mm: memcontrol: zap memcg_kmem_online helper

As kmem accounting is now either enabled for all cgroups or disabled
system-wide, there's no point in having memcg_kmem_online() helper -
instead one can use memcg_kmem_enabled() and mem_cgroup_online(), as
shrink_slab() now does.

There are only two places left where this helper is used -
__memcg_kmem_charge() and memcg_create_kmem_cache().  The former can
only be called if memcg_kmem_enabled() returned true.  Since the cgroup
it operates on is online, mem_cgroup_is_root() check will be enough.

memcg_create_kmem_cache() can't use mem_cgroup_online() helper instead
of memcg_kmem_online(), because it relies on the fact that in
memcg_offline_kmem() memcg->kmem_state is changed before
memcg_deactivate_kmem_caches() is called, but there we can just
open-code the check.

Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Vladimir Davydov
2016-03-17 14:18:33 -07:00
committed by Linus Torvalds
parent 0fc9f58a90
commit b6ecd2dea4
3 changed files with 2 additions and 12 deletions

View File

@@ -795,11 +795,6 @@ static inline bool memcg_kmem_enabled(void)
return static_branch_unlikely(&memcg_kmem_enabled_key);
}
static inline bool memcg_kmem_online(struct mem_cgroup *memcg)
{
return memcg->kmem_state == KMEM_ONLINE;
}
/*
* In general, we'll do everything in our power to not incur in any overhead
* for non-memcg users for the kmem functions. Not even a function call, if we
@@ -909,11 +904,6 @@ static inline bool memcg_kmem_enabled(void)
return false;
}
static inline bool memcg_kmem_online(struct mem_cgroup *memcg)
{
return false;
}
static inline int memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
{
return 0;