SLOB has no node specific management structures.

Do not provide the defintions for node management structures for SLOB.

Signed-off-by: Christoph Lameter <cl@linux.com>
Reported-by: Wu Fengguang <fengguang.wu@intel.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
slub: use new node functions

Make use of the new node functions in mm/slab.h to reduce code size and
simplify.

Signed-off-by: Christoph Lameter <cl@linux.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
slub-use-new-node-functions-checkpatch-fixes

ERROR: space required before the open parenthesis '('
#189: FILE: mm/slub.c:4350:
+	for(node = 0; node < nr_node_ids; node++)

total: 1 errors, 0 warnings, 192 lines checked

./patches/slub-use-new-node-functions.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
slub-use-new-node-functions-fix

On Wed, 11 Jun 2014, David Rientjes wrote:

> > +	for_each_kmem_cache_node(s, node, n) {
> >
> >  		free_partial(s, n);
> >  		if (n->nr_partial || slabs_node(s, node))
>
> Newline not removed?

Ok got through the file and removed all the lines after
for_each_kmem_cache_node.

>
> > @@ -3407,11 +3401,7 @@ int __kmem_cache_shrink(struct kmem_cach
> >  		return -ENOMEM;
> >
> >  	flush_all(s);
> > -	for_each_node_state(node, N_NORMAL_MEMORY) {
> > -		n = get_node(s, node);
> > -
> > -		if (!n->nr_partial)
> > -			continue;
> > +	for_each_kmem_cache_node(s, node, n) {
> >
> >  		for (i = 0; i < objects; i++)
> >  			INIT_LIST_HEAD(slabs_by_inuse + i);
>
> Is there any reason not to keep the !n->nr_partial check to avoid taking
> n->list_lock unnecessarily?

No this was simply a mistake the check needs to be preserved.

Subject: slub: Fix up earlier patch

Signed-off-by: Christoph Lameter <cl@linux.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
slab: use get_node() and kmem_cache_node() functions

Use the two functions to simplify the code avoiding numerous explicit
checks coded checking for a certain node to be online.

Get rid of various repeated calculations of kmem_cache_node structures.

Signed-off-by: Christoph Lameter <cl@linux.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
slab-use-get_node-and-kmem_cache_node-functions-fix

On Thu, 12 Jun 2014, Joonsoo Kim wrote:

> > @@ -3759,8 +3746,8 @@ fail:
> >  		/* Cache is not active yet. Roll back what we did */
> >  		node--;
> >  		while (node >= 0) {
> > -			if (cachep->node[node]) {
> > -				n = cachep->node[node];
> > +			if (get_node(cachep, node)) {
> > +				n = get_node(cachep, node);
>
> Could you do this as following?
>
> n = get_node(cachep, node);
> if (n) {
>         ...
> }

Sure....

Subject: slab: Fixes to earlier patch

Signed-off-by: Christoph Lameter <cl@linux.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
slab-use-get_node-and-kmem_cache_node-functions-fix-2

mm/slab.c: In function 'slab_set_debugobj_lock_classes':
mm/slab.c:524: error: 'h' undeclared (first use in this function)
mm/slab.c:524: error: (Each undeclared identifier is reported only once
mm/slab.c:524: error: for each function it appears in.)
mm/slab.c:524: warning: left-hand operand of comma expression has no effect
mm/slab.c: In function 'cpuup_prepare':
mm/slab.c:1308: warning: passing argument 2 of 'slab_set_debugobj_lock_classes_node' makes pointer from integer without a cast
mm/slab.c:513: note: expected 'struct kmem_cache_node *' but argument is of type 'int'

Cc: Christoph Lameter <cl@gentwo.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
slab-use-get_node-and-kmem_cache_node-functions-fix-2-fix

Cc: Christoph Lameter <cl@linux.com>
Reported-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm: slab.h: wrap the whole file with guarding macro

Guarding section:
	#ifndef MM_SLAB_H
	#define MM_SLAB_H
	...
	#endif
currently doesn't cover the whole mm/slab.h. It seems like it was
done unintentionally.

Wrap the whole file by moving closing #endif to the end of it.

Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm, slub: mark resiliency_test as init text

resiliency_test() is only called for bootstrap, so it may be moved to
init.text and freed after boot.

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm: slub: SLUB_DEBUG=n: use the same alloc/free hooks as for SLUB_DEBUG=y

There are two versions of alloc/free hooks now - one for
CONFIG_SLUB_DEBUG=y and another one for CONFIG_SLUB_DEBUG=n.

