提交 2733c06a 编写于 作者: K KOSAKI Motohiro 提交者: Linus Torvalds

memcg: protect prev_priority

Currently, mem_cgroup doesn't have own lock and almost its member doesn't
need.  (e.g.  mem_cgroup->info is protected by zone lock, mem_cgroup->stat
is per cpu variable)

However, there is one explict exception.  mem_cgroup->prev_priorit need
lock, but doesn't protect.  Luckly, this is NOT bug because prev_priority
isn't used for current reclaim code.

However, we plan to use prev_priority future again.  Therefore, fixing is
better.

In addition, we plan to reuse this lock for another member.  Then
"reclaim_param_lock" name is better than "prev_priority_lock".
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
上级 e72e2bd6
...@@ -144,6 +144,11 @@ struct mem_cgroup { ...@@ -144,6 +144,11 @@ struct mem_cgroup {
*/ */
struct mem_cgroup_lru_info info; struct mem_cgroup_lru_info info;
/*
protect against reclaim related member.
*/
spinlock_t reclaim_param_lock;
int prev_priority; /* for recording reclaim priority */ int prev_priority; /* for recording reclaim priority */
/* /*
...@@ -400,18 +405,28 @@ int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem) ...@@ -400,18 +405,28 @@ int mem_cgroup_calc_mapped_ratio(struct mem_cgroup *mem)
*/ */
int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem) int mem_cgroup_get_reclaim_priority(struct mem_cgroup *mem)
{ {
return mem->prev_priority; int prev_priority;
spin_lock(&mem->reclaim_param_lock);
prev_priority = mem->prev_priority;
spin_unlock(&mem->reclaim_param_lock);
return prev_priority;
} }
void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority) void mem_cgroup_note_reclaim_priority(struct mem_cgroup *mem, int priority)
{ {
spin_lock(&mem->reclaim_param_lock);
if (priority < mem->prev_priority) if (priority < mem->prev_priority)
mem->prev_priority = priority; mem->prev_priority = priority;
spin_unlock(&mem->reclaim_param_lock);
} }
void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority) void mem_cgroup_record_reclaim_priority(struct mem_cgroup *mem, int priority)
{ {
spin_lock(&mem->reclaim_param_lock);
mem->prev_priority = priority; mem->prev_priority = priority;
spin_unlock(&mem->reclaim_param_lock);
} }
int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg, struct zone *zone) int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg, struct zone *zone)
...@@ -2076,6 +2091,7 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) ...@@ -2076,6 +2091,7 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
} }
mem_cgroup_set_inactive_ratio(mem); mem_cgroup_set_inactive_ratio(mem);
mem->last_scanned_child = NULL; mem->last_scanned_child = NULL;
spin_lock_init(&mem->reclaim_param_lock);
return &mem->css; return &mem->css;
free_out: free_out:
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册