Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750934Ab1C2EDx (ORCPT ); Tue, 29 Mar 2011 00:03:53 -0400 Received: from smtp-out.google.com ([216.239.44.51]:43897 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750704Ab1C2EDw (ORCPT ); Tue, 29 Mar 2011 00:03:52 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=google.com; s=beta; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=vwFCgAsxy5ngvLT9hwrciRRoY4HD8k5VlTrHIGWzCnsEvtVB7IjXy7l2yIfTgCuHnl ruleWzFKsJx2O+hHIU8A== MIME-Version: 1.0 In-Reply-To: <20110329114555.cb5d5c51.kamezawa.hiroyu@jp.fujitsu.com> References: <20110328093957.089007035@suse.cz> <20110329091254.20c7cfcb.kamezawa.hiroyu@jp.fujitsu.com> <20110329094756.49af153d.kamezawa.hiroyu@jp.fujitsu.com> <20110329114555.cb5d5c51.kamezawa.hiroyu@jp.fujitsu.com> Date: Mon, 28 Mar 2011 21:03:46 -0700 Message-ID: Subject: Re: [RFC 0/3] Implementation of cgroup isolation From: Ying Han To: KAMEZAWA Hiroyuki Cc: Michal Hocko , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Hugh Dickins , Suleiman Souhlal Content-Type: text/plain; charset=ISO-8859-1 X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2661 Lines: 82 On Mon, Mar 28, 2011 at 7:45 PM, KAMEZAWA Hiroyuki wrote: > On Mon, 28 Mar 2011 19:46:41 -0700 > Ying Han wrote: > >> On Mon, Mar 28, 2011 at 5:47 PM, KAMEZAWA Hiroyuki >> wrote: > >> > >> >> By saying that, memcg simplified the memory accounting per-cgroup but >> >> the memory isolation is broken. This is one of examples where pages >> >> are shared between global LRU and per-memcg LRU. It is easy to get >> >> cgroup-A's page evicted by adding memory pressure to cgroup-B. >> >> >> > If you overcommit....Right ? >> >> yes, we want to support the configuration of over-committing the >> machine w/ limit_in_bytes. >> > > Then, soft_limit is a feature for fixing the problem. If you have problem > with soft_limit, let's fix it. The current implementation of soft_limit works as best-effort and some improvement are needed. Without distracting much from this thread, simply saying it is not optimized on which cgroup to pick from the per-zone RB-tree. > > >> > >> > >> >> The approach we are thinking to make the page->lru exclusive solve the >> >> problem. and also we should be able to break the zone->lru_lock >> >> sharing. >> >> >> > Is zone->lru_lock is a problem even with the help of pagevecs ? >> >> > If LRU management guys acks you to isolate LRUs and to make kswapd etc.. >> > more complex, okay, we'll go that way. >> >> I would assume the change only apply to memcg users , otherwise >> everything is leaving in the global LRU list. >> >> This will _change_ the whole memcg design and concepts Maybe memcg >> should have some kind of balloon driver to >> > work happy with isolated lru. >> >> We have soft_limit hierarchical reclaim for system memory pressure, >> and also we will add per-memcg background reclaim. Both of them do >> targeting reclaim on per-memcg LRUs, and where is the balloon driver >> needed? >> > > If soft_limit is _not_ enough. And I think you background reclaim should > be work with soft_limit and be triggered by global memory pressure. This is something i can think about. Also i think we agree that we should have efficient target reclaim so the global LRU scanning should be eliminated. > > As wrote in other mail, it's not called via direct reclaim. > Maybe its the 1st point to be shooted rather than trying big change. Agree on this. --Ying > > > > > Thanks, > -Kame > > -- 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/