diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-kernel-slab | 13 | ||||
| -rw-r--r-- | mm/slab.h | 1 | ||||
| -rw-r--r-- | mm/slab_common.c | 37 | ||||
| -rw-r--r-- | mm/slub.c | 2 |
4 files changed, 48 insertions, 5 deletions
diff --git a/Documentation/ABI/testing/sysfs-kernel-slab b/Documentation/ABI/testing/sysfs-kernel-slab index 29601d93a1c2..ed35833ad7f0 100644 --- a/Documentation/ABI/testing/sysfs-kernel-slab +++ b/Documentation/ABI/testing/sysfs-kernel-slab @@ -429,10 +429,15 @@ KernelVersion: 2.6.22 Contact: Pekka Enberg <penberg@cs.helsinki.fi>, Christoph Lameter <cl@linux-foundation.org> Description: - The shrink file is written when memory should be reclaimed from - a cache. Empty partial slabs are freed and the partial list is - sorted so the slabs with the fewest available objects are used - first. + The shrink file is used to reclaim unused slab cache + memory from a cache. Empty per-cpu or partial slabs + are freed and the partial list is sorted so the slabs + with the fewest available objects are used first. + It only accepts a value of "1" on write for shrinking + the cache. Other input values are considered invalid. + Shrinking slab caches might be expensive and can + adversely impact other running applications. So it + should be used with care. What: /sys/kernel/slab/cache/slab_size Date: May 2007 diff --git a/mm/slab.h b/mm/slab.h index 9057b8056b07..5bf615cb3f99 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -174,6 +174,7 @@ int __kmem_cache_shrink(struct kmem_cache *); void __kmemcg_cache_deactivate(struct kmem_cache *s); void __kmemcg_cache_deactivate_after_rcu(struct kmem_cache *s); void slab_kmem_cache_release(struct kmem_cache *); +void kmem_cache_shrink_all(struct kmem_cache *s); struct seq_file; struct file; diff --git a/mm/slab_common.c b/mm/slab_common.c index 807490fe217a..6491c3a41805 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -981,6 +981,43 @@ int kmem_cache_shrink(struct kmem_cache *cachep) } EXPORT_SYMBOL(kmem_cache_shrink); +/** + * kmem_cache_shrink_all - shrink a cache and all memcg caches for root cache + * @s: The cache pointer + */ +void kmem_cache_shrink_all(struct kmem_cache *s) +{ + struct kmem_cache *c; + + if (!IS_ENABLED(CONFIG_MEMCG_KMEM) || !is_root_cache(s)) { + kmem_cache_shrink(s); + return; + } + + get_online_cpus(); + get_online_mems(); + kasan_cache_shrink(s); + __kmem_cache_shrink(s); + + /* + * We have to take the slab_mutex to protect from the memcg list + * modification. + */ + mutex_lock(&slab_mutex); + for_each_memcg_cache(c, s) { + /* + * Don't need to shrink deactivated memcg caches. + */ + if (s->flags & SLAB_DEACTIVATED) + continue; + kasan_cache_shrink(c); + __kmem_cache_shrink(c); + } + mutex_unlock(&slab_mutex); + put_online_mems(); + put_online_cpus(); +} + bool slab_is_available(void) { return slab_state >= UP; diff --git a/mm/slub.c b/mm/slub.c index 8834563cdb4b..66808d3e97d2 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -5298,7 +5298,7 @@ static ssize_t shrink_store(struct kmem_cache *s, const char *buf, size_t length) { if (buf[0] == '1') - kmem_cache_shrink(s); + kmem_cache_shrink_all(s); else return -EINVAL; return length; |