Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751379Ab0KHFWJ (ORCPT ); Mon, 8 Nov 2010 00:22:09 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:54060 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1749667Ab0KHFWI (ORCPT ); Mon, 8 Nov 2010 00:22:08 -0500 Message-ID: <4CD78946.5060405@cn.fujitsu.com> Date: Mon, 08 Nov 2010 13:23:18 +0800 From: Li Zefan User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1b3pre) Gecko/20090513 Fedora/3.0-2.3.beta2.fc11 Thunderbird/3.0b2 MIME-Version: 1.0 To: Paul Menage CC: "akpm >> Andrew Morton" , Stephane Eranian , LKML , containers@lists.linux-foundation.org Subject: Re: [PATCH 1/7] cgroups: Shrink struct cgroup_subsys References: <4CC146A4.9090505@cn.fujitsu.com> <4CC146BA.7080009@cn.fujitsu.com> In-Reply-To: X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2010-11-08 13:22:36, Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2010-11-08 13:22:36, Serialize complete at 2010-11-08 13:22:36 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1672 Lines: 65 (Sorry for the delayed reply) Paul Menage wrote: > On Fri, Oct 22, 2010 at 1:09 AM, Li Zefan wrote: >> On x86_32, sizeof(struct cgroup_subsys) shrinks from 276 bytes >> to 264. >> >> Signed-off-by: Li Zefan > > Acked-by: Paul Menage > > Maybe use "bool" here? > Do you mean: bool active; bool disabled; ... ? With alignment 5-8 bool values == 8 bytes in 64-bit machine, compared to 4 bytes with the approach this patch takes. > Paul > >> --- >> include/linux/cgroup.h | 10 ++++++---- >> 1 files changed, 6 insertions(+), 4 deletions(-) >> >> diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h >> index ed4ba11..e23ded6 100644 >> --- a/include/linux/cgroup.h >> +++ b/include/linux/cgroup.h >> @@ -481,14 +481,16 @@ struct cgroup_subsys { >> void (*bind)(struct cgroup_subsys *ss, struct cgroup *root); >> >> int subsys_id; >> - int active; >> - int disabled; >> - int early_init; >> + >> + unsigned int active:1; >> + unsigned int disabled:1; >> + unsigned int early_init:1; >> /* >> * True if this subsys uses ID. ID is not available before cgroup_init() >> * (not available in early_init time.) >> */ >> - bool use_id; >> + unsigned int use_id:1; >> + >> #define MAX_CGROUP_TYPE_NAMELEN 32 >> const char *name; >> >> -- >> 1.7.0.1 >> >> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/