Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755469Ab0BOOQi (ORCPT ); Mon, 15 Feb 2010 09:16:38 -0500 Received: from mx1.redhat.com ([209.132.183.28]:22432 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751805Ab0BOOQg (ORCPT ); Mon, 15 Feb 2010 09:16:36 -0500 Date: Mon, 15 Feb 2010 09:16:26 -0500 From: Vivek Goyal To: Richard Kennedy Cc: Jens Axboe , Corrado Zoccolo , Jeff Moyer , Gui Jianfeng , lkml Subject: Re: [PATCH] cfq: reorder cfq_queue removing padding on 64bit & allowing more objects/slab in it's kmem_cache Message-ID: <20100215141626.GB5355@redhat.com> References: <1266243036.2149.21.camel@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1266243036.2149.21.camel@localhost> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1719 Lines: 59 On Mon, Feb 15, 2010 at 02:10:36PM +0000, Richard Kennedy wrote: > This removes 8 bytes of padding from struct cfq_queue on 64 bit builds, > shrinking it's size to 256 bytes, so fitting into 1 fewer cachelines and > allowing 1 more object/slab in it's kmem_cache. > > > Signed-off-by: Richard Kennedy > ---- > patch against 2.6.33-rc8 > tested on x86_64 AMDX2 > > regards > Richard > > > diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c > index 023f4e6..db4c127 100644 > --- a/block/cfq-iosched.c > +++ b/block/cfq-iosched.c > @@ -116,10 +116,10 @@ struct cfq_queue { > unsigned long dispatch_start; > unsigned int allocated_slice; > /* time when first request from queue completed and slice started. */ > + unsigned int slice_dispatch; Can you move it above the comment. The comment describes "slice_start" and now comment and variable have been separated. Vivek > unsigned long slice_start; > unsigned long slice_end; > long slice_resid; > - unsigned int slice_dispatch; > > /* pending metadata requests */ > int meta_pending; > @@ -130,13 +130,13 @@ struct cfq_queue { > unsigned short ioprio, org_ioprio; > unsigned short ioprio_class, org_ioprio_class; > > + pid_t pid; > + > unsigned int seek_samples; > u64 seek_total; > sector_t seek_mean; > sector_t last_request_pos; > > - pid_t pid; > - > struct cfq_rb_root *service_tree; > struct cfq_queue *new_cfqq; > struct cfq_group *cfqg; > -- 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/