From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx207.postini.com [74.125.245.207]) by kanga.kvack.org (Postfix) with SMTP id F42256B00FC for ; Mon, 20 Feb 2012 12:23:49 -0500 (EST) Received: by mail-bk0-f41.google.com with SMTP id y12so6268158bkt.14 for ; Mon, 20 Feb 2012 09:23:49 -0800 (PST) Subject: [PATCH v2 19/22] mm: handle lruvec relock in memory controller From: Konstantin Khlebnikov Date: Mon, 20 Feb 2012 21:23:47 +0400 Message-ID: <20120220172347.22196.22182.stgit@zurg> In-Reply-To: <20120220171138.22196.65847.stgit@zurg> References: <20120220171138.22196.65847.stgit@zurg> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org, Andrew Morton , linux-kernel@vger.kernel.org Cc: Hugh Dickins , KAMEZAWA Hiroyuki Carefully relock lruvec lru lock at page memory cgroup change. * Stabilize PageLRU() sign with __wait_lruvec_unlock(old_lruvec) It must be called between each pc->mem_cgroup change and page putback into new lruvec, otherwise someone else can lock old lruvec and see PageLRU(), while page already moved into other lruvec. * In free_pn_rcu() wait for lruvec lock release. Locking primitives keep lruvec pointer after successful lock held. Signed-off-by: Konstantin Khlebnikov --- mm/memcontrol.c | 36 ++++++++++++++++++++++++++++-------- 1 files changed, 28 insertions(+), 8 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 40e1a66..69763da 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2368,6 +2368,7 @@ static int mem_cgroup_move_account(struct page *page, unsigned long flags; int ret; bool anon = PageAnon(page); + struct lruvec *old_lruvec; VM_BUG_ON(from == to); VM_BUG_ON(PageLRU(page)); @@ -2397,12 +2398,24 @@ static int mem_cgroup_move_account(struct page *page, preempt_enable(); } mem_cgroup_charge_statistics(from, anon, -nr_pages); + + /* charge keep old lruvec alive */ + old_lruvec = page_lruvec(page); + + /* caller should have done css_get */ + pc->mem_cgroup = to; + + /* + * Stabilize PageLRU() sing for old_lruvec lock holder. + * Do not putback page while someone hold old_lruvec lock, + * otherwise it can think it catched page in old_lruvec lru. + */ + __wait_lruvec_unlock(old_lruvec); + if (uncharge) /* This is not "cancel", but cancel_charge does all we need. */ __mem_cgroup_cancel_charge(from, nr_pages); - /* caller should have done css_get */ - pc->mem_cgroup = to; mem_cgroup_charge_statistics(to, anon, nr_pages); /* * We charges against "to" which may not have any tasks. Then, "to" @@ -2528,7 +2541,6 @@ __mem_cgroup_commit_charge_lrucare(struct page *page, struct mem_cgroup *memcg, enum charge_type ctype) { struct page_cgroup *pc = lookup_page_cgroup(page); - struct zone *zone = page_zone(page); struct lruvec *lruvec; unsigned long flags; bool removed = false; @@ -2538,20 +2550,19 @@ __mem_cgroup_commit_charge_lrucare(struct page *page, struct mem_cgroup *memcg, * is already on LRU. It means the page may on some other page_cgroup's * LRU. Take care of it. */ - spin_lock_irqsave(&zone->lru_lock, flags); + lruvec = lock_page_lruvec(page, &flags); if (PageLRU(page)) { - lruvec = page_lruvec(page); del_page_from_lru_list(lruvec, page, page_lru(page)); ClearPageLRU(page); removed = true; } __mem_cgroup_commit_charge(memcg, page, 1, pc, ctype); if (removed) { - lruvec = page_lruvec(page); + lruvec = __relock_page_lruvec(lruvec, page); add_page_to_lru_list(lruvec, page, page_lru(page)); SetPageLRU(page); } - spin_unlock_irqrestore(&zone->lru_lock, flags); + unlock_lruvec(lruvec, &flags); } int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, @@ -4648,7 +4659,16 @@ static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) static void free_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node) { - kfree(memcg->info.nodeinfo[node]); + struct mem_cgroup_per_node *pn = memcg->info.nodeinfo[node]; + int zone; + + if (!pn) + return; + + for (zone = 0; zone < MAX_NR_ZONES; zone++) + wait_lruvec_unlock(&pn->zoneinfo[zone].lruvec); + + kfree(pn); } static struct mem_cgroup *mem_cgroup_alloc(void) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org