[PATCH 2/3] mm, slub: count freed pages via rcu as this task's reclaimed_slab

From: Joonsoo Kim
Date: Mon Apr 08 2013 - 21:20:51 EST

Currently, freed pages via rcu is not counted for reclaimed_slab, because
it is freed in rcu context, not current task context. But, this free is
initiated by this task, so counting this into this task's reclaimed_slab
is meaningful to decide whether we continue reclaim, or not.
So change code to count these pages for this task's reclaimed_slab.

Cc: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: Matt Mackall <mpm@xxxxxxxxxxx>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>

diff --git a/mm/slub.c b/mm/slub.c
index 4aec537..16fd2d5 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1409,8 +1409,6 @@ static void __free_slab(struct kmem_cache *s, struct page *page)

memcg_release_pages(s, order);
- if (current->reclaim_state)
- current->reclaim_state->reclaimed_slab += pages;
__free_memcg_kmem_pages(page, order);

@@ -1431,6 +1429,8 @@ static void rcu_free_slab(struct rcu_head *h)

static void free_slab(struct kmem_cache *s, struct page *page)
+ int pages = 1 << compound_order(page);
if (unlikely(s->flags & SLAB_DESTROY_BY_RCU)) {
struct rcu_head *head;

@@ -1450,6 +1450,9 @@ static void free_slab(struct kmem_cache *s, struct page *page)
call_rcu(head, rcu_free_slab);
} else
__free_slab(s, page);
+ if (current->reclaim_state)
+ current->reclaim_state->reclaimed_slab += pages;

static void discard_slab(struct kmem_cache *s, struct page *page)

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