+ slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch added to -mm tree

+ slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch added to -mm tree

[akpm]

The patch titled
     Subject: slub bulk alloc: extract objects from the per cpu slab
has been added to the -mm tree.  Its filename is
     slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/SubmitChecklist when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Christoph Lameter <cl@linux.com>
Subject: slub bulk alloc: extract objects from the per cpu slab

First piece: acceleration of retrieval of per cpu objects

If we are allocating lots of objects then it is advantageous to disable
interrupts and avoid the this_cpu_cmpxchg() operation to get these objects
faster.  Note that we cannot do the fast operation if debugging is
enabled.  Note also that the requirement of having interrupts disabled
avoids having to do processor flag operations.

Allocate as many objects as possible in the fast way and then fall back to
the generic implementation for the rest of the objects.

Signed-off-by: Christoph Lameter <cl@linux.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.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>
---

 mm/slub.c |   27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff -puN mm/slub.c~slub-bulk-alloc-extract-objects-from-the-per-cpu-slab mm/slub.c
--- a/mm/slub.c~slub-bulk-alloc-extract-objects-from-the-per-cpu-slab
+++ a/mm/slub.c
@@ -2759,7 +2759,32 @@ EXPORT_SYMBOL(kmem_cache_free_bulk);
 bool kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
 								void **p)
 {
-	return kmem_cache_alloc_bulk(s, flags, size, p);
+	if (!kmem_cache_debug(s)) {
+		struct kmem_cache_cpu *c;
+
+		/* Drain objects in the per cpu slab */
+		local_irq_disable();
+		c = this_cpu_ptr(s->cpu_slab);
+
+		while (size) {
+			void *object = c->freelist;
+
+			if (!object)
+				break;
+
+			c->freelist = get_freepointer(s, object);
+			*p++ = object;
+			size--;
+
+			if (unlikely(flags & __GFP_ZERO))
+				memset(object, 0, s->object_size);
+		}
+		c->tid = next_tid(c->tid);
+
+		local_irq_enable();
+	}
+
+	return __kmem_cache_alloc_bulk(s, flags, size, p);
 }
 EXPORT_SYMBOL(kmem_cache_alloc_bulk);
 
_

Patches currently in -mm which might be from cl@linux.com are

mm-slub-parse-slub_debug-o-option-in-switch-statement.patch
mm-slab-correct-config-option-in-comment.patch
slub-use-bool-function-return-values-of-true-false-not-1-0.patch
slab-infrastructure-for-bulk-object-allocation-and-freeing-v3.patch
slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch
mm-remove-gfp_thisnode.patch
mm-thp-really-limit-transparent-hugepage-allocation-to-local-node.patch
kernel-cpuset-remove-exception-for-__gfp_thisnode.patch
mm-consolidate-all-page-flags-helpers-in-linux-page-flagsh.patch
page-flags-trivial-cleanup-for-pagetrans-helpers.patch
page-flags-introduce-page-flags-policies-wrt-compound-pages.patch
page-flags-define-pg_locked-behavior-on-compound-pages.patch
page-flags-define-behavior-of-fs-io-related-flags-on-compound-pages.patch
page-flags-define-behavior-of-lru-related-flags-on-compound-pages.patch
page-flags-define-behavior-slb-related-flags-on-compound-pages.patch
page-flags-define-behavior-of-xen-related-flags-on-compound-pages.patch
page-flags-define-pg_reserved-behavior-on-compound-pages.patch
page-flags-define-pg_swapbacked-behavior-on-compound-pages.patch
page-flags-define-pg_swapcache-behavior-on-compound-pages.patch
page-flags-define-pg_mlocked-behavior-on-compound-pages.patch
page-flags-define-pg_uncached-behavior-on-compound-pages.patch
page-flags-define-pg_uptodate-behavior-on-compound-pages.patch
page-flags-look-on-head-page-if-the-flag-is-encoded-in-page-mapping.patch
mm-sanitize-page-mapping-for-tail-pages.patch
mm-sanitize-page-mapping-for-tail-pages-v2.patch
allow-compaction-of-unevictable-pages.patch
document-interaction-between-compaction-and-the-unevictable-lru.patch
document-interaction-between-compaction-and-the-unevictable-lru-fix.patch
mm-vmalloc-fix-possible-exhaustion-of-vmalloc-space-caused-by-vm_map_ram-allocator.patch
mm-vmalloc-occupy-newly-allocated-vmap-block-just-after-allocation.patch
mm-vmalloc-get-rid-of-dirty-bitmap-inside-vmap_block-structure.patch
mm-uninline-and-cleanup-page-mapping-related-helpers.patch
linux-next.patch

