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From: Johannes Weiner <hannes@cmpxchg.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>,
Balbir Singh <balbir@linux.vnet.ibm.com>, <linux-mm@kvack.org>,
<linux-kernel@vger.kernel.org>
Subject: [patch 3/5] memcg: fold __mem_cgroup_move_account into caller
Date: Thu, 3 Feb 2011 15:26:04 +0100 [thread overview]
Message-ID: <1296743166-9412-4-git-send-email-hannes@cmpxchg.org> (raw)
In-Reply-To: <1296743166-9412-1-git-send-email-hannes@cmpxchg.org>
It is one logical function, no need to have it split up.
Also, get rid of some checks from the inner function that ensured the
sanity of the outer function.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
---
include/linux/page_cgroup.h | 5 ---
mm/memcontrol.c | 66 +++++++++++++++++++------------------------
2 files changed, 29 insertions(+), 42 deletions(-)
diff --git a/include/linux/page_cgroup.h b/include/linux/page_cgroup.h
index 363bbc8..6b63679 100644
--- a/include/linux/page_cgroup.h
+++ b/include/linux/page_cgroup.h
@@ -99,11 +99,6 @@ static inline void unlock_page_cgroup(struct page_cgroup *pc)
bit_spin_unlock(PCG_LOCK, &pc->flags);
}
-static inline int page_is_cgroup_locked(struct page_cgroup *pc)
-{
- return bit_spin_is_locked(PCG_LOCK, &pc->flags);
-}
-
static inline void move_lock_page_cgroup(struct page_cgroup *pc,
unsigned long *flags)
{
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 77a3f87..5eb0dc2 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2174,33 +2174,49 @@ void mem_cgroup_split_huge_fixup(struct page *head, struct page *tail)
#endif
/**
- * __mem_cgroup_move_account - move account of the page
+ * mem_cgroup_move_account - move account of the page
* @pc: page_cgroup of the page.
* @from: mem_cgroup which the page is moved from.
* @to: mem_cgroup which the page is moved to. @from != @to.
* @uncharge: whether we should call uncharge and css_put against @from.
+ * @charge_size: number of bytes to charge (regular or huge page)
*
* The caller must confirm following.
* - page is not on LRU (isolate_page() is useful.)
- * - the pc is locked, used, and ->mem_cgroup points to @from.
+ * - compound_lock is held when charge_size > PAGE_SIZE
*
* This function doesn't do "charge" nor css_get to new cgroup. It should be
* done by a caller(__mem_cgroup_try_charge would be usefull). If @uncharge is
* true, this function does "uncharge" from old cgroup, but it doesn't if
* @uncharge is false, so a caller should do "uncharge".
*/
-
-static void __mem_cgroup_move_account(struct page_cgroup *pc,
- struct mem_cgroup *from, struct mem_cgroup *to, bool uncharge,
- int charge_size)
+static int mem_cgroup_move_account(struct page_cgroup *pc,
+ struct mem_cgroup *from, struct mem_cgroup *to,
+ bool uncharge, int charge_size)
{
int nr_pages = charge_size >> PAGE_SHIFT;
+ unsigned long flags;
+ int ret;
VM_BUG_ON(from == to);
VM_BUG_ON(PageLRU(pc->page));
- VM_BUG_ON(!page_is_cgroup_locked(pc));
- VM_BUG_ON(!PageCgroupUsed(pc));
- VM_BUG_ON(pc->mem_cgroup != from);
+ /*
+ * The page is isolated from LRU. So, collapse function
+ * will not handle this page. But page splitting can happen.
+ * Do this check under compound_page_lock(). The caller should
+ * hold it.
+ */
+ ret = -EBUSY;
+ if (charge_size > PAGE_SIZE && !PageTransHuge(pc->page))
+ goto out;
+
+ lock_page_cgroup(pc);
+
+ ret = -EINVAL;
+ if (!PageCgroupUsed(pc) || pc->mem_cgroup != from)
+ goto unlock;
+
+ move_lock_page_cgroup(pc, &flags);
if (PageCgroupFileMapped(pc)) {
/* Update mapped_file data for mem_cgroup */
@@ -2224,40 +2240,16 @@ static void __mem_cgroup_move_account(struct page_cgroup *pc,
* garanteed that "to" is never removed. So, we don't check rmdir
* status here.
*/
-}
-
-/*
- * check whether the @pc is valid for moving account and call
- * __mem_cgroup_move_account()
- */
-static int mem_cgroup_move_account(struct page_cgroup *pc,
- struct mem_cgroup *from, struct mem_cgroup *to,
- bool uncharge, int charge_size)
-{
- int ret = -EINVAL;
- unsigned long flags;
- /*
- * The page is isolated from LRU. So, collapse function
- * will not handle this page. But page splitting can happen.
- * Do this check under compound_page_lock(). The caller should
- * hold it.
- */
- if ((charge_size > PAGE_SIZE) && !PageTransHuge(pc->page))
- return -EBUSY;
-
- lock_page_cgroup(pc);
- if (PageCgroupUsed(pc) && pc->mem_cgroup == from) {
- move_lock_page_cgroup(pc, &flags);
- __mem_cgroup_move_account(pc, from, to, uncharge, charge_size);
- move_unlock_page_cgroup(pc, &flags);
- ret = 0;
- }
+ move_unlock_page_cgroup(pc, &flags);
+ ret = 0;
+unlock:
unlock_page_cgroup(pc);
/*
* check events
*/
memcg_check_events(to, pc->page);
memcg_check_events(from, pc->page);
+out:
return ret;
}
--
1.7.4
next prev parent reply other threads:[~2011-02-03 14:27 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-03 14:26 memcg: save 20% of per-page memcg memory overhead Johannes Weiner
2011-02-03 14:26 ` [patch 1/5] memcg: no uncharged pages reach page_cgroup_zoneinfo Johannes Weiner
2011-02-04 0:01 ` KAMEZAWA Hiroyuki
2011-02-04 9:26 ` Johannes Weiner
2011-02-04 9:23 ` KAMEZAWA Hiroyuki
2011-02-04 4:16 ` Balbir Singh
2011-02-03 14:26 ` [patch 2/5] memcg: change page_cgroup_zoneinfo signature Johannes Weiner
2011-02-04 0:03 ` KAMEZAWA Hiroyuki
2011-02-03 14:26 ` Johannes Weiner [this message]
2011-02-04 0:07 ` [patch 3/5] memcg: fold __mem_cgroup_move_account into caller KAMEZAWA Hiroyuki
2011-02-04 0:53 ` Daisuke Nishimura
2011-02-03 14:26 ` [patch 4/5] memcg: condense page_cgroup-to-page lookup points Johannes Weiner
2011-02-04 0:10 ` KAMEZAWA Hiroyuki
2011-02-03 14:26 ` [patch 5/5] memcg: remove direct page_cgroup-to-page pointer Johannes Weiner
2011-02-04 0:19 ` KAMEZAWA Hiroyuki
2011-02-04 9:51 ` Johannes Weiner
2011-02-03 15:02 ` memcg: save 20% of per-page memcg memory overhead Balbir Singh
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