From mboxrd@z Thu Jan 1 00:00:00 1970 From: Glauber Costa Subject: Re: [PATCH] memcg: implement boost mode Date: Mon, 1 Apr 2013 13:30:22 +0400 Message-ID: <515953AE.3000403@parallels.com> References: <1364801670-10241-1-git-send-email-glommer@parallels.com> <51595311.7070509@jp.fujitsu.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <51595311.7070509-+CUm20s59erQFUHtdCDX3A@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Kamezawa Hiroyuki Cc: linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, Michal Hocko , Johannes Weiner , Andrew Morton , cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Tejun Heo On 04/01/2013 01:27 PM, Kamezawa Hiroyuki wrote: > (2013/04/01 16:34), Glauber Costa wrote: >> There are scenarios in which we would like our programs to run faster. >> It is a hassle, when they are contained in memcg, that some of its >> allocations will fail and start triggering reclaim. This is not good >> for the program, that will now be slower. >> >> This patch implements boost mode for memcg. It exposes a u64 file >> "memcg boost". Every time you write anything to it, it will reduce the >> counters by ~20 %. Note that we don't want to actually reclaim pages, >> which would defeat the very goal of boost mode. We just make the >> res_counters able to accomodate more. >> >> This file is also available in the root cgroup. But with a slightly >> different effect. Writing to it will make more memory physically >> available so our programs can profit. >> >> Please ack and apply. >> > Nack. > >> Signed-off-by: Glauber Costa > > Please update limit temporary. If you need call-shrink-explicitly-by-user, > I think you can add it. > I don't want to shrink memory because that will make applications slower. I want them to be faster, so they need to have more memory. There is solid research backing up my approach: http://www.dilbert.com/fast/2008-05-08/