From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta12.messagelabs.com (mail6.bemta12.messagelabs.com [216.82.250.247]) by kanga.kvack.org (Postfix) with ESMTP id F276B6B004A for ; Thu, 2 Jun 2011 19:15:43 -0400 (EDT) Received: by bwz17 with SMTP id 17so2146283bwz.14 for ; Thu, 02 Jun 2011 16:15:39 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20110602221906.GA4554@cmpxchg.org> References: <1306909519-7286-1-git-send-email-hannes@cmpxchg.org> <1306909519-7286-8-git-send-email-hannes@cmpxchg.org> <20110602221906.GA4554@cmpxchg.org> Date: Fri, 3 Jun 2011 08:15:39 +0900 Message-ID: Subject: Re: [patch 7/8] vmscan: memcg-aware unevictable page rescue scanner From: Hiroyuki Kamezawa Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner Cc: Ying Han , KAMEZAWA Hiroyuki , Daisuke Nishimura , Balbir Singh , Michal Hocko , Andrew Morton , Rik van Riel , Minchan Kim , KOSAKI Motohiro , Mel Gorman , Greg Thelen , Michel Lespinasse , "linux-mm@kvack.org" , linux-kernel 2011年6月3日金曜日 Johannes Weiner hannes@cmpxchg.org: > On Fri, Jun 03, 2011 at 07:01:34AM +0900, Hiroyuki Kamezawa wrote: >> 2011/6/3 Ying Han : >> > On Thu, Jun 2, 2011 at 6:27 AM, Hiroyuki Kamezawa >> > wrote: >> >> 2011/6/1 Johannes Weiner : >> >>> Once the per-memcg lru lists are exclusive, the unevictable page >> >>> rescue scanner can no longer work on the global zone lru lists. >> >>> >> >>> This converts it to go through all memcgs and scan their respective >> >>> unevictable lists instead. >> >>> >> >>> Signed-off-by: Johannes Weiner >> >> >> >> Hm, isn't it better to have only one GLOBAL LRU for unevictable pages ? >> >> memcg only needs counter for unevictable pages and LRU is not necessary >> >> to be per memcg because we don't reclaim it... >> > >> > Hmm. Are we suggesting to keep one un-evictable LRU list for all >> > memcgs? So we will have >> > exclusive lru only for file and anon. If so, we are not done to make >> > all the lru list being exclusive >> > which is critical later to improve the zone->lru_lock contention >> > across the memcgs >> > >> considering lrulock, yes, maybe you're right. > > That's one of the complications. > >> > Sorry If i misinterpret the suggestion here >> > >> >> My concern is I don't know for what purpose this function is used .. > > I am not sure how it's supposed to be used, either. But it's > documented to be a 'really big hammer' and it's kicked off from > userspace. So I suppose having the thing go through all memcgs bears > a low risk of being a problem. My suggestion is we go that way until > someone complains. Ok. Please go with memcg local unevictable lru. -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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org