Pull slab changes from Pekka Enberg:
"The biggest change is byte-sized freelist indices which reduces slab
freelist memory usage:
https://lkml.org/lkml/2013/12/2/64"
* 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux:
mm: slab/slub: use page->list consistently instead of page->lru
mm/slab.c: cleanup outdated comments and unify variables naming
slab: fix wrongly used macro
slub: fix high order page allocation problem with __GFP_NOFAIL
slab: Make allocations with GFP_ZERO slightly more efficient
slab: make more slab management structure off the slab
slab: introduce byte sized index for the freelist of a slab
slab: restrict the number of objects in a slab
slab: introduce helper functions to get/set free object
slab: factor out calculate nr objects in cache_estimate
Memcg-awareness turned kmem_cache_create() into a dirty interweaving of
memcg-only and except-for-memcg calls. To clean this up, let's move the
code responsible for memcg cache creation to a separate function.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Glauber Costa <glommer@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
commit 'slab: restrict the number of objects in a slab' uses
__builtin_constant_p() on #if macro. It is wrong usage of builtin
function, but it is compiled on x86 without any problem, so I can't
find it before 0 day build system find it.
This commit fixes the situation by using KMALLOC_MIN_SIZE, instead of
KMALLOC_SHIFT_LOW. KMALLOC_SHIFT_LOW is parsed to ilog2() on some
architecture and this ilog2() uses __builtin_constant_p() and results in
the problem. This problem would disappear by using KMALLOC_MIN_SIZE,
since it is just constant.
Tested-by: David Rientjes <rientjes@google.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
GFP_THISNODE is for callers that implement their own clever fallback to
remote nodes. It restricts the allocation to the specified node and
does not invoke reclaim, assuming that the caller will take care of it
when the fallback fails, e.g. through a subsequent allocation request
without GFP_THISNODE set.
However, many current GFP_THISNODE users only want the node exclusive
aspect of the flag, without actually implementing their own fallback or
triggering reclaim if necessary. This results in things like page
migration failing prematurely even when there is easily reclaimable
memory available, unless kswapd happens to be running already or a
concurrent allocation attempt triggers the necessary reclaim.
Convert all callsites that don't implement their own fallback strategy
to __GFP_THISNODE. This restricts the allocation a single node too, but
at the same time allows the allocator to enter the slowpath, wake
kswapd, and invoke direct reclaim if necessary, to make the allocation
happen when memory is full.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Jan Stancek <jstancek@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To prepare to implement byte sized index for managing the freelist
of a slab, we should restrict the number of objects in a slab to be less
or equal to 256, since byte only represent 256 different values.
Setting the size of object to value equal or more than newly introduced
SLAB_OBJ_MIN_SIZE ensures that the number of objects in a slab is less or
equal to 256 for a slab with 1 page.
If page size is rather larger than 4096, above assumption would be wrong.
In this case, we would fall back on 2 bytes sized index.
If minimum size of kmalloc is less than 16, we use it as minimum object
size and give up this optimization.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Pull SLAB changes from Pekka Enberg:
"Random bug fixes that have accumulated in my inbox over the past few
months"
* 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux:
mm: Fix warning on make htmldocs caused by slab.c
mm: slub: work around unneeded lockdep warning
mm: sl[uo]b: fix misleading comments
slub: Fix possible format string bug.
slub: use lockdep_assert_held
slub: Fix calculation of cpu slabs
slab.h: remove duplicate kmalloc declaration and fix kernel-doc warnings
On x86, SLUB creates and handles <=8192-byte allocations internally.
It passes larger ones up to the allocator. Saying "up to order 2" is,
at best, ambiguous. Is that order-1? Or (order-2 bytes)? Make
it more clear.
SLOB commits a similar sin. It *handles* page-size requests, but the
comment says that it passes up "all page size and larger requests".
SLOB also swaps around the order of the very-similarly-named
KMALLOC_SHIFT_HIGH and KMALLOC_SHIFT_MAX #defines. Make it
consistent with the order of the other two allocators.
Cc: Matt Mackall <mpm@selenic.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
We relocate root cache's memcg_params whenever we need to grow the
memcg_caches array to accommodate all kmem-active memory cgroups.
