From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 18 Sep 2008 14:00:43 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [RFC][PATCH] Remove cgroup member from struct page (v3) Message-Id: <20080918140043.9ce73713.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <48D1D1C2.9060204@linux.vnet.ibm.com> References: <200809091500.10619.nickpiggin@yahoo.com.au> <20080909141244.721dfd39.kamezawa.hiroyu@jp.fujitsu.com> <30229398.1220963412858.kamezawa.hiroyu@jp.fujitsu.com> <20080910012048.GA32752@balbir.in.ibm.com> <1221085260.6781.69.camel@nimitz> <48C84C0A.30902@linux.vnet.ibm.com> <1221087408.6781.73.camel@nimitz> <20080911103500.d22d0ea1.kamezawa.hiroyu@jp.fujitsu.com> <48C878AD.4040404@linux.vnet.ibm.com> <20080911105638.1581db90.kamezawa.hiroyu@jp.fujitsu.com> <20080917232826.GA19256@balbir.in.ibm.com> <20080917184008.92b7fc4c.akpm@linux-foundation.org> <48D1D1C2.9060204@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: balbir@linux.vnet.ibm.com Cc: Andrew Morton , Dave Hansen , Nick Piggin , hugh@veritas.com, menage@google.com, xemul@openvz.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Wed, 17 Sep 2008 20:57:54 -0700 Balbir Singh wrote: > Andrew Morton wrote: > > someone somewhere decided that (Aa + Bb) / Cc < 1.0. What are the values > > of A, B and C and where did they come from? ;) > > > > (IOW, your changelog is in the category "sucky", along with 90% of the others) > > Yes, I agree, to be honest we discussed the reasons on the mailing list and > those should go to the changelog. I'll do that in the next version of the > patches. These are early RFC patches, but the changelog does suck. > IIRC, (Aa + Bb) / Cc < 1.0 discussion was following. Because we have to maintain pointer to page_cgroup in radix-tree (ZONE_NORMAL) 1. memory usage will increase when memory cgroup is enabled. The amount memory usage increase just depends on the height of radix-tree. 2. memory usage will decrease when memory cgroup is disabled. This saves 4bytes per 4096bytes. (on x86-32) Thanks, -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/ . Don't email: email@kvack.org