Re: + slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch added to -mm tree

[Joonsoo Kim]

On Wed, Apr 08, 2015 at 03:53:13PM -0700, akpm@linux-foundation.org wrote:
> 
> The patch titled
>      Subject: slub bulk alloc: extract objects from the per cpu slab
> has been added to the -mm tree.  Its filename is
>      slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch
> 
> This patch should soon appear at
>     http://ozlabs.org/~akpm/mmots/broken-out/slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch
> and later at
>     http://ozlabs.org/~akpm/mmotm/broken-out/slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch
> 
> Before you just go and hit "reply", please:
>    a) Consider who else should be cc'ed
>    b) Prefer to cc a suitable mailing list as well
>    c) Ideally: find the original patch on the mailing list and do a
>       reply-to-all to that, adding suitable additional cc's
> 
> *** Remember to use Documentation/SubmitChecklist when testing your code ***
> 
> The -mm tree is included into linux-next and is updated
> there every 3-4 working days
> 
> ------------------------------------------------------
> From: Christoph Lameter <cl@linux.com>
> Subject: slub bulk alloc: extract objects from the per cpu slab
> 
> First piece: acceleration of retrieval of per cpu objects
> 
> If we are allocating lots of objects then it is advantageous to disable
> interrupts and avoid the this_cpu_cmpxchg() operation to get these objects
> faster.  Note that we cannot do the fast operation if debugging is
> enabled.  Note also that the requirement of having interrupts disabled
> avoids having to do processor flag operations.
> 
> Allocate as many objects as possible in the fast way and then fall back to
> the generic implementation for the rest of the objects.
> 
> Signed-off-by: Christoph Lameter <cl@linux.com>
> Cc: Jesper Dangaard Brouer <brouer@redhat.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>
> ---
> 
>  mm/slub.c |   27 ++++++++++++++++++++++++++-
>  1 file changed, 26 insertions(+), 1 deletion(-)
> 
> diff -puN mm/slub.c~slub-bulk-alloc-extract-objects-from-the-per-cpu-slab mm/slub.c
> --- a/mm/slub.c~slub-bulk-alloc-extract-objects-from-the-per-cpu-slab
> +++ a/mm/slub.c
> @@ -2759,7 +2759,32 @@ EXPORT_SYMBOL(kmem_cache_free_bulk);
>  bool kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
>  								void **p)
>  {
> -	return kmem_cache_alloc_bulk(s, flags, size, p);
> +	if (!kmem_cache_debug(s)) {
> +		struct kmem_cache_cpu *c;
> +
> +		/* Drain objects in the per cpu slab */
> +		local_irq_disable();
> +		c = this_cpu_ptr(s->cpu_slab);
> +
> +		while (size) {
> +			void *object = c->freelist;
> +
> +			if (!object)
> +				break;
> +
> +			c->freelist = get_freepointer(s, object);
> +			*p++ = object;
> +			size--;
> +
> +			if (unlikely(flags & __GFP_ZERO))
> +				memset(object, 0, s->object_size);
> +		}
> +		c->tid = next_tid(c->tid);
> +
> +		local_irq_enable();
> +	}
> +
> +	return __kmem_cache_alloc_bulk(s, flags, size, p);

Hello,

So, if __kmem_cache_alloc_bulk() fails, all allocated objects in array
should be freed, but, __kmem_cache_alloc_bulk() can't know
about objects allocated by this slub specific kmem_cache_alloc_bulk()
function. Please fix it.

Thanks.

