This patch optimizes slab_free() debug check to use "c->node != NUMA_NO_NODE"
instead of "c->node >= 0" because the former generates smaller code on x86-64:

  Before:

    4736:       48 39 70 08             cmp    %rsi,0x8(%rax)
    473a:       75 26                   jne    4762 <kfree+0xa2>
    473c:       44 8b 48 10             mov    0x10(%rax),%r9d
    4740:       45 85 c9                test   %r9d,%r9d
    4743:       78 1d                   js     4762 <kfree+0xa2>

  After:

    4736:       48 39 70 08             cmp    %rsi,0x8(%rax)
    473a:       75 23                   jne    475f <kfree+0x9f>
    473c:       83 78 10 ff             cmpl   $0xffffffffffffffff,0x10(%rax)
    4740:       74 1d                   je     475f <kfree+0x9f>

This patch also cleans up __slab_alloc() to use NUMA_NO_NODE instead of "-1"
for enabling debugging for a per-CPU cache.
Acked-by: NChristoph Lameter <cl@linux.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Make kmalloc_cache_alloc_node_notrace(), kmalloc_large_node()
and __kmalloc_node_track_caller() to be compiled only when
CONFIG_NUMA is selected.
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NNamhyung Kim <namhyung@gmail.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

The unfreeze_slab() releases page's PG_locked bit but was missing
proper annotation. The deactivate_slab() needs to be marked also
since it calls unfreeze_slab() without grabbing the lock.
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NNamhyung Kim <namhyung@gmail.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

The bit-ops routines require its arg to be a pointer to unsigned long.
This leads sparse to complain about different signedness as follows:

 mm/slub.c:2425:49: warning: incorrect type in argument 2 (different signedness)
 mm/slub.c:2425:49:    expected unsigned long volatile *addr
 mm/slub.c:2425:49:    got long *map
Acked-by: NChristoph Lameter <cl@linux.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NNamhyung Kim <namhyung@gmail.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

There are a couple of places where repeat the same statements when removing
a page from the partial list. Consolidate that into __remove_partial().
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Pass the actual values used for inactive and active redzoning to the
functions that check the objects. Avoids a lot of the ? : things to
lookup the values in the functions.
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Reduce the #ifdefs and simplify bootstrap by making SMP and NUMA as much alike
as possible. This means that there will be an additional indirection to get to
the kmem_cache_node field under SMP.
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

This reverts commit 5249d039500f05a5ab379286b1d23ab9b04d3f2c. It's not needed
after commit bbddff05 ("percpu: use percpu
allocator on UP too").

As explained by Linus "I'm Proud to be an American" Torvalds:

  Looking at the merging code, I actually think it's totally
  buggy. If you have something like this:

   - load module A: create slab cache A

   - load module B: create slab cache B that can merge with A

   - unload module A

   - "cat /proc/slabinfo": BOOM. Oops.

  exactly because the name is not handled correctly, and you'll have
  module B holding open a slab cache that has a name pointer that points
  to module A that no longer exists.

This patch fixes the problem by using kstrdup() to allocate dynamic memory for
->name of "struct kmem_cache" as suggested by Christoph Lameter.
Acked-by: NChristoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Reported-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Conflicts:

	mm/slub.c

Since the percpu allocator does not provide early allocation in UP mode (only
in SMP configurations) use __get_free_page() to improvise a compound page
allocation that can be later freed via kfree().

Compound pages will be released when the cpu caches are resized.
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Now that the kmalloc_caches array is dynamically allocated at boot,
SLUB_RESILIENCY_TEST needs to be fixed to pass the correct type.
Acked-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Memory hotplug allocates and frees per node structures. Use the correct name.
Acked-by: NDavid Rientjes <rientjes@google.com>
Acked-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

On Wed, 25 Aug 2010, Randy Dunlap wrote:
> mm/slub.c:1732: error: implicit declaration of function 'slab_pre_alloc_hook'
> mm/slub.c:1751: error: implicit declaration of function 'slab_post_alloc_hook'
> mm/slub.c:1881: error: implicit declaration of function 'slab_free_hook'
> mm/slub.c:1886: error: implicit declaration of function 'slab_free_hook_irq'

Empty functions are missing if the runtime debuggability option is compiled
out.

Provide the fall back functions to empty hooks if SLUB_DEBUG is not set.
Acked-by: NRandy Dunlap <randy.dunlap@oracle.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Move the gfpflags masking into the hooks for checkers and into the slowpaths.
gfpflag masking requires access to a global variable and thus adds an
additional cacheline reference to the hotpaths.