Currently on relocation we free the old version immediately, which can
lead to use-after-free, because the memcg_caches array is accessed
lock-free (see cache_from_memcg_idx()). This patch fixes this by making
memcg_params RCU-protected for root caches.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix kernel-doc warning for duplicate definition of 'kmalloc':
Documentation/DocBook/kernel-api.xml:9483: element refentry: validity error : ID API-kmalloc already defined
<refentry id="API-kmalloc">
Also combine the kernel-doc info from the 2 kmalloc definitions into one
block and remove the "see kcalloc" comment since kmalloc now contains the
@flags info.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Fix kernel-doc warning for duplicate definition of 'kmalloc':
Documentation/DocBook/kernel-api.xml:9483: element refentry: validity error : ID API-kmalloc already defined
<refentry id="API-kmalloc">
Also combine the kernel-doc info from the 2 kmalloc definitions into one
block and remove the "see kcalloc" comment since kmalloc now contains the
@flags info.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull SLAB changes from Pekka Enberg:
"The patches from Joonsoo Kim switch mm/slab.c to use 'struct page' for
slab internals similar to mm/slub.c. This reduces memory usage and
improves performance:
https://lkml.org/lkml/2013/10/16/155
Rest of the changes are bug fixes from various people"
* 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux: (21 commits)
mm, slub: fix the typo in mm/slub.c
mm, slub: fix the typo in include/linux/slub_def.h
slub: Handle NULL parameter in kmem_cache_flags
slab: replace non-existing 'struct freelist *' with 'void *'
slab: fix to calm down kmemleak warning
slub: proper kmemleak tracking if CONFIG_SLUB_DEBUG disabled
slab: rename slab_bufctl to slab_freelist
slab: remove useless statement for checking pfmemalloc
slab: use struct page for slab management
slab: replace free and inuse in struct slab with newly introduced active
slab: remove SLAB_LIMIT
slab: remove kmem_bufctl_t
slab: change the management method of free objects of the slab
slab: use __GFP_COMP flag for allocating slab pages
slab: use well-defined macro, virt_to_slab()
slab: overloading the RCU head over the LRU for RCU free
slab: remove cachep in struct slab_rcu
slab: remove nodeid in struct slab
slab: remove colouroff in struct slab
slab: change return type of kmem_getpages() to struct page
...
With build-time size checking, we can overload the RCU head over the LRU
of struct page to free pages of a slab in rcu context. This really help to
implement to overload the struct slab over the struct page and this
eventually reduce memory usage and cache footprint of the SLAB.
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
The kmalloc* functions of all slab allcoators are similar now so
lets move them into slab.h. This requires some function naming changes
in slob.
As a results of this patch there is a common set of functions for
all allocators. Also means that kmalloc_large() is now available
in general to perform large order allocations that go directly
via the page allocator. kmalloc_large() can be substituted if
kmalloc() throws warnings because of too large allocations.
kmalloc_large() has exactly the same semantics as kmalloc but
can only used for allocations > PAGE_SIZE.
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
At the moment, kmalloc() isn't even listed in the kernel API
documentation (DocBook/kernel-api.html after running "make htmldocs").
Another issue is that the documentation for kmalloc_node()
refers to kcalloc()'s documentation to describe its 'flags' parameter,
while kcalloc() refered to kmalloc()'s documentation, which doesn't exist!
This patch is a proposed fix for this. It also removes the documentation
for kmalloc() in include/linux/slob_def.h which isn't included to
generate the documentation anyway. This way, kmalloc() is described
in only one place.
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Make the SLOB specific stuff harmonize more with the way the other allocators
do it. Create the typical kmalloc constants for that purpose. SLOB does not
support it but the constants help us avoid #ifdefs.
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Have a common definition fo the kmalloc cache arrays in
SLAB and SLUB
Acked-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Standardize the constants that describe the smallest and largest
object kept in the kmalloc arrays for SLAB and SLUB.
Differentiate between the maximum size for which a slab cache is used
(KMALLOC_MAX_CACHE_SIZE) and the maximum allocatable size
(KMALLOC_MAX_SIZE, KMALLOC_MAX_ORDER).
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Extract the function to determine the index of the slab within
the array of kmalloc caches as well as a function to determine
maximum object size from the nr of the kmalloc slab.
This is used here only to simplify slub bootstrap but will
be used later also for SLAB.
Acked-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Move these functions higher up in slab.h so that they are grouped with other
generic kmalloc related definitions.
Acked-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
SLAB allows us to tune a particular cache behavior with tunables. When
creating a new memcg cache copy, we'd like to preserve any tunables the
parent cache already had.
This could be done by an explicit call to do_tune_cpucache() after the
cache is created. But this is not very convenient now that the caches are
created from common code, since this function is SLAB-specific.
Another method of doing that is taking advantage of the fact that
do_tune_cpucache() is always called from enable_cpucache(), which is
called at cache initialization. We can just preset the values, and then
things work as expected.
It can also happen that a root cache has its tunables updated during
normal system operation. In this case, we will propagate the change to
all caches that are already active.
