Messages in this thread Patch in this message | | | From | Vladimir Davydov <> | Subject | [PATCH -mm] memcg: zap memcg_can_account_kmem | Date | Wed, 24 Sep 2014 18:52:41 +0400 |
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memcg_can_account_kmem() returns true iff
!mem_cgroup_disabled() && !mem_cgroup_is_root(memcg) && memcg_kmem_is_active(memcg);
To begin with the !mem_cgroup_is_root(memcg) check is useless, because one can't enable kmem accounting for the root cgroup (mem_cgroup_write() returns EINVAL on an attempt to set the limit on the root cgroup).
Furthermore, the !mem_cgroup_disabled() check also seems to be redundant. The point is memcg_can_account_kmem() is called from three places: mem_cgroup_salbinfo_read(), __memcg_kmem_get_cache(), and __memcg_kmem_newpage_charge(). The latter two functions are only invoked if memcg_kmem_enabled() returns true, which implies that the memory cgroup subsystem is enabled. And mem_cgroup_slabinfo_read() shows the output of memory.kmem.slabinfo, which won't exist if the memory cgroup is completely disabled.
So let's substitute all the calls to memcg_can_account_kmem() with plain memcg_kmem_is_active(), and kill the former.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> --- mm/memcontrol.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 1ec22bf380d0..63d58d79470d 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2786,12 +2786,6 @@ static DEFINE_MUTEX(memcg_slab_mutex); static DEFINE_MUTEX(activate_kmem_mutex); -static inline bool memcg_can_account_kmem(struct mem_cgroup *memcg) -{ - return !mem_cgroup_disabled() && !mem_cgroup_is_root(memcg) && - memcg_kmem_is_active(memcg); -} - /* * This is a bit cumbersome, but it is rarely used and avoids a backpointer * in the memcg_cache_params struct. @@ -2811,7 +2805,7 @@ static int mem_cgroup_slabinfo_read(struct seq_file *m, void *v) struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); struct memcg_cache_params *params; - if (!memcg_can_account_kmem(memcg)) + if (!memcg_kmem_is_active(memcg)) return -EIO; print_slabinfo_header(m); @@ -3188,7 +3182,7 @@ struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep, rcu_read_lock(); memcg = mem_cgroup_from_task(rcu_dereference(current->mm->owner)); - if (!memcg_can_account_kmem(memcg)) + if (!memcg_kmem_is_active(memcg)) goto out; memcg_cachep = cache_from_memcg_idx(cachep, memcg_cache_id(memcg)); @@ -3273,7 +3267,7 @@ __memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **_memcg, int order) memcg = get_mem_cgroup_from_mm(current->mm); - if (!memcg_can_account_kmem(memcg)) { + if (!memcg_kmem_is_active(memcg)) { css_put(&memcg->css); return true; } -- 1.7.10.4
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