If no hooks are active then the gfpflag masking will result in
code that the compiler can toss out.
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Extract the code that memory checkers and other verification tools use from
the hotpaths. Makes it easier to add new ones and reduces the disturbances
of the hotpaths.
Signed-off-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

kmalloc caches are statically defined and may take up a lot of space just
because the sizes of the node array has to be dimensioned for the largest
node count supported.

This patch makes the size of the kmem_cache structure dynamic throughout by
creating a kmem_cache slab cache for the kmem_cache objects. The bootstrap
occurs by allocating the initial one or two kmem_cache objects from the
page allocator.

C2->C3
	- Fix various issues indicated by David
	- Make create kmalloc_cache return a kmem_cache * pointer.
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

The percpu allocator can now handle allocations during early boot.
So drop the static kmem_cache_cpu array.

Cc: Tejun Heo <tj@kernel.org>
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Remove the dynamic dma slab allocation since this causes too many issues with
nested locks etc etc. The change avoids passing gfpflags into many functions.

V3->V4:
- Create dma caches in kmem_cache_init() instead of kmem_cache_init_late().
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Compiler folds the debgging functions into the critical paths.
Avoid that by adding noinline to the functions that check for
problems.
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Serialize kmem_cache_create and kmem_cache_destroy using the slub_lock. Only
possible after the use of the slub_lock during dynamic dma creation has been
removed.

Then make sure that the setup of the slab sysfs entries does not race
with kmem_cache_create and kmem_cache destroy.

If a slab cache is removed before we have setup sysfs then simply skip over
the sysfs handling.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Roland Dreier <rdreier@cisco.com>
Signed-off-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

This reverts commit f5b801ac.

The network developers have seen sporadic allocations resulting in objects
coming from unexpected NUMA nodes despite asking for objects from a
specific node.

This is due to get_partial() calling get_any_partial() if partial
slabs are exhausted for a node even if a node was specified and therefore
one would expect allocations only from the specified node.

get_any_partial() sporadically may return a slab from a foreign
node to gradually reduce the size of partial lists on remote nodes
and thereby reduce total memory use for a slab cache.

The behavior is controlled by the remote_defrag_ratio of each cache.

Strictly speaking this is permitted behavior since __GFP_THISNODE was
not specified for the allocation but it is certain surprising.

This patch makes sure that the remote defrag behavior only occurs
if no node was specified.
Signed-off-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

The cacheline with the flags is reachable from the hot paths after the
percpu allocator changes went in. So there is no need anymore to put a
flag into each slab page. Get rid of the SlubDebug flag and use
the flags in kmem_cache instead.
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

If a slab cache is removed before we have setup sysfs then simply skip over
the sysfs handling.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Roland Dreier <rdreier@cisco.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

Small allocations may fail during slab bringup which is fatal. Add a BUG_ON()
so that we fail immediately rather than failing later during sysfs
processing.
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

UL suffix is missing in some constants. Conform to how slab.h uses constants.
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

kmalloc_node() and friends can be passed a constant -1 to indicate
that no choice was made for the node from which the object needs to
come.

Use NUMA_NO_NODE instead of -1.

CC: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

We have been resisting new ftrace plugins and removing existing
ones, and kmemtrace has been superseded by kmem trace events
and perf-kmem, so we remove it.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Acked-by: NPekka Enberg <penberg@cs.helsinki.fi>
Acked-by: NEduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
[ remove kmemtrace from the makefile, handle slob too ]
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>

Before applying this patch, cpuset updates task->mems_allowed and
mempolicy by setting all new bits in the nodemask first, and clearing all
old unallowed bits later.  But in the way, the allocator may find that
there is no node to alloc memory.

The reason is that cpuset rebinds the task's mempolicy, it cleans the
nodes which the allocater can alloc pages on, for example:

(mpol: mempolicy)
	task1			task1's mpol	task2
	alloc page		1
	  alloc on node0? NO	1
				1		change mems from 1 to 0
				1		rebind task1's mpol
				0-1		  set new bits
				0	  	  clear disallowed bits
	  alloc on node1? NO	0
	  ...
	can't alloc page
	  goto oom

This patch fixes this problem by expanding the nodes range first(set newly
allowed bits) and shrink it lazily(clear newly disallowed bits).  So we
use a variable to tell the write-side task that read-side task is reading
nodemask, and the write-side task clears newly disallowed nodes after
read-side task ends the current memory allocation.

[akpm@linux-foundation.org: fix spello]
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Paul Menage <menage@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch is meant to improve the performance of SLUB by moving the local
kmem_cache_node lock into it's own cacheline separate from kmem_cache.
This is accomplished by simply removing the local_node when NUMA is enabled.