I see no reason why calls to other debugging subsystems (LOCKDEP,
DEBUG_ATOMIC_SLEEP, KMEMCHECK and FAILSLAB) are hidden under SLUB_DEBUG.
All this features should work regardless of SLUB_DEBUG config, as all of
them already have own Kconfig options.

This also fixes failslab for CONFIG_SLUB_DEBUG=n configuration.  It simply
has not worked before because should_failslab() call was in a hook hidden
under "#ifdef CONFIG_SLUB_DEBUG #else".

Note: There is one concealed change in allocation path for SLUB_DEBUG=n
and all other debugging features disabled.  The might_sleep_if() call can
generate some code even if DEBUG_ATOMIC_SLEEP=n.  For PREEMPT_VOLUNTARY=y
might_sleep() inserts _cond_resched() call, but I think it should be ok.

Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
slab: add unlikely macro to help compiler

This patchset does some cleanup and tries to remove lockdep annotation.

Patches 1~2 are just for really really minor improvement.
Patches 3~9 are for clean-up and removing lockdep annotation.

There are two cases that lockdep annotation is needed in SLAB.
1) holding two node locks
2) holding two array cache(alien cache) locks

I looked at the code and found that we can avoid these cases without any
negative effect.

1) occurs if freeing object makes new free slab and we decide to
   destroy it.  Although we don't need to hold the lock during destroying
   a slab, current code do that.  Destroying a slab without holding the
   lock would help the reduction of the lock contention.  To do it, I
   change the implementation that new free slab is destroyed after
   releasing the lock.

2) occurs on similar situation.  When we free object from non-local
   node, we put this object to alien cache with holding the alien cache
   lock.  If alien cache is full, we try to flush alien cache to proper
   node cache, and, in this time, new free slab could be made.  Destroying
   it would be started and we will free metadata object which comes from
   another node.  In this case, we need another node's alien cache lock to
   free object.  This forces us to hold two array cache locks and then we
   need lockdep annotation although they are always different locks and
   deadlock cannot be possible.  To prevent this situation, I use same way
   as 1).

In this way, we can avoid 1) and 2) cases, and then, can remove lockdep
annotation. As short stat noted, this makes SLAB code much simpler.

This patch (of 9):

slab_should_failslab() is called on every allocation, so to optimize it is
reasonable.  We normally don't allocate from kmem_cache.  It is just used
when new kmem_cache is created, so it's very rare case.  Therefore, add
unlikely macro to help compiler optimization.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
slab: move up code to get kmem_cache_node in free_block()

node isn't changed, so we don't need to retreive this structure everytime
we move the object.  Maybe compiler do this optimization, but making it
explicitly is better.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
slab: defer slab_destroy in free_block()

In free_block(), if freeing object makes new free slab and number of
free_objects exceeds free_limit, we start to destroy this new free slab
with holding the kmem_cache node lock.  Holding the lock is useless and,
generally, holding a lock as least as possible is good thing.  I never
measure performance effect of this, but we'd be better not to hold the
lock as much as possible.

Commented by Christoph:
  This is also good because kmem_cache_free is no longer called while
  holding the node lock. So we avoid one case of recursion.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
slab-defer-slab_destroy-in-free_block-v4

Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
slab: factor out initialization of array cache

Factor out initialization of array cache to use it in following patch.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
slab: introduce alien_cache

Currently, we use array_cache for alien_cache.  Although they are mostly
similar, there is one difference, that is, need for spinlock.  We don't
need spinlock for array_cache itself, but to use array_cache for
alien_cache, array_cache structure should have spinlock.  This is needless
overhead, so removing it would be better.  This patch prepare it by
introducing alien_cache and using it.  In the following patch, we remove
spinlock in array_cache.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
slab: use the lock on alien_cache, instead of the lock on array_cache

Now, we have separate alien_cache structure, so it'd be better to hold the
lock on alien_cache while manipulating alien_cache.  After that, we don't
need the lock on array_cache, so remove it.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
slab: destroy a slab without holding any alien cache lock

I haven't heard that this alien cache lock is contended, but to reduce
chance of contention would be better generally.  And with this change, we
can simplify complex lockdep annotation in slab code.  In the following
patch, it will be implemented.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
slab: remove a useless lockdep annotation

Now, there is no code to hold two lock simultaneously, since we don't call
slab_destroy() with holding any lock.  So, lockdep annotation is useless
now.  Remove it.

v2: don't remove BAD_ALIEN_MAGIC in this patch. It will be removed
    in the following patch.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>