Re: + slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch added to -mm tree

[Joonsoo Kim]

On Wed, Apr 08, 2015 at 03:53:13PM -0700, akpm@linux-foundation.org wrote:
> 
> The patch titled
>      Subject: slub bulk alloc: extract objects from the per cpu slab
> has been added to the -mm tree.  Its filename is
>      slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch
> 
> This patch should soon appear at
>     http://ozlabs.org/~akpm/mmots/broken-out/slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch
> and later at
>     http://ozlabs.org/~akpm/mmotm/broken-out/slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch
> 
> Before you just go and hit "reply", please:
>    a) Consider who else should be cc'ed
>    b) Prefer to cc a suitable mailing list as well
>    c) Ideally: find the original patch on the mailing list and do a
>       reply-to-all to that, adding suitable additional cc's
> 
> *** Remember to use Documentation/SubmitChecklist when testing your code ***
> 
> The -mm tree is included into linux-next and is updated
> there every 3-4 working days
> 
> ------------------------------------------------------
> From: Christoph Lameter <cl@linux.com>
> Subject: slub bulk alloc: extract objects from the per cpu slab
> 
> First piece: acceleration of retrieval of per cpu objects
> 
> If we are allocating lots of objects then it is advantageous to disable
> interrupts and avoid the this_cpu_cmpxchg() operation to get these objects
> faster.  Note that we cannot do the fast operation if debugging is
> enabled.  Note also that the requirement of having interrupts disabled
> avoids having to do processor flag operations.
> 
> Allocate as many objects as possible in the fast way and then fall back to
> the generic implementation for the rest of the objects.
> 
> Signed-off-by: Christoph Lameter <cl@linux.com>
> Cc: Jesper Dangaard Brouer <brouer@redhat.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>
> ---
> 
>  mm/slub.c |   27 ++++++++++++++++++++++++++-
>  1 file changed, 26 insertions(+), 1 deletion(-)
> 
> diff -puN mm/slub.c~slub-bulk-alloc-extract-objects-from-the-per-cpu-slab mm/slub.c
> --- a/mm/slub.c~slub-bulk-alloc-extract-objects-from-the-per-cpu-slab
> +++ a/mm/slub.c
> @@ -2759,7 +2759,32 @@ EXPORT_SYMBOL(kmem_cache_free_bulk);
>  bool kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
>  								void **p)
>  {
> -	return kmem_cache_alloc_bulk(s, flags, size, p);
> +	if (!kmem_cache_debug(s)) {
> +		struct kmem_cache_cpu *c;
> +
> +		/* Drain objects in the per cpu slab */
> +		local_irq_disable();
> +		c = this_cpu_ptr(s->cpu_slab);
> +
> +		while (size) {
> +			void *object = c->freelist;
> +
> +			if (!object)
> +				break;
> +
> +			c->freelist = get_freepointer(s, object);
> +			*p++ = object;
> +			size--;
> +
> +			if (unlikely(flags & __GFP_ZERO))
> +				memset(object, 0, s->object_size);

Ahh... and, how about doing memset after irq is enabled?

Thanks.

Re: + slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch added to -mm tree

[Jesper Dangaard Brouer]

On Tue, 9 Jun 2015 09:26:39 +0900
Joonsoo Kim <iamjoonsoo.kim@lge.com> wrote:

