembers to check for
->readpages() as well.

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:02 +09:00
Linus Torvalds 39cf275a1a Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler changes from Ingo Molnar:
 "The main changes in this cycle are:

   - (much) improved CONFIG_NUMA_BALANCING support from Mel Gorman, Rik
     van Riel, Peter Zijlstra et al.  Yay!

   - optimize preemption counter handling: merge the NEED_RESCHED flag
     into the preempt_count variable, by Peter Zijlstra.

   - wait.h fixes and code reorganization from Peter Zijlstra

   - cfs_bandwidth fixes from Ben Segall

   - SMP load-balancer cleanups from Peter Zijstra

   - idle balancer improvements from Jason Low

   - other fixes and cleanups"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (129 commits)
  ftrace, sched: Add TRACE_FLAG_PREEMPT_RESCHED
  stop_machine: Fix race between stop_two_cpus() and stop_cpus()
  sched: Remove unnecessary iteration over sched domains to update nr_busy_cpus
  sched: Fix asymmetric scheduling for POWER7
  sched: Move completion code from core.c to completion.c
  sched: Move wait code from core.c to wait.c
  sched: Move wait.c into kernel/sched/
  sched/wait: Fix __wait_event_interruptible_lock_irq_timeout()
  sched: Avoid throttle_cfs_rq() racing with period_timer stopping
  sched: Guarantee new group-entities always have weight
  sched: Fix hrtimer_cancel()/rq->lock deadlock
  sched: Fix cfs_bandwidth misuse of hrtimer_expires_remaining
  sched: Fix race on toggling cfs_bandwidth_used
  sched: Remove extra put_online_cpus() inside sched_setaffinity()
  sched/rt: Fix task_tick_rt() comment
  sched/wait: Fix build breakage
  sched/wait: Introduce prepare_to_wait_event()
  sched/wait: Add ___wait_cond_timeout() to wait_event*_timeout() too
  sched: Remove get_online_cpus() usage
  sched: Fix race in migrate_swap_stop()
  ...
2013-11-12 10:20:12 +09:00
Mikulas Patocka 8077c0d983 bdi: test bdi_init failure
There were two places where return value from bdi_init was not tested.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-11-08 08:59:44 -07:00
John Stultz 1ca7d67cf5 seqcount: Add lockdep functionality to seqcount/seqlock structures
Currently seqlocks and seqcounts don't support lockdep.

After running across a seqcount related deadlock in the timekeeping
code, I used a less-refined and more focused variant of this patch
to narrow down the cause of the issue.

This is a first-pass attempt to properly enable lockdep functionality
on seqlocks and seqcounts.

Since seqcounts are used in the vdso gettimeofday code, I've provided
non-lockdep accessors for those needs.

I've also handled one case where there were nested seqlock writers
and there may be more edge cases.

Comments and feedback would be appreciated!

Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/1381186321-4906-3-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 12:40:26 +01:00
Ingo Molnar c90423d1de Merge branch 'sched/core' into core/locking, to prepare the kernel/locking/ file move
Conflicts:
	kernel/Makefile

There are conflicts in kernel/Makefile due to file moving in the
scheduler tree - resolve them.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06 07:50:37 +01:00
David S. Miller 394efd19d5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/emulex/benet/be.h
	drivers/net/netconsole.c
	net/bridge/br_private.h

Three mostly trivial conflicts.

The net/bridge/br_private.h conflict was a function signature (argument
addition) change overlapping with the extern removals from Joe Perches.

In drivers/net/netconsole.c we had one change adjusting a printk message
whilst another changed "printk(KERN_INFO" into "pr_info(".

Lastly, the emulex change was a new inline function addition overlapping
with Joe Perches's extern removals.

Signed-off-by: David S. Miller <davem@davemloft.net>
2013-11-04 13:48:30 -05:00
Greg Thelen 6920a1bd03 memcg: remove incorrect underflow check
When a memcg is deleted mem_cgroup_reparent_charges() moves charged
memory to the parent memcg.  As of v3.11-9444-g3ea67d0 "memcg: add per
cgroup writeback pages accounting" there's bad pointer read.  The goal
was to check for counter underflow.  The counter is a per cpu counter
and there are two problems with the code:

 (1) per cpu access function isn't used, instead a naked pointer is used
     which easily causes oops.
 (2) the check doesn't sum all cpus

Test:
  $ cd /sys/fs/cgroup/memory
  $ mkdir x
  $ echo 3 > /proc/sys/vm/drop_caches
  $ (echo $BASHPID >> x/tasks && exec cat) &
  [1] 7154
  $ grep ^mapped x/memory.stat
  mapped_file 53248
  $ echo 7154 > tasks
  $ rmdir x
  <OOPS>

The fix is to remove the check.  It's currently dangerous and isn't
worth fixing it to use something expensive, such as
percpu_counter_sum(), for each reparented page.  __this_cpu_read() isn't
enough to fix this because there's no guarantees of the current cpus
count.  The only guarantees is that the sum of all per-cpu counter is >=
nr_pages.

Fixes: 3ea67d06e4 ("memcg: add per cgroup writeback pages accounting")
Reported-and-tested-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: Greg Thelen <gthelen@google.com>
Reviewed-by: Sha Zhengju <handai.szj@taobao.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-01 12:22:28 -07:00
Ingo Molnar fb10d5b7ef Merge branch 'linus' into sched/core
Resolve cherry-picking conflicts:

Conflicts:
	mm/huge_memory.c
	mm/memory.c
	mm/mprotect.c

See this upstream merge commit for more details:

  52469b4fcd Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-01 08:24:41 +01:00
Linus Torvalds 4f794ee8c4 Merge branch 'akpm' (fixes from Andrew Morton)
Merge four more fixes from Andrew Morton.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  lib/scatterlist.c: don't flush_kernel_dcache_page on slab page
  mm: memcg: fix test for child groups
  mm: memcg: lockdep annotation for memcg OOM lock
  mm: memcg: use proper memcg in limit bypass
2013-10-31 16:58:23 -07:00
Johannes Weiner 696ac172ff mm: memcg: fix test for child groups
When memcg code needs to know whether any given memcg has children, it
uses the cgroup child iteration primitives and returns true/false
depending on whether the iteration loop is executed at least once or
not.

Because a cgroup's list of children is RCU protected, these primitives
require the RCU read-lock to be held, which is not the case for all
memcg callers.  This results in the following splat when e.g.  enabling
hierarchy mode:

  WARNING: CPU: 3 PID: 1 at kernel/cgroup.c:3043 css_next_child+0xa3/0x160()
  CPU: 3 PID: 1 Comm: systemd Not tainted 3.12.0-rc5-00117-g83f11a9-dirty #18
  Hardware name: LENOVO 3680B56/3680B56, BIOS 6QET69WW (1.39 ) 04/26/2012
  Call Trace:
    dump_stack+0x54/0x74
    warn_slowpath_common+0x78/0xa0
    warn_slowpath_null+0x1a/0x20
    css_next_child+0xa3/0x160
    mem_cgroup_hierarchy_write+0x5b/0xa0
    cgroup_file_write+0x108/0x2a0
    vfs_write+0xbd/0x1e0
    SyS_write+0x4c/0xa0
    system_call_fastpath+0x16/0x1b

In the memcg case, we only care about children when we are attempting to
modify inheritable attributes interactively.  Racing with deletion could
mean a spurious -EBUSY, no problem.  Racing with addition is handled
just fine as well through the memcg_create_mutex: if the child group is
not on the list after the mutex is acquired, it won't be initialized
from the parent's attributes until after the unlock.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-31 16:58:13 -07:00
Johannes Weiner 0056f4e66a mm: memcg: lockdep annotation for memcg OOM lock
The memcg OOM lock is a mutex-type lock that is open-coded due to
memcg's special needs.  Add annotations for lockdep coverage.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-31 16:58:13 -07:00
Johannes Weiner 3168ecbe1c mm: memcg: use proper memcg in limit bypass
Commit 84235de394 ("fs: buffer: move allocation failure loop into the
allocator") allowed __GFP_NOFAIL allocations to bypass the limit if they
fail to reclaim enough memory for the charge.  But because the main test
case was on a 3.2-based system, the patch missed the fact that on newer
kernels the charge function needs to return root_mem_cgroup when
bypassing the limit, and not NULL.  This will corrupt whatever memory is
at NULL + percpu pointer offset.  Fix this quickly before problems are
reported.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-31 16:58:13 -07:00
Linus Torvalds 52469b4fcd Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull NUMA balancing memory corruption fixes from Ingo Molnar:
 "So these fixes are definitely not something I'd like to sit on, but as
  I said to Mel at the KS the timing is quite tight, with Linus planning
  v3.12-final within a week.

