diff options
| author | Qiang Huang | 2014-06-05 01:08:21 +0200 |
|---|---|---|
| committer | Linus Torvalds | 2014-06-05 01:54:05 +0200 |
| commit | bdcbb659fe630fc64f6604e99a180bb2ccc630c2 (patch) | |
| tree | 4a4a7ef641fcd4c704c47b55cf57fbbcb946d7d9 /mm/memcontrol.c | |
| parent | mm: update comment for DEFAULT_MAX_MAP_COUNT (diff) | |
| download | kernel-qcow2-linux-bdcbb659fe630fc64f6604e99a180bb2ccc630c2.tar.gz kernel-qcow2-linux-bdcbb659fe630fc64f6604e99a180bb2ccc630c2.tar.xz kernel-qcow2-linux-bdcbb659fe630fc64f6604e99a180bb2ccc630c2.zip | |
memcg: fold mem_cgroup_stolen
It is only used in __mem_cgroup_begin_update_page_stat(), the name is
confusing and 2 routines for one thing also confuse people, so fold this
function seems more clear.
[akpm@linux-foundation.org: fix typo, per Michal]
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
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 | 25 |
1 files changed, 7 insertions, 18 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 03d76628fd9d..4a9dfc83643d 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1594,23 +1594,12 @@ static void mem_cgroup_end_move(struct mem_cgroup *memcg) } /* - * 2 routines for checking "mem" is under move_account() or not. + * A routine for checking "mem" is under move_account() or not. * - * mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This - * is used for avoiding races in accounting. If true, - * pc->mem_cgroup may be overwritten. - * - * mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or - * under hierarchy of moving cgroups. This is for - * waiting at hith-memory prressure caused by "move". + * Checking a cgroup is mc.from or mc.to or under hierarchy of + * moving cgroups. This is for waiting at high-memory pressure + * caused by "move". */ - -static bool mem_cgroup_stolen(struct mem_cgroup *memcg) -{ - VM_BUG_ON(!rcu_read_lock_held()); - return atomic_read(&memcg->moving_account) > 0; -} - static bool mem_cgroup_under_move(struct mem_cgroup *memcg) { struct mem_cgroup *from; @@ -1653,7 +1642,6 @@ static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg) * Take this lock when * - a code tries to modify page's memcg while it's USED. * - a code tries to modify page state accounting in a memcg. - * see mem_cgroup_stolen(), too. */ static void move_lock_mem_cgroup(struct mem_cgroup *memcg, unsigned long *flags) @@ -2326,9 +2314,10 @@ again: * If this memory cgroup is not under account moving, we don't * need to take move_lock_mem_cgroup(). Because we already hold * rcu_read_lock(), any calls to move_account will be delayed until - * rcu_read_unlock() if mem_cgroup_stolen() == true. + * rcu_read_unlock(). */ - if (!mem_cgroup_stolen(memcg)) + VM_BUG_ON(!rcu_read_lock_held()); + if (atomic_read(&memcg->moving_account) <= 0) return; move_lock_mem_cgroup(memcg, flags); |