> On Wed, Apr 08, 2015 at 03:53:13PM -0700, akpm@linux-foundation.org wrote:
> > 
> > The patch titled
> >      Subject: slub bulk alloc: extract objects from the per cpu slab
> > has been added to the -mm tree.  Its filename is
> >      slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch
> > 
> > This patch should soon appear at
> >     http://ozlabs.org/~akpm/mmots/broken-out/slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch
> > and later at
> >     http://ozlabs.org/~akpm/mmotm/broken-out/slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch
> > 
> > Before you just go and hit "reply", please:
> >    a) Consider who else should be cc'ed
> >    b) Prefer to cc a suitable mailing list as well
> >    c) Ideally: find the original patch on the mailing list and do a
> >       reply-to-all to that, adding suitable additional cc's
> > 
> > *** Remember to use Documentation/SubmitChecklist when testing your code ***
> > 
> > The -mm tree is included into linux-next and is updated
> > there every 3-4 working days
> > 
> > ------------------------------------------------------
> > From: Christoph Lameter <cl@linux.com>
> > Subject: slub bulk alloc: extract objects from the per cpu slab
> > 
> > First piece: acceleration of retrieval of per cpu objects
> > 
> > If we are allocating lots of objects then it is advantageous to disable
> > interrupts and avoid the this_cpu_cmpxchg() operation to get these objects
> > faster.  Note that we cannot do the fast operation if debugging is
> > enabled.  Note also that the requirement of having interrupts disabled
> > avoids having to do processor flag operations.
> > 
> > Allocate as many objects as possible in the fast way and then fall back to
> > the generic implementation for the rest of the objects.
> > 
> > Signed-off-by: Christoph Lameter <cl@linux.com>
> > Cc: Jesper Dangaard Brouer <brouer@redhat.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>
> > ---
> > 
> >  mm/slub.c |   27 ++++++++++++++++++++++++++-
> >  1 file changed, 26 insertions(+), 1 deletion(-)
> > 
> > diff -puN mm/slub.c~slub-bulk-alloc-extract-objects-from-the-per-cpu-slab mm/slub.c
> > --- a/mm/slub.c~slub-bulk-alloc-extract-objects-from-the-per-cpu-slab
> > +++ a/mm/slub.c
> > @@ -2759,7 +2759,32 @@ EXPORT_SYMBOL(kmem_cache_free_bulk);
> >  bool kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
> >  								void **p)
> >  {
> > -	return kmem_cache_alloc_bulk(s, flags, size, p);
> > +	if (!kmem_cache_debug(s)) {
> > +		struct kmem_cache_cpu *c;
> > +
> > +		/* Drain objects in the per cpu slab */
> > +		local_irq_disable();
> > +		c = this_cpu_ptr(s->cpu_slab);
> > +
> > +		while (size) {
> > +			void *object = c->freelist;
> > +
> > +			if (!object)
> > +				break;
> > +
> > +			c->freelist = get_freepointer(s, object);
> > +			*p++ = object;
> > +			size--;
> > +
> > +			if (unlikely(flags & __GFP_ZERO))
> > +				memset(object, 0, s->object_size);
> > +		}
> > +		c->tid = next_tid(c->tid);
> > +
> > +		local_irq_enable();
> > +	}
> > +
> > +	return __kmem_cache_alloc_bulk(s, flags, size, p);
> 
> Hello,
> 
> So, if __kmem_cache_alloc_bulk() fails, all allocated objects in array
> should be freed, but, __kmem_cache_alloc_bulk() can't know
> about objects allocated by this slub specific kmem_cache_alloc_bulk()
> function. Please fix it.

Check, I've already noticed this, and have fixed it in my local git
tree. 

How do I submit a fix to AKPM? (do I replace the commit/patch, or do I
apply a patch on top)

(And as you also noticed, I've also moved the memset out of the loop,
after irq_enable)

-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Sr. Network Kernel Developer at Red Hat
  Author of http://www.iptv-analyzer.org
  LinkedIn: http://www.linkedin.com/in/brouer

+ slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch added to -mm tree

[akpm]

The patch titled
     Subject: slub bulk alloc: extract objects from the per cpu slab
has been added to the -mm tree.  Its filename is
     slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/SubmitChecklist when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Jesper Dangaard Brouer <brouer@redhat.com>
Subject: slub bulk alloc: extract objects from the per cpu slab

First piece: acceleration of retrieval of per cpu objects

If we are allocating lots of objects then it is advantageous to disable
interrupts and avoid the this_cpu_cmpxchg() operation to get these objects
faster.

Note that we cannot do the fast operation if debugging is enabled, because
we would have to add extra code to do all the debugging checks.  And it
would not be fast anyway.

Note also that the requirement of having interrupts disabled avoids having
to do processor flag operations.

Allocate as many objects as possible in the fast way and then fall back to
the generic implementation for the rest of the objects.