  Fedora-19 is affected:

   comet:~> grep NUMA_BALANCING /boot/config-3.11.3-201.fc19.x86_64

   CONFIG_ARCH_SUPPORTS_NUMA_BALANCING=y
   CONFIG_NUMA_BALANCING_DEFAULT_ENABLED=y
   CONFIG_NUMA_BALANCING=y

  AFAICS Ubuntu will be affected as well, once it updates the kernel:

   hubble:~> grep NUMA_BALANCING /boot/config-3.8.0-32-generic

   CONFIG_ARCH_SUPPORTS_NUMA_BALANCING=y
   CONFIG_NUMA_BALANCING_DEFAULT_ENABLED=y
   CONFIG_NUMA_BALANCING=y

  These 6 commits are a minimalized set of cherry-picks needed to fix
  the memory corruption bugs.  All commits are fixes, except "mm: numa:
  Sanitize task_numa_fault() callsites" which is a cleanup that made two
  followup fixes simpler.

  I've done targeted testing with just this SHA1 to try to make sure
  there are no cherry-picking artifacts.  The original non-cherry-picked
  set of fixes were exposed to linux-next for a couple of weeks"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  mm: Account for a THP NUMA hinting update as one PTE update
  mm: Close races between THP migration and PMD numa clearing
  mm: numa: Sanitize task_numa_fault() callsites
  mm: Prevent parallel splits during THP migration
  mm: Wait for THP migrations to complete during NUMA hinting faults
  mm: numa: Do not account for a hinting fault if we raced
2013-10-31 15:21:26 -07:00
Linus Torvalds 12aee278b5 Merge branch 'akpm' (fixes from Andrew Morton)
Merge three fixes from Andrew Morton.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  memcg: use __this_cpu_sub() to dec stats to avoid incorrect subtrahend casting
  percpu: fix this_cpu_sub() subtrahend casting for unsigneds
  mm/pagewalk.c: fix walk_page_range() access of wrong PTEs
2013-10-30 14:27:10 -07:00
Greg Thelen 5e8cfc3c75 memcg: use __this_cpu_sub() to dec stats to avoid incorrect subtrahend casting
As of commit 3ea67d06e4 ("memcg: add per cgroup writeback pages
accounting") memcg counter errors are possible when moving charged
memory to a different memcg.  Charge movement occurs when processing
writes to memory.force_empty, moving tasks to a memcg with
memcg.move_charge_at_immigrate=1, or memcg deletion.

An example showing error after memory.force_empty:

  $ cd /sys/fs/cgroup/memory
  $ mkdir x
  $ rm /data/tmp/file
  $ (echo $BASHPID >> x/tasks && exec mmap_writer /data/tmp/file 1M) &
  [1] 13600
  $ grep ^mapped x/memory.stat
  mapped_file 1048576
  $ echo 13600 > tasks
  $ echo 1 > x/memory.force_empty
  $ grep ^mapped x/memory.stat
  mapped_file 4503599627370496

mapped_file should end with 0.
  4503599627370496 == 0x10,0000,0000,0000 == 0x100,0000,0000 pages
  1048576          == 0x10,0000           == 0x100 pages

This issue only affects the source memcg on 64 bit machines; the
destination memcg counters are correct.  So the rmdir case is not too
important because such counters are soon disappearing with the entire
memcg.  But the memcg.force_empty and memory.move_charge_at_immigrate=1
cases are larger problems as the bogus counters are visible for the
(possibly long) remaining life of the source memcg.

The problem is due to memcg use of __this_cpu_from(.., -nr_pages), which
is subtly wrong because it subtracts the unsigned int nr_pages (either
-1 or -512 for THP) from a signed long percpu counter.  When
nr_pages=-1, -nr_pages=0xffffffff.  On 64 bit machines stat->count[idx]
is signed 64 bit.  So memcg's attempt to simply decrement a count (e.g.
from 1 to 0) boils down to:

  long count = 1
  unsigned int nr_pages = 1
  count += -nr_pages  /* -nr_pages == 0xffff,ffff */
  count is now 0x1,0000,0000 instead of 0

The fix is to subtract the unsigned page count rather than adding its
negation.  This only works once "percpu: fix this_cpu_sub() subtrahend
casting for unsigneds" is applied to fix this_cpu_sub().

Signed-off-by: Greg Thelen <gthelen@google.com>
Acked-by: Tejun Heo <tj@kernel.org>
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>
2013-10-30 14:27:03 -07:00
Chen LinX 3017f079ef mm/pagewalk.c: fix walk_page_range() access of wrong PTEs
When walk_page_range walk a memory map's page tables, it'll skip
VM_PFNMAP area, then variable 'next' will to assign to vma->vm_end, it
maybe larger than 'end'.  In next loop, 'addr' will be larger than
'next'.  Then in /proc/XXXX/pagemap file reading procedure, the 'addr'
will growing forever in pagemap_pte_range, pte_to_pagemap_entry will
access the wrong pte.

  BUG: Bad page map in process procrank  pte:8437526f pmd:785de067
  addr:9108d000 vm_flags:00200073 anon_vma:f0d99020 mapping:  (null) index:9108d
  CPU: 1 PID: 4974 Comm: procrank Tainted: G    B   W  O 3.10.1+ #1
  Call Trace:
    dump_stack+0x16/0x18
    print_bad_pte+0x114/0x1b0
    vm_normal_page+0x56/0x60
    pagemap_pte_range+0x17a/0x1d0
    walk_page_range+0x19e/0x2c0
    pagemap_read+0x16e/0x200
    vfs_read+0x84/0x150
    SyS_read+0x4a/0x80
    syscall_call+0x7/0xb

Signed-off-by: Liu ShuoX <shuox.liu@intel.com>
Signed-off-by: Chen LinX <linx.z.chen@intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: <stable@vger.kernel.org>	[3.10.x+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-30 14:27:03 -07:00
Russell King c56b097af2 mm: list_lru: fix almost infinite loop causing effective livelock
I've seen a fair number of issues with kswapd and other processes
appearing to get stuck in v3.12-rc.  Using sysrq-p many times seems to
indicate that it gets stuck somewhere in list_lru_walk_node(), called
from prune_icache_sb() and super_cache_scan().

I never seem to be able to trigger a calltrace for functions above that
point.

So I decided to add the following to super_cache_scan():

    @@ -81,10 +81,14 @@ static unsigned long super_cache_scan(struct shrinker *shrink,
            inodes = list_lru_count_node(&sb->s_inode_lru, sc->nid);
            dentries = list_lru_count_node(&sb->s_dentry_lru, sc->nid);
            total_objects = dentries + inodes + fs_objects + 1;
    +printk("%s:%u: %s: dentries %lu inodes %lu total %lu\n", current->comm, current->pid, __func__, dentries, inodes, total_objects);

            /* proportion the scan between the caches */
            dentries = mult_frac(sc->nr_to_scan, dentries, total_objects);
            inodes = mult_frac(sc->nr_to_scan, inodes, total_objects);
    +printk("%s:%u: %s: dentries %lu inodes %lu\n", current->comm, current->pid, __func__, dentries, inodes);
    +BUG_ON(dentries == 0);
    +BUG_ON(inodes == 0);

