From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <48031775.10008@mtf.biglobe.ne.jp> Date: Mon, 14 Apr 2008 17:36:05 +0900 From: Daisuke Nishimura Reply-To: Daisuke Nishimura MIME-Version: 1.0 Subject: Re: [RFC][PATCH 3/3] account swapcache References: <20080408190734.70ab55b0.kamezawa.hiroyu@jp.fujitsu.com> <20080408191311.73b167bb.kamezawa.hiroyu@jp.fujitsu.com> <47FF57A7.5000704@mxp.nes.nec.co.jp> <20080414094709.fb9c3745.kamezawa.hiroyu@jp.fujitsu.com> <48030FE9.1040401@mtf.biglobe.ne.jp> <20080414172321.b97c4eb9.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20080414172321.b97c4eb9.kamezawa.hiroyu@jp.fujitsu.com> Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "balbir@linux.vnet.ibm.com" , "xemul@openvz.org" , "yamamoto@valinux.co.jp" , lizf@cn.fujitsu.com, Hugh Dickins , "IKEDA, Munehiro" List-ID: KAMEZAWA Hiroyuki wrote: > On Mon, 14 Apr 2008 17:03:53 +0900 > Daisuke Nishimura wrote: > >> I was thinking the case below. >> Assume some anonymous pages(mapped, referenced, !SwapCache) >> are being reclaimed. >> > > Numbering for below. > > (1) > shrink_page_list() > (2)> -> add_to_swap() <- makes the page dirty. > (3)> -> try_to_unmap() <- uncharged from memcg and removed from mz->lru. > (4)> -> PageDirty() == true > (5)> sc->order <= PAGE_ALLOC_COSTLY_ORDER && referenced > (6)> goto keep_locked > (7)> -> unlocks the page and will work on other pages on page_list. >> And, if on other CPU the process that owns those pages is exiting >> at the timing of my example above, those pages remain only on >> global lru, and are never charged(mapped) because the process exits. >> >> I said "never" because once they are removed from mz->lru, >> mem_cgroup_isolate_pages() doesn't select those pages >> unless they are charged(mapped) again. >> > I'm sorry if I don't catch your points. > > Because of (1), it's marked as SwapCache. > At (2) , page is not removed from mz->lru because it's SwapCache. (see my patch) > page is still on mz->lru after (7). > > After a process exits, this page will be reclaimed when page-recalim for > page_cgroup find this. > > Thanks, > -Kame > I was saying the case when swapcaches are not charged. I showed one of the problems if they are not charged. Sorry for confusing you. I agree that your patch handles this case :-) 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