From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with SMTP id A007D6B0089 for ; Tue, 21 Apr 2009 23:18:03 -0400 (EDT) Received: from mt1.gw.fujitsu.co.jp ([10.0.50.74]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n3M3IHJI018928 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Wed, 22 Apr 2009 12:18:17 +0900 Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 3901145DE50 for ; Wed, 22 Apr 2009 12:18:17 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 02D0345DE4E for ; Wed, 22 Apr 2009 12:18:17 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id CEDF8E08005 for ; Wed, 22 Apr 2009 12:18:16 +0900 (JST) Received: from m107.s.css.fujitsu.com (m107.s.css.fujitsu.com [10.249.87.107]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 5994E1DB8040 for ; Wed, 22 Apr 2009 12:18:13 +0900 (JST) Date: Wed, 22 Apr 2009 12:16:41 +0900 From: KAMEZAWA Hiroyuki Subject: [PATCH] memcg: remove trylock_page_cgroup Message-Id: <20090422121641.eb84a07e.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20090422090218.6d451a08.kamezawa.hiroyu@jp.fujitsu.com> References: <20090416120316.GG7082@balbir.in.ibm.com> <20090417091459.dac2cc39.kamezawa.hiroyu@jp.fujitsu.com> <20090417014042.GB18558@balbir.in.ibm.com> <20090417110350.3144183d.kamezawa.hiroyu@jp.fujitsu.com> <20090417034539.GD18558@balbir.in.ibm.com> <20090417124951.a8472c86.kamezawa.hiroyu@jp.fujitsu.com> <20090417045623.GA3896@balbir.in.ibm.com> <20090417141726.a69ebdcc.kamezawa.hiroyu@jp.fujitsu.com> <20090417064726.GB3896@balbir.in.ibm.com> <20090417155608.eeed1f02.kamezawa.hiroyu@jp.fujitsu.com> <20090417141837.GD3896@balbir.in.ibm.com> <20090421132551.38e9960a.akpm@linux-foundation.org> <20090422090218.6d451a08.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: Andrew Morton , balbir@linux.vnet.ibm.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, "nishimura@mxp.nes.nec.co.jp" List-ID: How about this ? worth to be tested, I think. -Kame == From: KAMEZAWA Hiroyuki Before synchronized-LRU patch, mem cgroup had its own LRU lock. And there was a code which does # assume mz as per zone struct of memcg. spin_lock mz->lru_lock lock_page_cgroup(pc). and lock_page_cgroup(pc) spin_lock mz->lru_lock because we cannot locate "mz" until we see pc->page_cgroup, we used trylock(). But now, we don't have mz->lru_lock. All cgroup uses zone->lru_lock for handling list. Moreover, manipulation of LRU depends on global LRU now and we can isolate page from LRU by very generic way.(isolate_lru_page()). So, this kind of trylock is not necessary now. I thought I removed all trylock in synchronized-LRU patch but there is still one. This patch removes trylock used in memcontrol.c and its definition. If someone needs, he should add this again with enough reason. Signed-off-by: KAMEZAWA Hiroyuki --- include/linux/page_cgroup.h | 5 ----- mm/memcontrol.c | 3 +-- 2 files changed, 1 insertion(+), 7 deletions(-) Index: mmotm-2.6.30-Apr21/include/linux/page_cgroup.h =================================================================== --- mmotm-2.6.30-Apr21.orig/include/linux/page_cgroup.h +++ mmotm-2.6.30-Apr21/include/linux/page_cgroup.h @@ -61,11 +61,6 @@ static inline void lock_page_cgroup(stru bit_spin_lock(PCG_LOCK, &pc->flags); } -static inline int trylock_page_cgroup(struct page_cgroup *pc) -{ - return bit_spin_trylock(PCG_LOCK, &pc->flags); -} - static inline void unlock_page_cgroup(struct page_cgroup *pc) { bit_spin_unlock(PCG_LOCK, &pc->flags); Index: mmotm-2.6.30-Apr21/mm/memcontrol.c =================================================================== --- mmotm-2.6.30-Apr21.orig/mm/memcontrol.c +++ mmotm-2.6.30-Apr21/mm/memcontrol.c @@ -1148,8 +1148,7 @@ static int mem_cgroup_move_account(struc from_mz = mem_cgroup_zoneinfo(from, nid, zid); to_mz = mem_cgroup_zoneinfo(to, nid, zid); - if (!trylock_page_cgroup(pc)) - return ret; + lock_page_cgroup(pc); if (!PageCgroupUsed(pc)) goto out; -- 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/ . Don't email: email@kvack.org