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Commit e6d0e1dc authored by Wei Yang's avatar Wei Yang Committed by Linus Torvalds
Browse files

mm/slub.c: wrap kmem_cache->cpu_partial in config CONFIG_SLUB_CPU_PARTIAL 

kmem_cache->cpu_partial is just used when CONFIG_SLUB_CPU_PARTIAL is
set, so wrap it with config CONFIG_SLUB_CPU_PARTIAL will save some space
on 32bit arch.

This patch wraps kmem_cache->cpu_partial in config CONFIG_SLUB_CPU_PARTIAL
and wraps its sysfs too.

Link: http://lkml.kernel.org/r/20170502144533.10729-4-richard.weiyang@gmail.com


Signed-off-by: default avatarWei Yang <richard.weiyang@gmail.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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent a93cf07b

include/linux/slub_def.h

+13 −0
Original line number Diff line number Diff line
@@ -86,7 +86,9 @@ struct kmem_cache { 
	int size;		/* The size of an object including meta data */

	int object_size;	/* The size of an object without meta data */

	int offset;		/* Free pointer offset. */

#ifdef CONFIG_SLUB_CPU_PARTIAL

	int cpu_partial;	/* Number of per cpu partial objects to keep around */

#endif

	struct kmem_cache_order_objects oo;



	/* Allocation and freeing of slabs */
@@ -131,6 +133,17 @@ struct kmem_cache { 
	struct kmem_cache_node *node[MAX_NUMNODES];

};



#ifdef CONFIG_SLUB_CPU_PARTIAL

#define slub_cpu_partial(s)		((s)->cpu_partial)

#define slub_set_cpu_partial(s, n)		\

({						\

	slub_cpu_partial(s) = (n);		\

})

#else

#define slub_cpu_partial(s)		(0)

#define slub_set_cpu_partial(s, n)

#endif // CONFIG_SLUB_CPU_PARTIAL



#ifdef CONFIG_SYSFS

#define SLAB_SUPPORTS_SYSFS

void sysfs_slab_release(struct kmem_cache *);

mm/slub.c

+38 −31
Original line number Diff line number Diff line
@@ -1829,7 +1829,7 @@ static void *get_partial_node(struct kmem_cache *s, struct kmem_cache_node *n, 
			stat(s, CPU_PARTIAL_NODE);

		}

		if (!kmem_cache_has_cpu_partial(s)

			|| available > s->cpu_partial / 2)

			|| available > slub_cpu_partial(s) / 2)

			break;



	}
@@ -3404,6 +3404,39 @@ static void set_min_partial(struct kmem_cache *s, unsigned long min) 
	s->min_partial = min;

}



static void set_cpu_partial(struct kmem_cache *s)

{

#ifdef CONFIG_SLUB_CPU_PARTIAL

	/*

	 * cpu_partial determined the maximum number of objects kept in the

	 * per cpu partial lists of a processor.

	 *

	 * Per cpu partial lists mainly contain slabs that just have one

	 * object freed. If they are used for allocation then they can be

	 * filled up again with minimal effort. The slab will never hit the

	 * per node partial lists and therefore no locking will be required.

	 *

	 * This setting also determines

	 *

	 * A) The number of objects from per cpu partial slabs dumped to the

	 *    per node list when we reach the limit.

	 * B) The number of objects in cpu partial slabs to extract from the

	 *    per node list when we run out of per cpu objects. We only fetch

	 *    50% to keep some capacity around for frees.

	 */

	if (!kmem_cache_has_cpu_partial(s))

		s->cpu_partial = 0;

	else if (s->size >= PAGE_SIZE)

		s->cpu_partial = 2;

	else if (s->size >= 1024)

		s->cpu_partial = 6;

	else if (s->size >= 256)

		s->cpu_partial = 13;

	else

		s->cpu_partial = 30;

#endif

}



/*

 * calculate_sizes() determines the order and the distribution of data within

 * a slab object.
@@ -3562,33 +3595,7 @@ static int kmem_cache_open(struct kmem_cache *s, unsigned long flags) 
	 */

	set_min_partial(s, ilog2(s->size) / 2);



	/*

	 * cpu_partial determined the maximum number of objects kept in the

	 * per cpu partial lists of a processor.

	 *

	 * Per cpu partial lists mainly contain slabs that just have one

	 * object freed. If they are used for allocation then they can be

	 * filled up again with minimal effort. The slab will never hit the

	 * per node partial lists and therefore no locking will be required.

	 *

	 * This setting also determines

	 *

	 * A) The number of objects from per cpu partial slabs dumped to the

	 *    per node list when we reach the limit.

	 * B) The number of objects in cpu partial slabs to extract from the

	 *    per node list when we run out of per cpu objects. We only fetch

	 *    50% to keep some capacity around for frees.

	 */

	if (!kmem_cache_has_cpu_partial(s))

		s->cpu_partial = 0;

	else if (s->size >= PAGE_SIZE)

		s->cpu_partial = 2;

	else if (s->size >= 1024)

		s->cpu_partial = 6;

	else if (s->size >= 256)

		s->cpu_partial = 13;

	else

		s->cpu_partial = 30;

	set_cpu_partial(s);



#ifdef CONFIG_NUMA

	s->remote_node_defrag_ratio = 1000;
@@ -3975,7 +3982,7 @@ void __kmemcg_cache_deactivate(struct kmem_cache *s) 
	 * Disable empty slabs caching. Used to avoid pinning offline

	 * memory cgroups by kmem pages that can be freed.

	 */

	s->cpu_partial = 0;

	slub_set_cpu_partial(s, 0);

	s->min_partial = 0;



	/*
@@ -4915,7 +4922,7 @@ SLAB_ATTR(min_partial); 


static ssize_t cpu_partial_show(struct kmem_cache *s, char *buf)

{

	return sprintf(buf, "%u\n", s->cpu_partial);

	return sprintf(buf, "%u\n", slub_cpu_partial(s));

}



static ssize_t cpu_partial_store(struct kmem_cache *s, const char *buf,
@@ -4930,7 +4937,7 @@ static ssize_t cpu_partial_store(struct kmem_cache *s, const char *buf, 
	if (objects && !kmem_cache_has_cpu_partial(s))

		return -EINVAL;



	s->cpu_partial = objects;

	slub_set_cpu_partial(s, objects);

	flush_all(s);

	return length;

}