            /*
             * prune the dcache first as the icache is pinned by it, then
    @@ -99,7 +103,7 @@ static unsigned long super_cache_scan(struct shrinker *shrink,
                    freed += sb->s_op->free_cached_objects(sb, fs_objects,
                                                           sc->nid);
            }
    -
    +printk("%s:%u: %s: dentries %lu inodes %lu freed %lu\n", current->comm, current->pid, __func__, dentries, inodes, freed);
            drop_super(sb);
            return freed;
     }

and shortly thereafter, having applied some pressure, I got this:

    update-apt-xapi:1616: super_cache_scan: dentries 25632 inodes 2 total 25635
    update-apt-xapi:1616: super_cache_scan: dentries 1023 inodes 0
    ------------[ cut here ]------------
    Kernel BUG at c0101994 [verbose debug info unavailable]
    Internal error: Oops - BUG: 0 [#3] SMP ARM
    Modules linked in: fuse rfcomm bnep bluetooth hid_cypress
    CPU: 0 PID: 1616 Comm: update-apt-xapi Tainted: G      D      3.12.0-rc7+ #154
    task: daea1200 ti: c3bf8000 task.ti: c3bf8000
    PC is at super_cache_scan+0x1c0/0x278
    LR is at trace_hardirqs_on+0x14/0x18
    Process update-apt-xapi (pid: 1616, stack limit = 0xc3bf8240)
    ...
    Backtrace:
      (super_cache_scan) from [<c00cd69c>] (shrink_slab+0x254/0x4c8)
      (shrink_slab) from [<c00d09a0>] (try_to_free_pages+0x3a0/0x5e0)
      (try_to_free_pages) from [<c00c59cc>] (__alloc_pages_nodemask+0x5)
      (__alloc_pages_nodemask) from [<c00e07c0>] (__pte_alloc+0x2c/0x13)
      (__pte_alloc) from [<c00e3a70>] (handle_mm_fault+0x84c/0x914)
      (handle_mm_fault) from [<c001a4cc>] (do_page_fault+0x1f0/0x3bc)
      (do_page_fault) from [<c001a7b0>] (do_translation_fault+0xac/0xb8)
      (do_translation_fault) from [<c000840c>] (do_DataAbort+0x38/0xa0)
      (do_DataAbort) from [<c00133f8>] (__dabt_usr+0x38/0x40)

Notice that we had a very low number of inodes, which were reduced to
zero my mult_frac().

Now, prune_icache_sb() calls list_lru_walk_node() passing that number of
inodes (0) into that as the number of objects to scan:

    long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan,
                         int nid)
    {
            LIST_HEAD(freeable);
            long freed;

            freed = list_lru_walk_node(&sb->s_inode_lru, nid, inode_lru_isolate,
                                           &freeable, &nr_to_scan);

which does:

    unsigned long
    list_lru_walk_node(struct list_lru *lru, int nid, list_lru_walk_cb isolate,
                       void *cb_arg, unsigned long *nr_to_walk)
    {

            struct list_lru_node    *nlru = &lru->node[nid];
            struct list_head *item, *n;
            unsigned long isolated = 0;

            spin_lock(&nlru->lock);
    restart:
            list_for_each_safe(item, n, &nlru->list) {
                    enum lru_status ret;

                    /*
                     * decrement nr_to_walk first so that we don't livelock if we
                     * get stuck on large numbesr of LRU_RETRY items
                     */
                    if (--(*nr_to_walk) == 0)
                            break;

So, if *nr_to_walk was zero when this function was entered, that means
we're wanting to operate on (~0UL)+1 objects - which might as well be
infinite.

Clearly this is not correct behaviour.  If we think about the behaviour
of this function when *nr_to_walk is 1, then clearly it's wrong - we
decrement first and then test for zero - which results in us doing
nothing at all.  A post-decrement would give the desired behaviour -
we'd try to walk one object and one object only if *nr_to_walk were one.

It also gives the correct behaviour for zero - we exit at this point.

Fixes: 5cedf721a7 ("list_lru: fix broken LRU_RETRY behaviour")
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
[ Modified to make sure we never underflow the count: this function gets
  called in a loop, so the 0 -> ~0ul transition is dangerous  - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-30 12:57:46 -07:00
Mel Gorman 0255d49184 mm: Account for a THP NUMA hinting update as one PTE update
A THP PMD update is accounted for as 512 pages updated in vmstat.  This is
large difference when estimating the cost of automatic NUMA balancing and
can be misleading when comparing results that had collapsed versus split
THP. This patch addresses the accounting issue.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-10-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29 11:38:17 +01:00
Mel Gorman 3f926ab945 mm: Close races between THP migration and PMD numa clearing
THP migration uses the page lock to guard against parallel allocations
but there are cases like this still open

  Task A					Task B
  ---------------------				---------------------
  do_huge_pmd_numa_page				do_huge_pmd_numa_page
  lock_page
  mpol_misplaced == -1
  unlock_page
  goto clear_pmdnuma
						lock_page
						mpol_misplaced == 2
						migrate_misplaced_transhuge
  pmd = pmd_mknonnuma
  set_pmd_at

During hours of testing, one crashed with weird errors and while I have
no direct evidence, I suspect something like the race above happened.
This patch extends the page lock to being held until the pmd_numa is
cleared to prevent migration starting in parallel while the pmd_numa is
being cleared. It also flushes the old pmd entry and orders pagetable
insertion before rmap insertion.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-9-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29 11:38:05 +01:00
Mel Gorman c61109e34f mm: numa: Sanitize task_numa_fault() callsites
There are three callers of task_numa_fault():

 - do_huge_pmd_numa_page():
     Accounts against the current node, not the node where the
     page resides, unless we migrated, in which case it accounts
     against the node we migrated to.

 - do_numa_page():
     Accounts against the current node, not the node where the
     page resides, unless we migrated, in which case it accounts
     against the node we migrated to.

 - do_pmd_numa_page():
     Accounts not at all when the page isn't migrated, otherwise
     accounts against the node we migrated towards.

This seems wrong to me; all three sites should have the same
sementaics, furthermore we should accounts against where the page
really is, we already know where the task is.

So modify all three sites to always account; we did after all receive
the fault; and always account to where the page is after migration,
regardless of success.

They all still differ on when they clear the PTE/PMD; ideally that
would get sorted too.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-8-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29 11:37:52 +01:00
Mel Gorman 587fe586f4 mm: Prevent parallel splits during THP migration
THP migrations are serialised by the page lock but on its own that does
not prevent THP splits. If the page is split during THP migration then
the pmd_same checks will prevent page table corruption but the unlock page
and other fix-ups potentially will cause corruption. This patch takes the
anon_vma lock to prevent parallel splits during migration.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-7-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29 11:37:39 +01:00
Mel Gorman 42836f5f8b mm: Wait for THP migrations to complete during NUMA hinting faults
The locking for migrating THP is unusual. While normal page migration
prevents parallel accesses using a migration PTE, THP migration relies on
a combination of the page_table_lock, the page lock and the existance of
the NUMA hinting PTE to guarantee safety but there is a bug in the scheme.

If a THP page is currently being migrated and another thread traps a
fault on the same page it checks if the page is misplaced. If it is not,
then pmd_numa is cleared. The problem is that it checks if the page is
misplaced without holding the page lock meaning that the racing thread
can be migrating the THP when the second thread clears the NUMA bit
and faults a stale page.

This patch checks if the page is potentially being migrated and stalls
using the lock_page if it is potentially being migrated before checking
if the page is misplaced or not.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-6-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29 11:37:19 +01:00
Mel Gorman 1dd49bfa34 mm: numa: Do not account for a hinting fault if we raced
If another task handled a hinting fault in parallel then do not double
account for it.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-5-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-29 11:37:05 +01:00
Al Viro 72c2d53192 file->f_op is never NULL...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-10-24 23:34:54 -04:00
David S. Miller c3fa32b976 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/usb/qmi_wwan.c
	include/net/dst.h

Trivial merge conflicts, both were overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-23 16:49:34 -04:00
Eric W. Biederman 2e685cad57 tcp_memcontrol: Kill struct tcp_memcontrol
Replace the pointers in struct cg_proto with actual data fields and kill
struct tcp_memcontrol as it is not fully redundant.

This removes a confusing, unnecessary layer of abstraction.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-21 18:43:02 -04:00
Xie XiuQi d175617436 mm: Fix some trivial typos in comments
Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-10-18 14:49:53 +02:00
Hugh Dickins 57a8f0cdb8 mm: revert mremap pud_free anti-fix
Revert commit 1ecfd533f4 ("mm/mremap.c: call pud_free() after fail
calling pmd_alloc()").

The original code was correct: pud_alloc(), pmd_alloc(), pte_alloc_map()
ensure that the pud, pmd, pt is already allocated, and seldom do they
need to allocate; on failure, upper levels are freed if appropriate by
the subsequent do_munmap().  Whereas commit 1ecfd533f4 did an
unconditional pud_free() of a most-likely still-in-use pud: saved only
by the near-impossiblity of pmd_alloc() failing.

Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-16 21:35:53 -07:00
Hugh Dickins 750e8165f5 mm: fix BUG in __split_huge_page_pmd
Occasionally we hit the BUG_ON(pmd_trans_huge(*pmd)) at the end of
__split_huge_page_pmd(): seen when doing madvise(,,MADV_DONTNEED).

It's invalid: we don't always have down_write of mmap_sem there: a racing
do_huge_pmd_wp_page() might have copied-on-write to another huge page
before our split_huge_page() got the anon_vma lock.

Forget the BUG_ON, just go back and try again if this happens.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.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>
2013-10-16 21:35:53 -07:00
Krzysztof Kozlowski 5b808a2300 swap: fix set_blocksize race during swapon/swapoff
Fix race between swapoff and swapon.  Swapoff used old_block_size from
swap_info outside of swapon_mutex so it could be overwritten by
concurrent swapon.

The race has visible effect only if more than one swap block device
exists with different block sizes (e.g.  /dev/sda1 with block size 4096
and /dev/sdb1 with 512).  In such case it leads to setting the blocksize
of swapped off device with wrong blocksize.

The bug can be triggered with multiple concurrent swapoff and swapon:
0. Swap for some device is on.
1. swapoff:
First the swapoff is called on this device and "struct swap_info_struct
*p" is assigned. This is done under swap_lock however this lock is
released for the call try_to_unuse().

2. swapon:
After the assignment above (and before acquiring swapon_mutex &
swap_lock by swapoff) the swapon is called on the same device.
The p->old_block_size is assigned to the value of block_size the device.
This block size should be the same as previous but sometimes it is not.
The swapon ends successfully.

3. swapoff:
Swapoff resumes, grabs the locks and mutex and continues to disable this
swap device. Now it sets the block size to value taken from swap_info
which was overwritten by swapon in 2.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reported-by: Weijie Yang <weijie.yang.kh@gmail.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Shaohua Li <shli@fusionio.com>
Cc: Minchan Kim <minchan@kernel.org>
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>
2013-10-16 21:35:53 -07:00
Fengguang Wu e3b6c655b9 writeback: fix negative bdi max pause
Toralf runs trinity on UML/i386.  After some time it hangs and the last
message line is

	BUG: soft lockup - CPU#0 stuck for 22s! [trinity-child0:1521]

It's found that pages_dirtied becomes very large.  More than 1000000000
pages in this case:

	period = HZ * pages_dirtied / task_ratelimit;
	BUG_ON(pages_dirtied > 2000000000);
	BUG_ON(pages_dirtied > 1000000000);      <---------

UML debug printf shows that we got negative pause here:

	ick: pause : -984
	ick: pages_dirtied : 0
	ick: task_ratelimit: 0

	 pause:
	+       if (pause < 0)  {
	+               extern int printf(char *, ...);
	+               printf("ick : pause : %li\n", pause);
	+               printf("ick: pages_dirtied : %lu\n", pages_dirtied);
	+               printf("ick: task_ratelimit: %lu\n", task_ratelimit);
	+               BUG_ON(1);
	+       }
	        trace_balance_dirty_pages(bdi,

Since pause is bounded by [min_pause, max_pause] where min_pause is also
bounded by max_pause.  It's suspected and demonstrated that the
max_pause calculation goes wrong:

	ick: pause : -717
	ick: min_pause : -177
	ick: max_pause : -717
	ick: pages_dirtied : 14
	ick: task_ratelimit: 0

The problem lies in the two "long = unsigned long" assignments in
bdi_max_pause() which might go negative if the highest bit is 1, and the
min_t(long, ...) check failed to protect it falling under 0.  Fix all of
them by using "unsigned long" throughout the function.

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Tested-by: Toralf Förster <toralf.foerster@gmx.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Richard Weinberger <richard@nod.at>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-16 21:35:53 -07:00
Johannes Weiner 84235de394 fs: buffer: move allocation failure loop into the allocator
Buffer allocation has a very crude indefinite loop around waking the
flusher threads and performing global NOFS direct reclaim because it can
not handle allocation failures.

The most immediate problem with this is that the allocation may fail due
to a memory cgroup limit, where flushers + direct reclaim might not make
any progress towards resolving the situation at all.  Because unlike the
global case, a memory cgroup may not have any cache at all, only
anonymous pages but no swap.  This situation will lead to a reclaim
livelock with insane IO from waking the flushers and thrashing unrelated
filesystem cache in a tight loop.

Use __GFP_NOFAIL allocations for buffers for now.  This makes sure that
any looping happens in the page allocator, which knows how to
orchestrate kswapd, direct reclaim, and the flushers sensibly.  It also
allows memory cgroups to detect allocations that can't handle failure
and will allow them to ultimately bypass the limit if reclaim can not
make progress.

Reported-by: azurIt <azurit@pobox.sk>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-16 21:35:53 -07:00
Johannes Weiner 4942642080 mm: memcg: handle non-error OOM situations more gracefully
Commit 3812c8c8f3 ("mm: memcg: do not trap chargers with full
callstack on OOM") assumed that only a few places that can trigger a
memcg OOM situation do not return VM_FAULT_OOM, like optional page cache
readahead.  But there are many more and it's impractical to annotate
them all.

First of all, we don't want to invoke the OOM killer when the failed
allocation is gracefully handled, so defer the actual kill to the end of
the fault handling as well.  This simplifies the code quite a bit for
added bonus.

Second, since a failed allocation might not be the abrupt end of the
fault, the memcg OOM handler needs to be re-entrant until the fault
finishes for subsequent allocation attempts.  If an allocation is
attempted after the task already OOMed, allow it to bypass the limit so
that it can quickly finish the fault and invoke the OOM killer.

Reported-by: azurIt <azurit@pobox.sk>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-16 21:35:53 -07:00
Andrea Arcangeli ef5a22be2c mm: hugetlb: initialize PG_reserved for tail pages of gigantic compound pages
Commit 11feeb4980 ("kvm: optimize away THP checks in
kvm_is_mmio_pfn()") introduced a memory leak when KVM is run on gigantic
compound pages.

That commit depends on the assumption that PG_reserved is identical for
all head and tail pages of a compound page.  So that if get_user_pages
returns a tail page, we don't need to check the head page in order to
know if we deal with a reserved page that requires different
refcounting.

The assumption that PG_reserved is the same for head and tail pages is
certainly correct for THP and regular hugepages, but gigantic hugepages
allocated through bootmem don't clear the PG_reserved on the tail pages
(the clearing of PG_reserved is done later only if the gigantic hugepage
is freed).

This patch corrects the gigantic compound page initialization so that we
can retain the optimization in 11feeb4980.  The cacheline was already
modified in order to set PG_tail so this won't affect the boot time of
large memory systems.

[akpm@linux-foundation.org: tweak comment layout and grammar]
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: andy123 <ajs124.ajs124@gmail.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Acked-by: Rafael Aquini <aquini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-16 21:35:52 -07:00
Weijie Yang aa9bca05a4 mm/zswap: bugfix: memory leak when re-swapon
zswap_tree is not freed when swapoff, and it got re-kmalloced in swapon,
so a memory leak occurs.

Free the memory of zswap_tree in zswap_frontswap_invalidate_area().

Signed-off-by: Weijie Yang <weijie.yang@samsung.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>
From: Weijie Yang <weijie.yang@samsung.com>
Subject: mm/zswap: bugfix: memory leak when invalidate and reclaim occur concurrently

Consider the following scenario:
thread 0: reclaim entry x (get refcount, but not call zswap_get_swap_cache_page)
thread 1: call zswap_frontswap_invalidate_page to invalidate entry x.
	finished, entry x and its zbud is not freed as its refcount != 0
	now, the swap_map[x] = 0
thread 0: now call zswap_get_swap_cache_page
	swapcache_prepare return -ENOENT because entry x is not used any more
	zswap_get_swap_cache_page return ZSWAP_SWAPCACHE_NOMEM
	zswap_writeback_entry do nothing except put refcount
Now, the memory of zswap_entry x and its zpage leak.

Modify:
 - check the refcount in fail path, free memory if it is not referenced.

