diff options
| author | Johannes Weiner <hannes@cmpxchg.org> | 2014-04-08 02:37:43 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-04-08 03:35:56 +0400 |
| commit | df381975463996178d685f6ef7d3555c5f887201 (patch) | |
| tree | 22fd4f923fc2cc1ed1d7c4aa94039452ce6123e5 /mm/memcontrol.c | |
| parent | 03583f1a631c0511dfd2f16e716d5b40f675de5a (diff) | |
| download | linux-df381975463996178d685f6ef7d3555c5f887201.tar.xz | |
memcg: get_mem_cgroup_from_mm()
Instead of returning NULL from try_get_mem_cgroup_from_mm() when the mm
owner is exiting, just return root_mem_cgroup. This makes sense for all
callsites and gets rid of some of them having to fallback manually.
[fengguang.wu@intel.com: fix warnings]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memcontrol.c')
| -rw-r--r-- | mm/memcontrol.c | 18 |
1 files changed, 4 insertions, 14 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index c3b674f9774f..87c3ec37dd26 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1071,7 +1071,7 @@ struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) return mem_cgroup_from_css(task_css(p, memory_cgrp_id)); } -struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) +static struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm) { struct mem_cgroup *memcg = NULL; @@ -1079,7 +1079,7 @@ struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm) do { memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); if (unlikely(!memcg)) - break; + memcg = root_mem_cgroup; } while (!css_tryget(&memcg->css)); rcu_read_unlock(); return memcg; @@ -1475,7 +1475,7 @@ bool task_in_mem_cgroup(struct task_struct *task, p = find_lock_task_mm(task); if (p) { - curr = try_get_mem_cgroup_from_mm(p->mm); + curr = get_mem_cgroup_from_mm(p->mm); task_unlock(p); } else { /* @@ -1489,8 +1489,6 @@ bool task_in_mem_cgroup(struct task_struct *task, css_get(&curr->css); rcu_read_unlock(); } - if (!curr) - return false; /* * We should check use_hierarchy of "memcg" not "curr". Because checking * use_hierarchy of "curr" here make this function true if hierarchy is @@ -3617,15 +3615,7 @@ __memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **_memcg, int order) if (!current->mm || current->memcg_kmem_skip_account) return true; - memcg = try_get_mem_cgroup_from_mm(current->mm); - - /* - * very rare case described in mem_cgroup_from_task. Unfortunately there - * isn't much we can do without complicating this too much, and it would - * be gfp-dependent anyway. Just let it go - */ - if (unlikely(!memcg)) - return true; + memcg = get_mem_cgroup_from_mm(current->mm); if (!memcg_can_account_kmem(memcg)) { css_put(&memcg->css); |