list_lru: introduce per-memcg lists
There are several FS shrinkers, including super_block::s_shrink, that
keep reclaimable objects in the list_lru structure. Hence to turn them
to memcg-aware shrinkers, it is enough to make list_lru per-memcg.
This patch does the trick. It adds an array of lru lists to the
list_lru_node structure (per-node part of the list_lru), one for each
kmem-active memcg, and dispatches every item addition or removal to the
list corresponding to the memcg which the item is accounted to. So now
the list_lru structure is not just per node, but per node and per memcg.
Not all list_lrus need this feature, so this patch also adds a new
method, list_lru_init_memcg, which initializes a list_lru as memcg
aware. Otherwise (i.e. if initialized with old list_lru_init), the
list_lru won't have per memcg lists.
Just like per memcg caches arrays, the arrays of per-memcg lists are
indexed by memcg_cache_id, so we must grow them whenever
memcg_nr_cache_ids is increased. So we introduce a callback,
memcg_update_all_list_lrus, invoked by memcg_alloc_cache_id if the id
space is full.
The locking is implemented in a manner similar to lruvecs, i.e. we have
one lock per node that protects all lists (both global and per cgroup) on
the node.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Greg Thelen <gthelen@google.com>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
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>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6706e5f..afa55bb 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2572,6 +2572,8 @@
err = memcg_update_all_caches(size);
if (!err)
+ err = memcg_update_all_list_lrus(size);
+ if (!err)
memcg_nr_cache_ids = size;
up_write(&memcg_cache_ids_sem);
@@ -2765,6 +2767,24 @@
memcg_uncharge_kmem(memcg, 1 << order);
page->mem_cgroup = NULL;
}
+
+struct mem_cgroup *__mem_cgroup_from_kmem(void *ptr)
+{
+ struct mem_cgroup *memcg = NULL;
+ struct kmem_cache *cachep;
+ struct page *page;
+
+ page = virt_to_head_page(ptr);
+ if (PageSlab(page)) {
+ cachep = page->slab_cache;
+ if (!is_root_cache(cachep))
+ memcg = cachep->memcg_params->memcg;
+ } else
+ /* page allocated by alloc_kmem_pages */
+ memcg = page->mem_cgroup;
+
+ return memcg;
+}
#endif /* CONFIG_MEMCG_KMEM */
#ifdef CONFIG_TRANSPARENT_HUGEPAGE