Measurements on CPU CPU i7-4790K @ 4.00GHz
Baseline normal fastpath (alloc+free cost): 42 cycles(tsc) 10.554 ns

Bulk- fallback                   - this-patch
  1 -  57 cycles(tsc) 14.432 ns  -  48 cycles(tsc) 12.155 ns  improved 15.8%
  2 -  50 cycles(tsc) 12.746 ns  -  37 cycles(tsc)  9.390 ns  improved 26.0%
  3 -  48 cycles(tsc) 12.180 ns  -  33 cycles(tsc)  8.417 ns  improved 31.2%
  4 -  48 cycles(tsc) 12.015 ns  -  32 cycles(tsc)  8.045 ns  improved 33.3%
  8 -  46 cycles(tsc) 11.526 ns  -  30 cycles(tsc)  7.699 ns  improved 34.8%
 16 -  45 cycles(tsc) 11.418 ns  -  32 cycles(tsc)  8.205 ns  improved 28.9%
 30 -  80 cycles(tsc) 20.246 ns  -  73 cycles(tsc) 18.328 ns  improved  8.8%
 32 -  79 cycles(tsc) 19.946 ns  -  72 cycles(tsc) 18.208 ns  improved  8.9%
 34 -  78 cycles(tsc) 19.659 ns  -  71 cycles(tsc) 17.987 ns  improved  9.0%
 48 -  86 cycles(tsc) 21.516 ns  -  82 cycles(tsc) 20.566 ns  improved  4.7%
 64 -  93 cycles(tsc) 23.423 ns  -  89 cycles(tsc) 22.480 ns  improved  4.3%
128 - 100 cycles(tsc) 25.170 ns  -  99 cycles(tsc) 24.871 ns  improved  1.0%
158 - 102 cycles(tsc) 25.549 ns  - 101 cycles(tsc) 25.375 ns  improved  1.0%
250 - 101 cycles(tsc) 25.344 ns  - 100 cycles(tsc) 25.182 ns  improved  1.0%

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.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>
---

 mm/slub.c |   49 +++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 47 insertions(+), 2 deletions(-)

diff -puN mm/slub.c~slub-bulk-alloc-extract-objects-from-the-per-cpu-slab mm/slub.c
--- a/mm/slub.c~slub-bulk-alloc-extract-objects-from-the-per-cpu-slab
+++ a/mm/slub.c
@@ -2750,16 +2750,61 @@ void kmem_cache_free(struct kmem_cache *
 }
 EXPORT_SYMBOL(kmem_cache_free);
 
+/* Note that interrupts must be enabled when calling this function. */
 void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p)
 {
 	__kmem_cache_free_bulk(s, size, p);
 }
 EXPORT_SYMBOL(kmem_cache_free_bulk);
 
+/* Note that interrupts must be enabled when calling this function. */
 bool kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
-								void **p)
+			   void **p)
 {
-	return __kmem_cache_alloc_bulk(s, flags, size, p);
+	struct kmem_cache_cpu *c;
+	int i;
+
+	/* Debugging fallback to generic bulk */
+	if (kmem_cache_debug(s))
+		return __kmem_cache_alloc_bulk(s, flags, size, p);
+
+	/*
+	 * Drain objects in the per cpu slab, while disabling local
+	 * IRQs, which protects against PREEMPT and interrupts
+	 * handlers invoking normal fastpath.
+	 */
+	local_irq_disable();
+	c = this_cpu_ptr(s->cpu_slab);
+
+	for (i = 0; i < size; i++) {
+		void *object = c->freelist;
+
+		if (!object)
+			break;
+
+		c->freelist = get_freepointer(s, object);
+		p[i] = object;
+	}
+	c->tid = next_tid(c->tid);
+	local_irq_enable();
+
+	/* Clear memory outside IRQ disabled fastpath loop */
+	if (unlikely(flags & __GFP_ZERO)) {
+		int j;
+
+		for (j = 0; j < i; j++)
+			memset(p[j], 0, s->object_size);
+	}
+
+	/* Fallback to single elem alloc */
+	for (; i < size; i++) {
+		void *x = p[i] = kmem_cache_alloc(s, flags);
+		if (unlikely(!x)) {
+			__kmem_cache_free_bulk(s, i, p);
+			return false;
+		}
+	}
+	return true;
 }
 EXPORT_SYMBOL(kmem_cache_alloc_bulk);
 
_

Patches currently in -mm which might be from brouer@redhat.com are

slub-fix-spelling-succedd-to-succeed.patch
slab-infrastructure-for-bulk-object-allocation-and-freeing.patch
slub-bulk-alloc-extract-objects-from-the-per-cpu-slab.patch
slub-improve-bulk-alloc-strategy.patch
slub-initial-bulk-free-implementation.patch
slub-add-support-for-kmem_cache_debug-in-bulk-calls.patch