This change will require us to move the assignment of root_cache in
memcg_params a bit earlier. We need this to be already set - which
memcg_kmem_register_cache will do - when we reach __kmem_cache_create()
Signed-off-by: Glauber Costa <glommer@parallels.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Frederic Weisbecker <fweisbec@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: JoonSoo Kim <js1304@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Rik van Riel <riel@redhat.com>
Cc: Suleiman Souhlal <suleiman@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When we create caches in memcgs, we need to display their usage
information somewhere. We'll adopt a scheme similar to /proc/meminfo,
with aggregate totals shown in the global file, and per-group information
stored in the group itself.
For the time being, only reads are allowed in the per-group cache.
Signed-off-by: Glauber Costa <glommer@parallels.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Frederic Weisbecker <fweisbec@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: JoonSoo Kim <js1304@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Rik van Riel <riel@redhat.com>
Cc: Suleiman Souhlal <suleiman@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Implement destruction of memcg caches. Right now, only caches where our
reference counter is the last remaining are deleted. If there are any
other reference counters around, we just leave the caches lying around
until they go away.
When that happens, a destruction function is called from the cache code.
Caches are only destroyed in process context, so we queue them up for
later processing in the general case.
Signed-off-by: Glauber Costa <glommer@parallels.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Frederic Weisbecker <fweisbec@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: JoonSoo Kim <js1304@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Rik van Riel <riel@redhat.com>
Cc: Suleiman Souhlal <suleiman@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allow a memcg parameter to be passed during cache creation. When the slub
allocator is being used, it will only merge caches that belong to the same
memcg. We'll do this by scanning the global list, and then translating
the cache to a memcg-specific cache
Default function is created as a wrapper, passing NULL to the memcg
version. We only merge caches that belong to the same memcg.
A helper is provided, memcg_css_id: because slub needs a unique cache name
for sysfs. Since this is visible, but not the canonical location for slab
data, the cache name is not used, the css_id should suffice.
Signed-off-by: Glauber Costa <glommer@parallels.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Frederic Weisbecker <fweisbec@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: JoonSoo Kim <js1304@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Rik van Riel <riel@redhat.com>
Cc: Suleiman Souhlal <suleiman@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For the kmem slab controller, we need to record some extra information in
the kmem_cache structure.
Signed-off-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Suleiman Souhlal <suleiman@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Frederic Weisbecker <fweisbec@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: JoonSoo Kim <js1304@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Rik van Riel <riel@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This function is identically defined in all three allocators
and it's trivial to move it to slab.h
Since now it's static, inline, header-defined function
this patch also drops the EXPORT_SYMBOL tag.
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Matt Mackall <mpm@selenic.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Currently slob falls back to regular kmalloc for this case.
With this patch kmalloc_track_caller() is correctly implemented,
thus tracing the specified caller.
This is important to trace accurately allocations performed by
krealloc, kstrdup, kmemdup, etc.
Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
All allocators have some sort of support for the bootstrap status.
Setup a common definition for the boot states and make all slab
allocators use that definition.
Reviewed-by: Glauber Costa <glommer@parallels.com>
Reviewed-by: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Kmem_cache_create() does a variety of sanity checks but those
vary depending on the allocator. Use the strictest tests and put them into
a slab_common file. Make the tests conditional on CONFIG_DEBUG_VM.
This patch has the effect of adding sanity checks for SLUB and SLOB
under CONFIG_DEBUG_VM and removes the checks in SLAB for !CONFIG_DEBUG_VM.
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Define a struct that describes common fields used in all slab allocators.
A slab allocator either uses the common definition (like SLOB) or is
required to provide members of kmem_cache with the definition given.
After that it will be possible to share code that
only operates on those fields of kmem_cache.
The patch basically takes the slob definition of kmem cache and
uses the field namees for the other allocators.
It also standardizes the names used for basic object lengths in
allocators:
object_size Struct size specified at kmem_cache_create. Basically
the payload expected to be used by the subsystem.
size The size of memory allocator for each object. This size
is larger than object_size and includes padding, alignment
and extra metadata for each object (f.e. for debugging
and rcu).
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
ULONG_MAX is often used to check for integer overflow when calculating
allocation size. While ULONG_MAX happens to work on most systems, there
is no guarantee that `size_t' must be the same size as `long'.
This patch introduces SIZE_MAX, the maximum value of `size_t', to improve
portability and readability for allocation size validation.
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Acked-by: Alex Elder <elder@dreamhost.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduce a kmalloc_array() wrapper that performs integer overflow
checking without zeroing the memory.
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Suggested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Provide description for alignment defines.
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Every slab has its on alignment definition in include/linux/sl?b_def.h. Extract those
and define a common set in include/linux/slab.h.
SLOB: As notes sometimes we need double word alignment on 32 bit. This gives all
structures allocated by SLOB a unsigned long long alignment like the others do.
