From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 14 Apr 2008 17:23:21 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [RFC][PATCH 3/3] account swapcache Message-Id: <20080414172321.b97c4eb9.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <48030FE9.1040401@mtf.biglobe.ne.jp> 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> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Daisuke Nishimura Cc: Daisuke Nishimura , "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: 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 -- 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