memcg: remove redundant code
- try_get_mem_cgroup_from_mm() calls rcu_read_lock/unlock by itself, so we
don't have to call them in task_in_mem_cgroup().
- *mz is not used in __mem_cgroup_uncharge_common().
- we don't have to call lookup_page_cgroup() in mem_cgroup_end_migration()
after we've cleared PCG_MIGRATION of @oldpage.
- remove empty comment.
- remove redundant empty line in mem_cgroup_cache_charge().
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 27981e7..79a53f0 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -840,9 +840,7 @@
struct mem_cgroup *curr = NULL;
task_lock(task);
- rcu_read_lock();
curr = try_get_mem_cgroup_from_mm(task->mm);
- rcu_read_unlock();
task_unlock(task);
if (!curr)
return 0;
@@ -2092,7 +2090,6 @@
if (!(gfp_mask & __GFP_WAIT)) {
struct page_cgroup *pc;
-
pc = lookup_page_cgroup(page);
if (!pc)
return 0;
@@ -2286,7 +2283,6 @@
{
struct page_cgroup *pc;
struct mem_cgroup *mem = NULL;
- struct mem_cgroup_per_zone *mz;
if (mem_cgroup_disabled())
return NULL;
@@ -2340,7 +2336,6 @@
* special functions.
*/
- mz = page_cgroup_zoneinfo(pc);
unlock_page_cgroup(pc);
memcg_check_events(mem, page);
@@ -2652,11 +2647,8 @@
ClearPageCgroupMigration(pc);
unlock_page_cgroup(pc);
- if (unused != oldpage)
- pc = lookup_page_cgroup(unused);
__mem_cgroup_uncharge_common(unused, MEM_CGROUP_CHARGE_TYPE_FORCE);
- pc = lookup_page_cgroup(used);
/*
* If a page is a file cache, radix-tree replacement is very atomic
* and we can skip this check. When it was an Anon page, its mapcount
@@ -3800,8 +3792,6 @@
return 0;
}
-/*
- */
static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
struct cftype *cft, u64 val)
{