 - use ZSWAP_SWAPCACHE_FAIL instead of ZSWAP_SWAPCACHE_NOMEM as the fail path
   can be not only caused by nomem but also by invalidate.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Weijie Yang <weijie.yang@samsung.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>
Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-16 21:35:52 -07:00
Cyrill Gorcunov c3d16e1652 mm: migration: do not lose soft dirty bit if page is in migration state
If page migration is turned on in config and the page is migrating, we
may lose the soft dirty bit.  If fork and mprotect are called on
migrating pages (once migration is complete) pages do not obtain the
soft dirty bit in the correspond pte entries.  Fix it adding an
appropriate test on swap entries.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-16 21:35:52 -07:00
Joonsoo Kim 16c794b4f3 mm/hugetlb.c: correct missing private flag clearing
We should clear the page's private flag when returing the page to the
hugepage pool.  Otherwise, marked hugepage can be allocated to the user
who tries to allocate the non-reserved hugepage.  If this user fail to
map this hugepage, he would try to return the page to the hugepage pool.
Since this page has a private flag, resv_huge_pages would mistakenly
increase.  This patch fixes this situation.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.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>
2013-10-16 21:35:52 -07:00
Andrew Vagin ae39332162 mm/vmscan.c: don't forget to free shrinker->nr_deferred
This leak was added by commit 1d3d4437ea ("vmscan: per-node deferred
work").

unreferenced object 0xffff88006ada3bd0 (size 8):
  comm "criu", pid 14781, jiffies 4295238251 (age 105.641s)
  hex dump (first 8 bytes):
    00 00 00 00 00 00 00 00                          ........
  backtrace:
    [<ffffffff8170caee>] kmemleak_alloc+0x5e/0xc0
    [<ffffffff811c0527>] __kmalloc+0x247/0x310
    [<ffffffff8117848c>] register_shrinker+0x3c/0xa0
    [<ffffffff811e115b>] sget+0x5ab/0x670
    [<ffffffff812532f4>] proc_mount+0x54/0x170
    [<ffffffff811e1893>] mount_fs+0x43/0x1b0
    [<ffffffff81202dd2>] vfs_kern_mount+0x72/0x110
    [<ffffffff81202e89>] kern_mount_data+0x19/0x30
    [<ffffffff812530a0>] pid_ns_prepare_proc+0x20/0x40
    [<ffffffff81083c56>] alloc_pid+0x466/0x4a0
    [<ffffffff8105aeda>] copy_process+0xc6a/0x1860
    [<ffffffff8105beab>] do_fork+0x8b/0x370
    [<ffffffff8105c1a6>] SyS_clone+0x16/0x20
    [<ffffffff8171f739>] stub_clone+0x69/0x90
    [<ffffffffffffffff>] 0xffffffffffffffff

Signed-off-by: Andrew Vagin <avagin@openvz.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Glauber Costa <glommer@openvz.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-16 21:35:52 -07:00
David Rientjes 9c56751271 mm, memcg: protect mem_cgroup_read_events for cpu hotplug
for_each_online_cpu() needs the protection of {get,put}_online_cpus() so
cpu_online_mask doesn't change during the iteration.

cpu_hotplug.lock is held while a cpu is going down, it's a coarse lock
that is used kernel-wide to synchronize cpu hotplug activity.  Memcg has
a cpu hotplug notifier, called while there may not be any cpu hotplug
refcounts, which drains per-cpu event counts to memcg->nocpu_base.events
to maintain a cumulative event count as cpus disappear.  Without
get_online_cpus() in mem_cgroup_read_events(), it's possible to account
for the event count on a dying cpu twice, and this value may be
significantly large.

In fact, all memcg->pcp_counter_lock use should be nested by
{get,put}_online_cpus().

This fixes that issue and ensures the reported statistics are not vastly
over-reported during cpu hotplug.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-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>
2013-10-16 21:35:52 -07:00
Linus Torvalds 4b60667a06 Merge branch 'slab/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux
Pull SLAB fix from Pekka Enberg:
 "A regression fix for overly eager slab cache name checks"

* 'slab/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux:
  slab_common: Do not check for duplicate slab names
2013-10-14 10:00:36 -07:00
Geert Uytterhoeven 18f6533277 mm/Kconfig: Grammar s/an/a/
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-10-14 15:37:58 +02:00
Rik van Riel de1c9ce6f0 sched/numa: Skip some page migrations after a shared fault
Shared faults can lead to lots of unnecessary page migrations,
slowing down the system, and causing private faults to hit the
per-pgdat migration ratelimit.

This patch adds sysctl numa_balancing_migrate_deferred, which specifies
how many shared page migrations to skip unconditionally, after each page
migration that is skipped because it is a shared fault.

This reduces the number of page migrations back and forth in
shared fault situations. It also gives a strong preference to
the tasks that are already running where most of the memory is,
and to moving the other tasks to near the memory.

Testing this with a much higher scan rate than the default
still seems to result in fewer page migrations than before.

Memory seems to be somewhat better consolidated than previously,
with multi-instance specjbb runs on a 4 node system.

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-62-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 14:48:21 +02:00
Rik van Riel 1e3646ffc6 mm: numa: Revert temporarily disabling of NUMA migration
With the scan rate code working (at least for multi-instance specjbb),
the large hammer that is "sched: Do not migrate memory immediately after
switching node" can be replaced with something smarter. Revert temporarily
migration disabling and all traces of numa_migrate_seq.

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-61-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 14:48:20 +02:00
Rik van Riel 04bb2f9475 sched/numa: Adjust scan rate in task_numa_placement
Adjust numa_scan_period in task_numa_placement, depending on how much
useful work the numa code can do. The more local faults there are in a
given scan window the longer the period (and hence the slower the scan rate)
during the next window. If there are excessive shared faults then the scan
period will decrease with the amount of scaling depending on whether the
ratio of shared/private faults. If the preferred node changes then the
scan rate is reset to recheck if the task is properly placed.

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-59-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 14:48:16 +02:00
Rik van Riel dabe1d9924 sched/numa: Be more careful about joining numa groups
Due to the way the pid is truncated, and tasks are moved between
CPUs by the scheduler, it is possible for the current task_numa_fault
to group together tasks that do not actually share memory together.

This patch adds a few easy sanity checks to task_numa_fault, joining
tasks together if they share the same tsk->mm, or if the fault was on
a page with an elevated mapcount, in a shared VMA.

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-57-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 14:48:12 +02:00
Mel Gorman 0f19c17929 mm: numa: Do not batch handle PMD pages
With the THP migration races closed it is still possible to occasionally
see corruption. The problem is related to handling PMD pages in batch.
When a page fault is handled it can be assumed that the page being
faulted will also be flushed from the TLB. The same flushing does not
happen when handling PMD pages in batch. Fixing is straight forward but
there are a number of reasons not to

1. Multiple TLB flushes may have to be sent depending on what pages get
   migrated
2. The handling of PMDs in batch means that faults get accounted to
   the task that is handling the fault. While care is taken to only
   mark PMDs where the last CPU and PID match it can still have problems
   due to PID truncation when matching PIDs.
3. Batching on the PMD level may reduce faults but setting pmd_numa
   requires taking a heavy lock that can contend with THP migration
   and handling the fault requires the release/acquisition of the PTL
   for every page migrated. It's still pretty heavy.

PMD batch handling is not something that people ever have been happy
with. This patch removes it and later patches will deal with the
additional fault overhead using more installigent migrate rate adaption.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-48-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 14:47:55 +02:00
Peter Zijlstra 6688cc0547 mm: numa: Do not group on RO pages
And here's a little something to make sure not the whole world ends up
in a single group.

As while we don't migrate shared executable pages, we do scan/fault on
them. And since everybody links to libc, everybody ends up in the same
group.

Suggested-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1381141781-10992-47-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 14:47:53 +02:00
Rik van Riel 7851a45cd3 mm: numa: Copy cpupid on page migration
After page migration, the new page has the nidpid unset. This makes
every fault on a recently migrated page look like a first numa fault,
leading to another page migration.

Copying over the nidpid at page migration time should prevent erroneous
migrations of recently migrated pages.

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-46-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 14:47:51 +02:00
Peter Zijlstra 8c8a743c50 sched/numa: Use {cpu, pid} to create task groups for shared faults
While parallel applications tend to align their data on the cache
boundary, they tend not to align on the page or THP boundary.
Consequently tasks that partition their data can still "false-share"
pages presenting a problem for optimal NUMA placement.

