Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757476AbZDXGZ2 (ORCPT ); Fri, 24 Apr 2009 02:25:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752654AbZDXGZM (ORCPT ); Fri, 24 Apr 2009 02:25:12 -0400 Received: from TYO202.gate.nec.co.jp ([202.32.8.206]:62034 "EHLO tyo202.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751902AbZDXGZK (ORCPT ); Fri, 24 Apr 2009 02:25:10 -0400 Date: Fri, 24 Apr 2009 15:21:03 +0900 From: Daisuke Nishimura To: KAMEZAWA Hiroyuki Cc: nishimura@mxp.nes.nec.co.jp, "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "balbir@linux.vnet.ibm.com" , "hugh@veritas.com" Subject: Re: [RFC][PATCH] fix swap entries is not reclaimed in proper way for mem+swap controller Message-Id: <20090424152103.a5ee8d13.nishimura@mxp.nes.nec.co.jp> In-Reply-To: <20090424133306.0d9fb2ce.kamezawa.hiroyu@jp.fujitsu.com> References: <20090421162121.1a1d15fe.kamezawa.hiroyu@jp.fujitsu.com> <20090422143833.2e11e10b.nishimura@mxp.nes.nec.co.jp> <20090424133306.0d9fb2ce.kamezawa.hiroyu@jp.fujitsu.com> Organization: NEC Soft, Ltd. X-Mailer: Sylpheed 2.6.0 (GTK+ 2.10.14; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1806 Lines: 46 On Fri, 24 Apr 2009 13:33:06 +0900, KAMEZAWA Hiroyuki wrote: > On Wed, 22 Apr 2009 14:38:33 +0900 > Daisuke Nishimura wrote: > > > > #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP > > > extern void mem_cgroup_uncharge_swap(swp_entry_t ent); > > > +extern void mem_cgroup_mark_swapcache_stale(struct page *page); > > > +extern void mem_cgroup_fixup_swapcache(struct page *page); > > > #else > > > static inline void mem_cgroup_uncharge_swap(swp_entry_t ent) > > > { > > > } > > > +static void mem_cgroup_check_mark_swapcache_stale(struct page *page) > > > +{ > > > +} > > > +static void mem_cgroup_fixup_swapcache(struct page *page) > > > +{ > > > +} > > > #endif > > > > > I think they should be defined in MEM_RES_CTLR case. > > Exhausting swap entries problem is not depend on MEM_RES_CTLR_SWAP. > > > Could you explain this more ? I can't understand. > STALE(!PageCgroupUsed) SwapCache *without owner process* can be created by the race between exit()..free_swap_and_cache() and read_swap_cache_async()(type-1) or between exit()..page_remove_rmap() and shrink_page_list()(type-2). (I don't think STALE SwapCache itself is problematic as long as there is an actual user of the SwapCache.) Those NOUSER STALE SwapCache are NOT depend on MEM_RES_CTLR_SWAP. If total_swap_size is small enough not to trigger global LRU scan, all swap space can be used up. I confirmed before that all swap space were used up(and caused oom) with mem.limit=32M/total_swap_size=50M. Thanks, Daisuke Nishimura. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/