From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yk0-f177.google.com (mail-yk0-f177.google.com [209.85.160.177]) by kanga.kvack.org (Postfix) with ESMTP id 492006B0253 for ; Fri, 28 Aug 2015 14:32:13 -0400 (EDT) Received: by ykek5 with SMTP id k5so10152421yke.3 for ; Fri, 28 Aug 2015 11:32:13 -0700 (PDT) Received: from mail-yk0-x232.google.com (mail-yk0-x232.google.com. [2607:f8b0:4002:c07::232]) by mx.google.com with ESMTPS id j137si4607903ywg.114.2015.08.28.11.32.11 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 28 Aug 2015 11:32:12 -0700 (PDT) Received: by ykek5 with SMTP id k5so10151867yke.3 for ; Fri, 28 Aug 2015 11:32:11 -0700 (PDT) Date: Fri, 28 Aug 2015 14:32:09 -0400 From: Tejun Heo Subject: Re: [PATCH 1/4] memcg: fix over-high reclaim amount Message-ID: <20150828183209.GA9423@mtj.duckdns.org> References: <1440775530-18630-1-git-send-email-tj@kernel.org> <1440775530-18630-2-git-send-email-tj@kernel.org> <20150828170612.GA21463@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150828170612.GA21463@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: hannes@cmpxchg.org, cgroups@vger.kernel.org, linux-mm@kvack.org, vdavydov@parallels.com, kernel-team@fb.com Hello, On Fri, Aug 28, 2015 at 07:06:13PM +0200, Michal Hocko wrote: > I do not think this a better behavior. If you have parallel charges to > the same memcg then you can easilly over-reclaim because everybody > will reclaim the maximum rather than its contribution. > > Sure we can fail to reclaim the target and slowly grow over high limit > but that is to be expected. This is not the max limit which cannot be > breached and external memory pressure/reclaim is there to mitigate that. Ah, I see, yeah, over-reclaim can happen. How about just wrapping the over-high reclaim with a per-memcg mutex? Do we gain anything by putting multiple tasks into the reclaim path? Thanks. -- tejun -- 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