This patch uses NUMA hinting faults to chain tasks together into
numa_groups. As well as storing the NID a task was running on when
accessing a page a truncated representation of the faulting PID is
stored. If subsequent faults are from different PIDs it is reasonable
to assume that those two tasks share a page and are candidates for
being grouped together. Note that this patch makes no scheduling
decisions based on the grouping information.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1381141781-10992-44-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 14:47:47 +02:00
Peter Zijlstra 90572890d2 mm: numa: Change page last {nid,pid} into {cpu,pid}
Change the per page last fault tracking to use cpu,pid instead of
nid,pid. This will allow us to try and lookup the alternate task more
easily. Note that even though it is the cpu that is store in the page
flags that the mpol_misplaced decision is still based on the node.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1381141781-10992-43-git-send-email-mgorman@suse.de
[ Fixed build failure on 32-bit systems. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 14:47:45 +02:00
Mel Gorman 25cbbef192 mm: numa: Trap pmd hinting faults only if we would otherwise trap PTE faults
Base page PMD faulting is meant to batch handle NUMA hinting faults from
PTEs. However, even is no PTE faults would ever be handled within a
range the kernel still traps PMD hinting faults. This patch avoids the
overhead.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-37-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 12:40:44 +02:00
Mel Gorman fc3147245d mm: numa: Limit NUMA scanning to migrate-on-fault VMAs
There is a 90% regression observed with a large Oracle performance test
on a 4 node system. Profiles indicated that the overhead was due to
contention on sp_lock when looking up shared memory policies. These
policies do not have the appropriate flags to allow them to be
automatically balanced so trapping faults on them is pointless. This
patch skips VMAs that do not have MPOL_F_MOF set.

[riel@redhat.com: Initial patch]

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reported-and-tested-by: Joe Mario <jmario@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-32-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 12:40:38 +02:00
Rik van Riel 6fe6b2d6da sched/numa: Do not migrate memory immediately after switching node
The load balancer can move tasks between nodes and does not take NUMA
locality into account. With automatic NUMA balancing this may result in the
tasks working set being migrated to the new node. However, as the fault
buffer will still store faults from the old node the schduler may decide to
reset the preferred node and migrate the task back resulting in more
migrations.

The ideal would be that the scheduler did not migrate tasks with a heavy
memory footprint but this may result nodes being overloaded. We could
also discard the fault information on task migration but this would still
cause all the tasks working set to be migrated. This patch simply avoids
migrating the memory for a short time after a task is migrated.

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-31-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 12:40:36 +02:00
Mel Gorman b795854b1f sched/numa: Set preferred NUMA node based on number of private faults
Ideally it would be possible to distinguish between NUMA hinting faults that
are private to a task and those that are shared. If treated identically
there is a risk that shared pages bounce between nodes depending on
the order they are referenced by tasks. Ultimately what is desirable is
that task private pages remain local to the task while shared pages are
interleaved between sharing tasks running on different nodes to give good
average performance. This is further complicated by THP as even
applications that partition their data may not be partitioning on a huge
page boundary.

To start with, this patch assumes that multi-threaded or multi-process
applications partition their data and that in general the private accesses
are more important for cpu->memory locality in the general case. Also,
no new infrastructure is required to treat private pages properly but
interleaving for shared pages requires additional infrastructure.

To detect private accesses the pid of the last accessing task is required
but the storage requirements are a high. This patch borrows heavily from
Ingo Molnar's patch "numa, mm, sched: Implement last-CPU+PID hash tracking"
to encode some bits from the last accessing task in the page flags as
well as the node information. Collisions will occur but it is better than
just depending on the node information. Node information is then used to
determine if a page needs to migrate. The PID information is used to detect
private/shared accesses. The preferred NUMA node is selected based on where
the maximum number of approximately private faults were measured. Shared
faults are not taken into consideration for a few reasons.

First, if there are many tasks sharing the page then they'll all move
towards the same node. The node will be compute overloaded and then
scheduled away later only to bounce back again. Alternatively the shared
tasks would just bounce around nodes because the fault information is
effectively noise. Either way accounting for shared faults the same as
private faults can result in lower performance overall.

The second reason is based on a hypothetical workload that has a small
number of very important, heavily accessed private pages but a large shared
array. The shared array would dominate the number of faults and be selected
as a preferred node even though it's the wrong decision.

The third reason is that multiple threads in a process will race each
other to fault the shared page making the fault information unreliable.

Signed-off-by: Mel Gorman <mgorman@suse.de>
[ Fix complication error when !NUMA_BALANCING. ]
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-30-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 12:40:35 +02:00
Mel Gorman 1bc115d87d mm: numa: Scan pages with elevated page_mapcount
Currently automatic NUMA balancing is unable to distinguish between false
shared versus private pages except by ignoring pages with an elevated
page_mapcount entirely. This avoids shared pages bouncing between the
nodes whose task is using them but that is ignored quite a lot of data.

This patch kicks away the training wheels in preparation for adding support
for identifying shared/private pages is now in place. The ordering is so
that the impact of the shared/private detection can be easily measured. Note
that the patch does not migrate shared, file-backed within vmas marked
VM_EXEC as these are generally shared library pages. Migrating such pages
is not beneficial as there is an expectation they are read-shared between
caches and iTLB and iCache pressure is generally low.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-28-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 12:40:32 +02:00
Mel Gorman ac8e895bd2 sched/numa: Add infrastructure for split shared/private accounting of NUMA hinting faults
Ideally it would be possible to distinguish between NUMA hinting faults
that are private to a task and those that are shared.  This patch prepares
infrastructure for separately accounting shared and private faults by
allocating the necessary buffers and passing in relevant information. For
now, all faults are treated as private and detection will be introduced
later.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-26-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 12:40:30 +02:00
Mel Gorman a1a46184e3 mm: numa: Do not migrate or account for hinting faults on the zero page
The zero page is not replicated between nodes and is often shared between
processes. The data is read-only and likely to be cached in local CPUs
if heavily accessed meaning that the remote memory access cost is less
of a concern. This patch prevents trapping faults on the zero pages. For
tasks using the zero page this will reduce the number of PTE updates,
TLB flushes and hinting faults.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
[ Correct use of is_huge_zero_page]
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-13-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 12:39:50 +02:00
Mel Gorman f123d74abf mm: Only flush TLBs if a transhuge PMD is modified for NUMA pte scanning
NUMA PTE scanning is expensive both in terms of the scanning itself and
the TLB flush if there are any updates. The TLB flush is avoided if no
PTEs are updated but there is a bug where transhuge PMDs are considered
to be updated even if they were already pmd_numa. This patch addresses
the problem and TLB flushes should be reduced.

Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-12-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 12:39:49 +02:00
Mel Gorman e920e14ca2 mm: Do not flush TLB during protection change if !pte_present && !migration_entry
NUMA PTE scanning is expensive both in terms of the scanning itself and
the TLB flush if there are any updates. Currently non-present PTEs are
accounted for as an update and incurring a TLB flush where it is only
necessary for anonymous migration entries. This patch addresses the
problem and should reduce TLB flushes.

Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-11-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 12:39:48 +02:00
Mel Gorman afcae2655b mm: Account for a THP NUMA hinting update as one PTE update
A THP PMD update is accounted for as 512 pages updated in vmstat.  This is
large difference when estimating the cost of automatic NUMA balancing and
can be misleading when comparing results that had collapsed versus split
THP. This patch addresses the accounting issue.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-10-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 12:39:46 +02:00
Mel Gorman a54a407fbf mm: Close races between THP migration and PMD numa clearing
THP migration uses the page lock to guard against parallel allocations
but there are cases like this still open

  Task A					Task B
  ---------------------				---------------------
  do_huge_pmd_numa_page				do_huge_pmd_numa_page
  lock_page
  mpol_misplaced == -1
  unlock_page
  goto clear_pmdnuma
						lock_page
						mpol_misplaced == 2
						migrate_misplaced_transhuge
  pmd = pmd_mknonnuma
  set_pmd_at

During hours of testing, one crashed with weird errors and while I have
no direct evidence, I suspect something like the race above happened.
This patch extends the page lock to being held until the pmd_numa is
cleared to prevent migration starting in parallel while the pmd_numa is
being cleared. It also flushes the old pmd entry and orders pagetable
insertion before rmap insertion.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-9-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 12:39:45 +02:00
Mel Gorman 8191acbd30 mm: numa: Sanitize task_numa_fault() callsites
There are three callers of task_numa_fault():

 - do_huge_pmd_numa_page():
     Accounts against the current node, not the node where the
     page resides, unless we migrated, in which case it accounts
     against the node we migrated to.

