From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx194.postini.com [74.125.245.194]) by kanga.kvack.org (Postfix) with SMTP id B65796B004D for ; Tue, 20 Dec 2011 20:14:56 -0500 (EST) Message-ID: <4EF132EA.7000300@am.sony.com> Date: Tue, 20 Dec 2011 17:14:18 -0800 From: Frank Rowand Reply-To: MIME-Version: 1.0 Subject: Re: Android low memory killer vs. memory pressure notifications References: <20111219025328.GA26249@oksana.dev.rtsoft.ru> <20111219121255.GA2086@tiehlicka.suse.cz> <20111220145654.GA26881@oksana.dev.rtsoft.ru> <20111221002853.GA11504@oksana.dev.rtsoft.ru> In-Reply-To: <20111221002853.GA11504@oksana.dev.rtsoft.ru> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Anton Vorontsov Cc: David Rientjes , KOSAKI Motohiro , Michal Hocko , =?UTF-8?B?QXJ2ZSBIasO4bm5ldsOlZw==?= , Rik van Riel , Pavel Machek , Greg Kroah-Hartman , Andrew Morton , John Stultz , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , Johannes Weiner , KAMEZAWA Hiroyuki , Alan Cox , tbird20d@gmail.com On 12/20/11 16:28, Anton Vorontsov wrote: > On Tue, Dec 20, 2011 at 01:36:00PM -0800, David Rientjes wrote: >> On Tue, 20 Dec 2011, Anton Vorontsov wrote: >> >>> Hm, assuming that metadata is no longer an issue, why do you think avoiding >>> cgroups would be a good idea? >>> >> >> It's helpful for certain end users, particularly those in the embedded >> world, to be able to disable as many config options as possible to reduce >> the size of kernel image as much as possible, so they'll want a minimal >> amount of kernel functionality that allows such notifications. Keep in >> mind that CONFIG_CGROUP_MEM_RES_CTLR is not enabled by default because of >> this (enabling it, CONFIG_RESOURCE_COUNTERS, and CONFIG_CGROUPS increases >> the size of the kernel text by ~1%), > > So for 2MB kernel that's about 20KB of an additional text... This seems > affordable, especially as a trade-off for the things that cgroups may > provide. A comment from http://lkml.indiana.edu/hypermail/linux/kernel/1102.1/00412.html: "I care about 5K. (But honestly, I don't actively hunt stuff less than 10K in size, because there's too many of them to chase, currently)." > > The fact is, for desktop and server Linux, cgroups slowly becomes a > mandatory thing. And the reason for this is that cgroups mechanism > provides some very useful features (in an extensible way, like plugins), > i.e. a way to manage and track processes and its resources -- which is the > main purpose of cgroups. And for embedded and for real-time, some of us do not want cgroups to be a mandatory thing. We want it to remain configurable. My personal interest is in keeping the latency of certain critical paths (especially in the scheduler) short and consistent. -Frank -- 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