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authorRoman Gushchin <guro@fb.com>2020-12-01 13:58:28 -0800
committerAlexei Starovoitov <ast@kernel.org>2020-12-02 18:28:06 -0800
commit270c6a71460e12b07b1dcadf7457ff95b6c6e8f4 (patch)
treee8193c62193e2da704a7fcd98d1961e5a03703a1 /mm/slab.h
parentbcfe06bf2622f7c4899468e427683aec49070687 (diff)
mm: memcontrol/slab: Use helpers to access slab page's memcg_data
To gather all direct accesses to struct page's memcg_data field in one place, let's introduce 3 new helpers to use in the slab accounting code: struct obj_cgroup **page_objcgs(struct page *page); struct obj_cgroup **page_objcgs_check(struct page *page); bool set_page_objcgs(struct page *page, struct obj_cgroup **objcgs); They are similar to the corresponding API for generic pages, except that the setter can return false, indicating that the value has been already set from a different thread. Signed-off-by: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Link: https://lkml.kernel.org/r/20201027001657.3398190-3-guro@fb.com Link: https://lore.kernel.org/bpf/20201201215900.3569844-3-guro@fb.com
Diffstat (limited to 'mm/slab.h')
-rw-r--r--mm/slab.h35
1 files changed, 8 insertions, 27 deletions
diff --git a/mm/slab.h b/mm/slab.h
index e2535cee0d33..9a54a0cb5cca 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -239,28 +239,12 @@ static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t fla
}
#ifdef CONFIG_MEMCG_KMEM
-static inline struct obj_cgroup **page_obj_cgroups(struct page *page)
-{
- /*
- * Page's memory cgroup and obj_cgroups vector are sharing the same
- * space. To distinguish between them in case we don't know for sure
- * that the page is a slab page (e.g. page_cgroup_ino()), let's
- * always set the lowest bit of obj_cgroups.
- */
- return (struct obj_cgroup **)(page->memcg_data & ~0x1UL);
-}
-
-static inline bool page_has_obj_cgroups(struct page *page)
-{
- return page->memcg_data & 0x1UL;
-}
-
int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s,
gfp_t gfp);
static inline void memcg_free_page_obj_cgroups(struct page *page)
{
- kfree(page_obj_cgroups(page));
+ kfree(page_objcgs(page));
page->memcg_data = 0;
}
@@ -322,7 +306,7 @@ static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
if (likely(p[i])) {
page = virt_to_head_page(p[i]);
- if (!page_has_obj_cgroups(page) &&
+ if (!page_objcgs(page) &&
memcg_alloc_page_obj_cgroups(page, s, flags)) {
obj_cgroup_uncharge(objcg, obj_full_size(s));
continue;
@@ -330,7 +314,7 @@ static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
off = obj_to_index(s, page, p[i]);
obj_cgroup_get(objcg);
- page_obj_cgroups(page)[off] = objcg;
+ page_objcgs(page)[off] = objcg;
mod_objcg_state(objcg, page_pgdat(page),
cache_vmstat_idx(s), obj_full_size(s));
} else {
@@ -344,6 +328,7 @@ static inline void memcg_slab_free_hook(struct kmem_cache *s_orig,
void **p, int objects)
{
struct kmem_cache *s;
+ struct obj_cgroup **objcgs;
struct obj_cgroup *objcg;
struct page *page;
unsigned int off;
@@ -357,7 +342,8 @@ static inline void memcg_slab_free_hook(struct kmem_cache *s_orig,
continue;
page = virt_to_head_page(p[i]);
- if (!page_has_obj_cgroups(page))
+ objcgs = page_objcgs(page);
+ if (!objcgs)
continue;
if (!s_orig)
@@ -366,11 +352,11 @@ static inline void memcg_slab_free_hook(struct kmem_cache *s_orig,
s = s_orig;
off = obj_to_index(s, page, p[i]);
- objcg = page_obj_cgroups(page)[off];
+ objcg = objcgs[off];
if (!objcg)
continue;
- page_obj_cgroups(page)[off] = NULL;
+ objcgs[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));
@@ -379,11 +365,6 @@ static inline void memcg_slab_free_hook(struct kmem_cache *s_orig,
}
#else /* CONFIG_MEMCG_KMEM */
-static inline bool page_has_obj_cgroups(struct page *page)
-{
- return false;
-}
-
static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr)
{
return NULL;