From: Wei Yang <richard.weiyang@xxxxxxxxx> Subject: 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@xxxxxxxxx Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxx> Cc: Pekka Enberg <penberg@xxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/slub_def.h | 13 ++++++ mm/slub.c | 69 ++++++++++++++++++++----------------- 2 files changed, 51 insertions(+), 31 deletions(-) diff -puN include/linux/slub_def.h~mm-slub-wrap-kmem_cache-cpu_partial-in-config-config_slub_cpu_partial include/linux/slub_def.h --- a/include/linux/slub_def.h~mm-slub-wrap-kmem_cache-cpu_partial-in-config-config_slub_cpu_partial +++ a/include/linux/slub_def.h @@ -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 *); diff -puN mm/slub.c~mm-slub-wrap-kmem_cache-cpu_partial-in-config-config_slub_cpu_partial mm/slub.c --- a/mm/slub.c~mm-slub-wrap-kmem_cache-cpu_partial-in-config-config_slub_cpu_partial +++ a/mm/slub.c @@ -1829,7 +1829,7 @@ static void *get_partial_node(struct kme 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_ 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_c */ 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 km * 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 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; } _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