On my system with 2 nodes I saw around a 5% performance increase w/
hackbench times dropping from 6.2 seconds to 5.9 seconds on average.  I
suspect the performance gain would increase as the number of nodes
increases, but I do not have the data to currently back that up.

Bugzilla-Reference: http://bugzilla.kernel.org/show_bug.cgi?id=15713
Cc: <stable@kernel.org>
Reported-by: NAlex Shi <alex.shi@intel.com>
Tested-by: NAlex Shi <alex.shi@intel.com>
Acked-by: NYanmin Zhang <yanmin_zhang@linux.intel.com>
Acked-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

The alloc_slab_page() in SLUB uses alloc_pages() if node is '-1'.  This means
that node validity check in alloc_pages_node is unnecessary and we can use
alloc_pages_exact_node() to avoid comparison and branch as commit
6484eb3e ("page allocator: do not check NUMA node ID when the caller
knows the node is valid") did for the page allocator.

Cc: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: NMel Gorman <mel@csn.ul.ie>
Signed-off-by: NMinchan Kim <minchan.kim@gmail.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

commit 94b528d0 (kmemtrace: SLUB hooks for caller-tracking functions)
missed tracing kmalloc_large_node in __kmalloc_node_track_caller. We
should trace it same as __kmalloc_node.
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: NXiaotian Feng <dfeng@redhat.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

I discovered that we can overflow stack if CONFIG_SLUB_DEBUG=y and use slabs
with many objects, since list_slab_objects() and process_slab() use
DECLARE_BITMAP(map, page->objects).

With 65535 bits, we use 8192 bytes of stack ...

Switch these allocations to dynamic allocations.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

Function init_kmem_cache_nodes is incorrect when checking upper limitation of
kmalloc_caches. The breakage was introduced by commit
91efd773 ("dma kmalloc handling fixes").
Acked-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

As suggested by Linus, fix up kmem_ptr_validate() to handle non-kernel pointers
more graciously. The patch changes kmem_ptr_validate() to use the newly
introduced kern_ptr_validate() helper to check that a pointer is a valid kernel
pointer before we attempt to convert it into a 'struct page'.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Acked-by: NChristoph Lameter <cl@linux-foundation.org>
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Constify struct sysfs_ops.

This is part of the ops structure constification
effort started by Arjan van de Ven et al.

Benefits of this constification:

 * prevents modification of data that is shared
   (referenced) by many other structure instances
   at runtime

 * detects/prevents accidental (but not intentional)
   modification attempts on archs that enforce
   read-only kernel data at runtime

 * potentially better optimized code as the compiler
   can assume that the const data cannot be changed

 * the compiler/linker move const data into .rodata
   and therefore exclude them from false sharing
Signed-off-by: NEmese Revfy <re.emese@gmail.com>
Acked-by: NDavid Teigland <teigland@redhat.com>
Acked-by: NMatt Domsch <Matt_Domsch@dell.com>
Acked-by: NMaciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: NHans J. Koch <hjk@linutronix.de>
Acked-by: NPekka Enberg <penberg@cs.helsinki.fi>
Acked-by: NJens Axboe <jens.axboe@oracle.com>
Acked-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Constify struct kset_uevent_ops.

This is part of the ops structure constification
effort started by Arjan van de Ven et al.

Benefits of this constification:

 * prevents modification of data that is shared
   (referenced) by many other structure instances
   at runtime

 * detects/prevents accidental (but not intentional)
   modification attempts on archs that enforce
   read-only kernel data at runtime

 * potentially better optimized code as the compiler
   can assume that the const data cannot be changed

 * the compiler/linker move const data into .rodata
   and therefore exclude them from false sharing
Signed-off-by: NEmese Revfy <re.emese@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The slab tree adds a percpu variable usage case (commit
9dfc6e68 "SLUB: Use this_cpu operations in
slub"), but the percpu tree removes the prefixing of percpu variables (commit
dd17c8f7 "percpu: remove per_cpu__ prefix"),
thus causing the following compilation error:

    CC      mm/slub.o
  mm/slub.c: In function ‘alloc_kmem_cache_cpus’:
  mm/slub.c:2078: error: implicit declaration of function ‘per_cpu_var’
  mm/slub.c:2078: warning: assignment makes pointer from integer without a cast
  make[1]: *** [mm/slub.o] Error 1
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

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: NDavid Rientjes <rientjes@google.com>
Acked-by: NAkinobu Mita <akinobu.mita@gmail.com>
Acked-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>