From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with SMTP id 0413A6B00D4 for ; Mon, 27 Apr 2009 20:20:17 -0400 (EDT) Received: from m2.gw.fujitsu.co.jp ([10.0.50.72]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n3S0KYq9022004 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Tue, 28 Apr 2009 09:20:34 +0900 Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id A86C845DE62 for ; Tue, 28 Apr 2009 09:20:34 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (s2.gw.fujitsu.co.jp [10.0.50.92]) by m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 838EC45DE51 for ; Tue, 28 Apr 2009 09:20:34 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 667291DB803B for ; Tue, 28 Apr 2009 09:20:34 +0900 (JST) Received: from ml13.s.css.fujitsu.com (ml13.s.css.fujitsu.com [10.249.87.103]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 1AD081DB8038 for ; Tue, 28 Apr 2009 09:20:34 +0900 (JST) Date: Tue, 28 Apr 2009 09:19:02 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH] fix leak of swap accounting as stale swap cache under memcg Message-Id: <20090428091902.fc44efbc.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20090427210856.d5f4109e.d-nishimura@mtf.biglobe.ne.jp> References: <20090427181259.6efec90b.kamezawa.hiroyu@jp.fujitsu.com> <20090427210856.d5f4109e.d-nishimura@mtf.biglobe.ne.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: nishimura@mxp.nes.nec.co.jp Cc: Daisuke Nishimura , "linux-mm@kvack.org" , "balbir@linux.vnet.ibm.com" , "hugh@veritas.com" , "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" List-ID: On Mon, 27 Apr 2009 21:08:56 +0900 Daisuke Nishimura wrote: > > Index: mmotm-2.6.30-Apr24/mm/vmscan.c > > =================================================================== > > --- mmotm-2.6.30-Apr24.orig/mm/vmscan.c > > +++ mmotm-2.6.30-Apr24/mm/vmscan.c > > @@ -661,6 +661,9 @@ static unsigned long shrink_page_list(st > > if (PageAnon(page) && !PageSwapCache(page)) { > > if (!(sc->gfp_mask & __GFP_IO)) > > goto keep_locked; > > + /* avoid making more stale swap caches */ > > + if (memcg_stale_swap_congestion()) > > + goto keep_locked; > > if (!add_to_swap(page)) > > goto activate_locked; > > may_enter_fs = 1; > > > Well, as I mentioned before(http://marc.info/?l=linux-kernel&m=124066623510867&w=2), > this cannot avoid type-2(set !PageCgroupUsed by the owner process via > page_remove_rmap()->mem_cgroup_uncharge_page() before being added to swap cache). > If these swap caches go through shrink_page_list() without beeing freed > for some reason, these swap caches doesn't go back to memcg's LRU. > > Type-2 doesn't pressure memsw.usage, but you can see it by plotting > "grep SwapCached /proc/meminfo". > > And I don't think it's a good idea to add memcg_stale_swap_congestion() here. > This means less possibility to reclaim pages. > Hmm. maybe adding congestion_wait() ? > Do you dislike the patch I attached in the above mail ? > I doubt whether the patch covers all type-2 case. > If not, please merge it(I tested your prvious version with some fixes and > my patch, and it worked well). Or shall I send is as a separate patch > to fix type-2 after your patch(yours looks good to me for type-1)? > (to tell the truth, I want reuse memcg_free_unused_swapcache() in another patch) > > I'll consider again and post v3. But I'll go into a series of holidays, so, may not come back until May/6. Thanks, -Kame > Thanks, > Daisuke Nishimura. > -- 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