From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with ESMTP id 16F188D0039 for ; Wed, 23 Feb 2011 13:19:27 -0500 (EST) Received: from d01relay03.pok.ibm.com (d01relay03.pok.ibm.com [9.56.227.235]) by e8.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id p1NE0mdD029838 for ; Wed, 23 Feb 2011 09:00:48 -0500 Received: from d01av01.pok.ibm.com (d01av01.pok.ibm.com [9.56.224.215]) by d01relay03.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p1NIJOmY331466 for ; Wed, 23 Feb 2011 13:19:24 -0500 Received: from d01av01.pok.ibm.com (loopback [127.0.0.1]) by d01av01.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p1NIJOtN001330 for ; Wed, 23 Feb 2011 13:19:24 -0500 Subject: Re: [RFC PATCH] page_cgroup: Reduce allocation overhead for page_cgroup array for CONFIG_SPARSEMEM From: Dave Hansen In-Reply-To: <20110223151047.GA7275@tiehlicka.suse.cz> References: <20110223151047.GA7275@tiehlicka.suse.cz> Content-Type: text/plain; charset="ANSI_X3.4-1968" Date: Wed, 23 Feb 2011 10:19:22 -0800 Message-ID: <1298485162.7236.4.camel@nimitz> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: linux-mm@kvack.org, KAMEZAWA Hiroyuki , linux-kernel@vger.kernel.org On Wed, 2011-02-23 at 16:10 +0100, Michal Hocko wrote: > We can reduce this internal fragmentation by splitting the single > page_cgroup array into more arrays where each one is well kmalloc > aligned. This patch implements this idea. How about using alloc_pages_exact()? These things aren't allocated often enough to really get most of the benefits of being in a slab. That'll at least get you down to a maximum of about PAGE_SIZE wasted. -- Dave -- 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