From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id 220618D0039 for ; Fri, 28 Jan 2011 00:04:48 -0500 (EST) Received: from m4.gw.fujitsu.co.jp (unknown [10.0.50.74]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id B3C633EE0B3 for ; Fri, 28 Jan 2011 14:04:45 +0900 (JST) Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 98CF445DE52 for ; Fri, 28 Jan 2011 14:04:45 +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 76E2A45DE4F for ; Fri, 28 Jan 2011 14:04:45 +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 677281DB8040 for ; Fri, 28 Jan 2011 14:04:45 +0900 (JST) Received: from ml13.s.css.fujitsu.com (ml13.s.css.fujitsu.com [10.249.87.103]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 1F4EF1DB803B for ; Fri, 28 Jan 2011 14:04:45 +0900 (JST) Date: Fri, 28 Jan 2011 13:58:39 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [BUGFIX][PATCH 1/4] memcg: fix limit estimation at reclaim for hugepage Message-Id: <20110128135839.d53422e8.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20110128134019.27abcfe2.nishimura@mxp.nes.nec.co.jp> References: <20110128122229.6a4c74a2.kamezawa.hiroyu@jp.fujitsu.com> <20110128122449.e4bb0e5f.kamezawa.hiroyu@jp.fujitsu.com> <20110128134019.27abcfe2.nishimura@mxp.nes.nec.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Daisuke Nishimura Cc: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "hannes@cmpxchg.org" , "balbir@linux.vnet.ibm.com" List-ID: How about this ? == From: KAMEZAWA Hiroyuki Current memory cgroup's code tends to assume page_size == PAGE_SIZE and arrangement for THP is not enough yet. This is one of fixes for supporing THP. This adds mem_cgroup_check_margin() and checks whether there are required amount of free resource after memory reclaim. By this, THP page allocation can know whether it really succeeded or not and avoid infinite-loop and hangup. Total fixes for do_charge()/reclaim memory will follow this patch. Changelog v1->v2: - style fix. Signed-off-by: KAMEZAWA Hiroyuki --- include/linux/res_counter.h | 11 +++++++++++ mm/memcontrol.c | 22 +++++++++++++++++++++- 2 files changed, 32 insertions(+), 1 deletion(-) Index: mmotm-0125/include/linux/res_counter.h =================================================================== --- mmotm-0125.orig/include/linux/res_counter.h +++ mmotm-0125/include/linux/res_counter.h @@ -182,6 +182,17 @@ static inline bool res_counter_check_und return ret; } +static inline s64 res_counter_check_margin(struct res_counter *cnt) +{ + s64 ret; + unsigned long flags; + + spin_lock_irqsave(&cnt->lock, flags); + ret = cnt->limit - cnt->usage; + spin_unlock_irqrestore(&cnt->lock, flags); + return ret; +} + static inline bool res_counter_check_under_soft_limit(struct res_counter *cnt) { bool ret; Index: mmotm-0125/mm/memcontrol.c =================================================================== --- mmotm-0125.orig/mm/memcontrol.c +++ mmotm-0125/mm/memcontrol.c @@ -1111,6 +1111,19 @@ static bool mem_cgroup_check_under_limit return false; } +static s64 mem_cgroup_check_margin(struct mem_cgroup *mem) +{ + s64 mem_margin = res_counter_check_margin(&mem->res); + s64 memsw_margin; + + if (do_swap_account) + memsw_margin = res_counter_check_margin(&mem->memsw); + else + memsw_margin = RESOURCE_MAX; + + return min(mem_margin, memsw_margin); +} + static unsigned int get_swappiness(struct mem_cgroup *memcg) { struct cgroup *cgrp = memcg->css.cgroup; @@ -1853,7 +1866,14 @@ static int __mem_cgroup_do_charge(struct * Check the limit again to see if the reclaim reduced the * current usage of the cgroup before giving up */ - if (ret || mem_cgroup_check_under_limit(mem_over_limit)) + if (mem_cgroup_check_margin(mem_over_limit) >= csize) + return CHARGE_RETRY; + + /* + * If the charge size is a PAGE_SIZE, it's not hopeless while + * we can reclaim a page. + */ + if (csize == PAGE_SIZE && ret) return CHARGE_RETRY; /* -- 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 policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org