 - do_numa_page():
     Accounts against the current node, not the node where the
     page resides, unless we migrated, in which case it accounts
     against the node we migrated to.

 - do_pmd_numa_page():
     Accounts not at all when the page isn't migrated, otherwise
     accounts against the node we migrated towards.

This seems wrong to me; all three sites should have the same
sementaics, furthermore we should accounts against where the page
really is, we already know where the task is.

So modify all three sites to always account; we did after all receive
the fault; and always account to where the page is after migration,
regardless of success.

They all still differ on when they clear the PTE/PMD; ideally that
would get sorted too.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-8-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 12:39:44 +02:00
Mel Gorman b8916634b7 mm: Prevent parallel splits during THP migration
THP migrations are serialised by the page lock but on its own that does
not prevent THP splits. If the page is split during THP migration then
the pmd_same checks will prevent page table corruption but the unlock page
and other fix-ups potentially will cause corruption. This patch takes the
anon_vma lock to prevent parallel splits during migration.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-7-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 12:39:43 +02:00
Mel Gorman ff9042b11a mm: Wait for THP migrations to complete during NUMA hinting faults
The locking for migrating THP is unusual. While normal page migration
prevents parallel accesses using a migration PTE, THP migration relies on
a combination of the page_table_lock, the page lock and the existance of
the NUMA hinting PTE to guarantee safety but there is a bug in the scheme.

If a THP page is currently being migrated and another thread traps a
fault on the same page it checks if the page is misplaced. If it is not,
then pmd_numa is cleared. The problem is that it checks if the page is
misplaced without holding the page lock meaning that the racing thread
can be migrating the THP when the second thread clears the NUMA bit
and faults a stale page.

This patch checks if the page is potentially being migrated and stalls
using the lock_page if it is potentially being migrated before checking
if the page is misplaced or not.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-6-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 12:39:41 +02:00
Mel Gorman 0c3a775e1e mm: numa: Do not account for a hinting fault if we raced
If another task handled a hinting fault in parallel then do not double
account for it.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-5-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 12:39:40 +02:00
Peter Zijlstra c69307d533 sched/numa: Fix comments
Fix a 80 column violation and a PTE vs PMD reference.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1381141781-10992-4-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-09 12:39:30 +02:00
Linus Torvalds c15f5bbc94 Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
Pull powerpc fixes from Ben Herrenschmidt:
 "Here are a few powerpc fixes, all aimed at -stable, found in part
  thanks to the ramping up of a major distro testing and in part thanks
  to the LE guys hitting all sort interesting corner cases.

  The most scary are probably the register clobber issues in
  csum_partial_copy_generic(), especially since Anton even had a test
  case for that thing, which didn't manage to hit the bugs :-)

  Another highlight is that memory hotplug should work again with these
  fixes.

  Oh and the vio modalias one is worse than the cset implies as it
  upsets distro installers, so I've been told at least, which is why I'm
  shooting it to stable"

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc/tm: Switch out userspace PPR and DSCR sooner
  powerpc/tm: Turn interrupts hard off in tm_reclaim()
  powerpc/perf: Fix handling of FAB events
  powerpc/vio: Fix modalias_show return values
  powerpc/iommu: Use GFP_KERNEL instead of GFP_ATOMIC in iommu_init_table()
  powerpc/sysfs: Disable writing to PURR in guest mode
  powerpc: Restore registers on error exit from csum_partial_copy_generic()
  powerpc: Fix parameter clobber in csum_partial_copy_generic()
  powerpc: Fix memory hotplug with sparse vmemmap
2013-10-03 08:54:39 -07:00
Nathan Fontenot f7e3334a6b powerpc: Fix memory hotplug with sparse vmemmap
Previous commit 46723bfa540... introduced a new config option
HAVE_BOOTMEM_INFO_NODE that ended up breaking memory hot-remove for ppc
when sparse vmemmap is not defined.

This patch defines HAVE_BOOTMEM_INFO_NODE for ppc and adds the call to
register_page_bootmem_info_node. Without this we get a BUG_ON for memory
hot remove in put_page_bootmem().

This also adds a stub for register_page_bootmem_memmap to allow ppc to build
with sparse vmemmap defined. Leaving this as a stub is fine since the same
vmemmap addresses are also handled in vmemmap_populate and as such are
properly mapped.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: <stable@vger.kernel.org> [v3.9+]
2013-10-03 17:21:38 +10:00
Wanpeng Li fb31ba30fb mm/hwpoison: fix the lack of one reference count against poisoned page
The lack of one reference count against poisoned page for hwpoison_inject
w/o hwpoison_filter enabled result in hwpoison detect -1 users still
referenced the page, however, the number should be 0 except the poison
handler held one after successfully unmap.  This patch fix it by hold one
referenced count against poisoned page for hwpoison_inject w/ and w/o
hwpoison_filter enabled.

Before patch:

[   71.902112] Injecting memory failure at pfn 224706
[   71.902137] MCE 0x224706: dirty LRU page recovery: Failed
[   71.902138] MCE 0x224706: dirty LRU page still referenced by -1 users

After patch:

[   94.710860] Injecting memory failure at pfn 215b68
[   94.710885] MCE 0x215b68: dirty LRU page recovery: Recovered

Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-30 14:31:03 -07:00
Wanpeng Li 2d421acd15 mm/hwpoison: fix false report on 2nd attempt at page recovery
If the page is poisoned by software injection w/ MF_COUNT_INCREASED
flag, there is a false report during the 2nd attempt at page recovery
which is not truthful.

This patch fixes it by reporting the first attempt to try free buddy
page recovery if MF_COUNT_INCREASED is set.

Before patch:

[  346.332041] Injecting memory failure at pfn 200010
[  346.332189] MCE 0x200010: free buddy, 2nd try page recovery: Delayed

After patch:

[  297.742600] Injecting memory failure at pfn 200010
[  297.742941] MCE 0x200010: free buddy page recovery: Delayed

Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-30 14:31:02 -07:00
Wanpeng Li e76d30e20b mm/hwpoison: fix test for a transparent huge page
PageTransHuge() can't guarantee the page is a transparent huge page
since it returns true for both transparent huge and hugetlbfs pages.

This patch fixes it by checking the page is also !hugetlbfs page.

Before patch:

[  121.571128] Injecting memory failure at pfn 23a200
[  121.571141] MCE 0x23a200: huge page recovery: Delayed
[  140.355100] MCE: Memory failure is now running on 0x23a200

After patch:

[   94.290793] Injecting memory failure at pfn 23a000
[   94.290800] MCE 0x23a000: huge page recovery: Delayed
[  105.722303] MCE: Software-unpoisoned page 0x23a000

Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-30 14:31:02 -07:00
Wanpeng Li 20cb6cab52 mm/hwpoison: fix traversal of hugetlbfs pages to avoid printk flood
madvise_hwpoison won't check if the page is small page or huge page and
traverses in small page granularity against the range unconditionally,
which result in a printk flood "MCE xxx: already hardware poisoned" if
the page is a huge page.

This patch fixes it by using compound_order(compound_head(page)) for
huge page iterator.

Testcase:

#define _GNU_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <sys/mman.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <errno.h>

#define PAGES_TO_TEST 3
#define PAGE_SIZE	4096 * 512

int main(void)
{
	char *mem;
	int i;

	mem = mmap(NULL, PAGES_TO_TEST * PAGE_SIZE,
			PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, 0, 0);

	if (madvise(mem, PAGES_TO_TEST * PAGE_SIZE, MADV_HWPOISON) == -1)
		return -1;

	munmap(mem, PAGES_TO_TEST * PAGE_SIZE);

	return 0;
}

Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-30 14:31:02 -07:00
Vlastimil Babka eadb41ae82 mm/mlock.c: prevent walking off the end of a pagetable in no-pmd configuration
The function __munlock_pagevec_fill() introduced in commit 7a8010cd36
("mm: munlock: manual pte walk in fast path instead of
follow_page_mask()") uses pmd_addr_end() for restricting its operation
within current page table.