SLAB: If ARCH_SLAB_MINALIGN is not set SLAB would set ARCH_SLAB_MINALIGN to
zero meaning no alignment at all. Give it the default unsigned long long alignment.
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
The last user was ext4 and Eric Sandeen removed the call in a recent patch. See
the following URL for the discussion:
http://marc.info/?l=linux-ext4&m=129546975702198&w=2
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
In slab, all __xxx_track_caller is defined on CONFIG_DEBUG_SLAB || CONFIG_TRACING,
thus caller tracking function should be worked for CONFIG_TRACING. But if
CONFIG_DEBUG_SLAB is not set, include/linux/slab.h will define xxx_track_caller to
__xxx() without consideration of CONFIG_TRACING. This will break the caller tracking
behaviour then.
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Dmitry Monakhov <dmonakhov@openvz.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
As suggested by Linus, introduce a kern_ptr_validate() helper that does some
sanity checks to make sure a pointer is a valid kernel pointer. This is a
preparational step for fixing SLUB kmem_ptr_validate().
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch allow to inject faults only for specific slabs.
In order to preserve default behavior cache filter is off by
default (all caches are faulty).
One may define specific set of slabs like this:
# mark skbuff_head_cache as faulty
echo 1 > /sys/kernel/slab/skbuff_head_cache/failslab
# Turn on cache filter (off by default)
echo 1 > /sys/kernel/debug/failslab/cache-filter
# Turn on fault injection
echo 1 > /sys/kernel/debug/failslab/times
echo 1 > /sys/kernel/debug/failslab/probability
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
With kmemcheck enabled, the slab allocator needs to do this:
1. Tell kmemcheck to allocate the shadow memory which stores the status of
each byte in the allocation proper, e.g. whether it is initialized or
uninitialized.
2. Tell kmemcheck which parts of memory that should be marked uninitialized.
There are actually a few more states, such as "not yet allocated" and
"recently freed".
If a slab cache is set up using the SLAB_NOTRACK flag, it will never return
memory that can take page faults because of kmemcheck.
If a slab cache is NOT set up using the SLAB_NOTRACK flag, callers can still
request memory with the __GFP_NOTRACK flag. This does not prevent the page
faults from occuring, however, but marks the object in question as being
initialized so that no warnings will ever be produced for this object.
In addition to (and in contrast to) __GFP_NOTRACK, the
__GFP_NOTRACK_FALSE_POSITIVE flag indicates that the allocation should
not be tracked _because_ it would produce a false positive. Their values
are identical, but need not be so in the future (for example, we could now
enable/disable false positives with a config option).
Parts of this patch were contributed by Pekka Enberg but merged for
atomicity.
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
[rebased for mainline inclusion]
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
As explained by Benjamin Herrenschmidt:
Oh and btw, your patch alone doesn't fix powerpc, because it's missing
a whole bunch of GFP_KERNEL's in the arch code... You would have to
grep the entire kernel for things that check slab_is_available() and
even then you'll be missing some.
For example, slab_is_available() didn't always exist, and so in the
early days on powerpc, we used a mem_init_done global that is set form
mem_init() (not perfect but works in practice). And we still have code
using that to do the test.
Therefore, mask out __GFP_WAIT, __GFP_IO, and __GFP_FS in the slab allocators
in early boot code to avoid enabling interrupts.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
This patch adds the callbacks to kmemleak_(alloc|free) functions from
the slab allocator. The patch also adds the SLAB_NOLEAKTRACE flag to
avoid recursive calls to kmemleak when it allocates its own data
structures.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
kzfree() is a wrapper for kfree() that additionally zeroes the underlying
memory before releasing it to the slab allocator.
Currently there is code which memset()s the memory region of an object
before releasing it back to the slab allocator to make sure
security-sensitive data are really zeroed out after use.
These callsites can then just use kzfree() which saves some code, makes
users greppable and allows for a stupid destructor that isn't necessarily
aware of the actual object size.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Matt Mackall <mpm@selenic.com>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This #endif in slab.h is described as closing the inner block while it's for
the big CONFIG_NUMA one. That makes reading the code a bit harder.
This trivial patch fixes the comment.
Signed-off-by: Pascal Terjan <pterjan@mandriva.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
This patch replaces __builtin_return_address(0) with _RET_IP_, since a
previous patch moved _RET_IP_ and _THIS_IP_ to include/linux/kernel.h and
they're widely available now. This makes for shorter and easier to read
code.
[penberg@cs.helsinki.fi: remove _RET_IP_ casts to void pointer]
Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Explain this SLAB_DESTROY_BY_RCU thing...
[hugh@veritas.com: add a pointer to comment in mm/slab.c]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Lose dummy ->write hook in case of SLUB, it's possible now.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Linus Torvalds