lkml.org 
[lkml]   [2020]   [Oct]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH FIX v0] mm: memcg/slab: Uncharge during kmem_cache_free_bulk()
Date
Object cgroup charging is done for all the objects during
allocation, but during freeing, uncharging ends up happening
for only one object in the case of bulk allocation/freeing.

Fix this by having a separate call to uncharge all the
objects from kmem_cache_free_bulk() and by modifying
memcg_slab_free_hook() to take care of bulk uncharging.

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
---
mm/slab.c | 2 +-
mm/slab.h | 42 +++++++++++++++++++++++++++---------------
mm/slub.c | 3 ++-
3 files changed, 30 insertions(+), 17 deletions(-)

diff --git a/mm/slab.c b/mm/slab.c
index f658e86ec8cee..5c70600d8b1cc 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3440,7 +3440,7 @@ void ___cache_free(struct kmem_cache *cachep, void *objp,
memset(objp, 0, cachep->object_size);
kmemleak_free_recursive(objp, cachep->flags);
objp = cache_free_debugcheck(cachep, objp, caller);
- memcg_slab_free_hook(cachep, virt_to_head_page(objp), objp);
+ memcg_slab_free_hook(cachep, &objp, 1);

/*
* Skip calling cache_free_alien() when the platform is not numa.
diff --git a/mm/slab.h b/mm/slab.h
index 6cc323f1313af..6dd4b702888a7 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -345,30 +345,42 @@ static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
obj_cgroup_put(objcg);
}

-static inline void memcg_slab_free_hook(struct kmem_cache *s, struct page *page,
- void *p)
+static inline void memcg_slab_free_hook(struct kmem_cache *s_orig,
+ void **p, int objects)
{
+ struct kmem_cache *s;
struct obj_cgroup *objcg;
+ struct page *page;
unsigned int off;
+ int i;

if (!memcg_kmem_enabled())
return;

- if (!page_has_obj_cgroups(page))
- return;
+ for (i = 0; i < objects; i++) {
+ if (unlikely(!p[i]))
+ continue;

- off = obj_to_index(s, page, p);
- objcg = page_obj_cgroups(page)[off];
- page_obj_cgroups(page)[off] = NULL;
+ page = virt_to_head_page(p[i]);
+ if (!page_has_obj_cgroups(page))
+ continue;

- if (!objcg)
- return;
+ if (!s_orig)
+ s = page->slab_cache;
+ else
+ s = s_orig;

- obj_cgroup_uncharge(objcg, obj_full_size(s));
- mod_objcg_state(objcg, page_pgdat(page), cache_vmstat_idx(s),
- -obj_full_size(s));
+ off = obj_to_index(s, page, p[i]);
+ objcg = page_obj_cgroups(page)[off];
+ if (!objcg)
+ continue;

- obj_cgroup_put(objcg);
+ page_obj_cgroups(page)[off] = NULL;
+ obj_cgroup_uncharge(objcg, obj_full_size(s));
+ mod_objcg_state(objcg, page_pgdat(page), cache_vmstat_idx(s),
+ -obj_full_size(s));
+ obj_cgroup_put(objcg);
+ }
}

#else /* CONFIG_MEMCG_KMEM */
@@ -406,8 +418,8 @@ static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
{
}

-static inline void memcg_slab_free_hook(struct kmem_cache *s, struct page *page,
- void *p)
+static inline void memcg_slab_free_hook(struct kmem_cache *s,
+ void **p, int objects)
{
}
#endif /* CONFIG_MEMCG_KMEM */
diff --git a/mm/slub.c b/mm/slub.c
index 6d3574013b2f8..0cbe67f13946e 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3091,7 +3091,7 @@ static __always_inline void do_slab_free(struct kmem_cache *s,
struct kmem_cache_cpu *c;
unsigned long tid;

- memcg_slab_free_hook(s, page, head);
+ memcg_slab_free_hook(s, &head, 1);
redo:
/*
* Determine the currently cpus per cpu slab.
@@ -3253,6 +3253,7 @@ void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p)
if (WARN_ON(!size))
return;

+ memcg_slab_free_hook(s, p, size);
do {
struct detached_freelist df;

--
2.26.2
\
 
 \ /
  Last update: 2020-10-09 08:05    [W:0.404 / U:0.920 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site