This is insufficient on architectures/configurations where pmd is folded
and pmd_addr_end() just returns the end of the full range to be walked.
In this case, it allows pte++ to walk off the end of a page table
resulting in unpredictable behaviour.

This patch fixes the function by using pgd_addr_end() and pud_addr_end()
before pmd_addr_end(), which will yield correct page table boundary on
all configurations.  This is similar to what existing page walkers do
when walking each level of the page table.

Additionaly, the patch clarifies a comment for get_locked_pte() call in the
function.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Cc: Jörn Engel <joern@logfs.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michel Lespinasse <walken@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-30 14:31:02 -07:00
Rafael Aquini 117aad1e9e mm: avoid reinserting isolated balloon pages into LRU lists
Isolated balloon pages can wrongly end up in LRU lists when
migrate_pages() finishes its round without draining all the isolated
page list.

The same issue can happen when reclaim_clean_pages_from_list() tries to
reclaim pages from an isolated page list, before migration, in the CMA
path.  Such balloon page leak opens a race window against LRU lists
shrinkers that leads us to the following kernel panic:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000028
  IP: [<ffffffff810c2625>] shrink_page_list+0x24e/0x897
  PGD 3cda2067 PUD 3d713067 PMD 0
  Oops: 0000 [#1] SMP
  CPU: 0 PID: 340 Comm: kswapd0 Not tainted 3.12.0-rc1-22626-g4367597 #87
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  RIP: shrink_page_list+0x24e/0x897
  RSP: 0000:ffff88003da499b8  EFLAGS: 00010286
  RAX: 0000000000000000 RBX: ffff88003e82bd60 RCX: 00000000000657d5
  RDX: 0000000000000000 RSI: 000000000000031f RDI: ffff88003e82bd40
  RBP: ffff88003da49ab0 R08: 0000000000000001 R09: 0000000081121a45
  R10: ffffffff81121a45 R11: ffff88003c4a9a28 R12: ffff88003e82bd40
  R13: ffff88003da0e800 R14: 0000000000000001 R15: ffff88003da49d58
  FS:  0000000000000000(0000) GS:ffff88003fc00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00000000067d9000 CR3: 000000003ace5000 CR4: 00000000000407b0
  Call Trace:
    shrink_inactive_list+0x240/0x3de
    shrink_lruvec+0x3e0/0x566
    __shrink_zone+0x94/0x178
    shrink_zone+0x3a/0x82
    balance_pgdat+0x32a/0x4c2
    kswapd+0x2f0/0x372
    kthread+0xa2/0xaa
    ret_from_fork+0x7c/0xb0
  Code: 80 7d 8f 01 48 83 95 68 ff ff ff 00 4c 89 e7 e8 5a 7b 00 00 48 85 c0 49 89 c5 75 08 80 7d 8f 00 74 3e eb 31 48 8b 80 18 01 00 00 <48> 8b 74 0d 48 8b 78 30 be 02 00 00 00 ff d2 eb
  RIP  [<ffffffff810c2625>] shrink_page_list+0x24e/0x897
   RSP <ffff88003da499b8>
  CR2: 0000000000000028
  ---[ end trace 703d2451af6ffbfd ]---
  Kernel panic - not syncing: Fatal exception

This patch fixes the issue, by assuring the proper tests are made at
putback_movable_pages() & reclaim_clean_pages_from_list() to avoid
isolated balloon pages being wrongly reinserted in LRU lists.

[akpm@linux-foundation.org: clarify awkward comment text]
Signed-off-by: Rafael Aquini <aquini@redhat.com>
Reported-by: Luiz Capitulino <lcapitulino@redhat.com>
Tested-by: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-30 14:31:02 -07:00
Darrick J. Wong 83b2944fd2 mm/bounce.c: fix a regression where MS_SNAP_STABLE (stable pages snapshotting) was ignored
The "force" parameter in __blk_queue_bounce was being ignored, which
means that stable page snapshots are not always happening (on ext3).
This of course leads to DIF disks reporting checksum errors, so fix this
regression.

The regression was introduced in commit 6bc454d150 ("bounce: Refactor
__blk_queue_bounce to not use bi_io_vec")

Reported-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: <stable@vger.kernel.org>	[3.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-30 14:31:02 -07:00
David Rientjes f6ea3adb70 mm/compaction.c: periodically schedule when freeing pages
We've been getting warnings about an excessive amount of time spent
allocating pages for migration during memory compaction without
scheduling.  isolate_freepages_block() already periodically checks for
contended locks or the need to schedule, but isolate_freepages() never
does.

When a zone is massively long and no suitable targets can be found, this
iteration can be quite expensive without ever doing cond_resched().

Check periodically for the need to reschedule while the compaction free
scanner iterates.

Signed-off-by: David Rientjes <rientjes@google.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.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>
2013-09-30 14:31:01 -07:00
Joonyoung Shim 7393dc45f6 revert "mm/memory-hotplug: fix lowmem count overflow when offline pages"
This reverts commit cea27eb2a2 ("mm/memory-hotplug: fix lowmem count
overflow when offline pages").

The fixed bug by commit cea27eb was fixed to another way by commit
3dcc0571cd ("mm: correctly update zone->managed_pages").  That commit
enhances memory_hotplug.c to adjust totalhigh_pages when hot-removing
memory, for details please refer to:

  http://marc.info/?l=linux-mm&m=136957578620221&w=2

As a result, commit cea27eb2a2 currently causes duplicated decreasing
of totalhigh_pages, thus the revert.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Jiang Liu <liuj97@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-30 14:31:01 -07:00
Christoph Lameter 3e374919b3 slab_common: Do not check for duplicate slab names
SLUB can alias multiple slab kmem_create_requests to one slab cache to save
memory and increase the cache hotness. As a result the name of the slab can be
stale. Only check the name for duplicates if we are in debug mode where we do
not merge multiple caches.

This fixes the following problem reported by Jonathan Brassow:

  The problem with kmem_cache* is this:

  *) Assume CONFIG_SLUB is set
  1) kmem_cache_create(name="foo-a")
  - creates new kmem_cache structure
  2) kmem_cache_create(name="foo-b")
  - If identical cache characteristics, it will be merged with the previously
    created cache associated with "foo-a".  The cache's refcount will be
    incremented and an alias will be created via sysfs_slab_alias().
  3) kmem_cache_destroy(<ptr>)
  - Attempting to destroy cache associated with "foo-a", but instead the
    refcount is simply decremented.  I don't even think the sysfs aliases are
    ever removed...
  4) kmem_cache_create(name="foo-a")
  - This FAILS because kmem_cache_sanity_check colides with the existing
    name ("foo-a") associated with the non-removed cache.

  This is a problem for RAID (specifically dm-raid) because the name used
  for the kmem_cache_create is ("raid%d-%p", level, mddev).  If the cache
  persists for long enough, the memory address of an old mddev will be
  reused for a new mddev - causing an identical formulation of the cache
  name.  Even though kmem_cache_destory had long ago been used to delete
  the old cache, the merging of caches has cause the name and cache of that
  old instance to be preserved and causes a colision (and thus failure) in
  kmem_cache_create().  I see this regularly in my testing.

Reported-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2013-09-28 09:47:41 +03:00
Paul E. McKenney 22356f447c mm: Place preemption point in do_mlockall() loop
There is a loop in do_mlockall() that lacks a preemption point, which
means that the following can happen on non-preemptible builds of the
kernel. Dave Jones reports:

 "My fuzz tester keeps hitting this.  Every instance shows the non-irq
  stack came in from mlockall.  I'm only seeing this on one box, but
  that has more ram (8gb) than my other machines, which might explain
  it.

    INFO: rcu_preempt self-detected stall on CPU { 3}  (t=6500 jiffies g=470344 c=470343 q=0)
    sending NMI to all CPUs:
    NMI backtrace for cpu 3
    CPU: 3 PID: 29664 Comm: trinity-child2 Not tainted 3.11.0-rc1+ #32
    Call Trace:
      lru_add_drain_all+0x15/0x20
      SyS_mlockall+0xa5/0x1a0
      tracesys+0xdd/0xe2"

This commit addresses this problem by inserting the required preemption
point.

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 19:44:40 -07:00