Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932646AbXBUX63 (ORCPT ); Wed, 21 Feb 2007 18:58:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932728AbXBUX63 (ORCPT ); Wed, 21 Feb 2007 18:58:29 -0500 Received: from smtp.osdl.org ([65.172.181.24]:58535 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932646AbXBUX62 (ORCPT ); Wed, 21 Feb 2007 18:58:28 -0500 Date: Wed, 21 Feb 2007 15:58:20 -0800 From: Andrew Morton To: Oleg Verych Cc: NeilBrown , linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 006 of 6] md: Add support for reshape of a raid6 Message-Id: <20070221155820.de9f2f16.akpm@linux-foundation.org> In-Reply-To: References: <20070220172544.15678.patches@notabene> <1070220063516.16208@suse.de> <20070221144806.e6eed85c.akpm@linux-foundation.org> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.6; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2468 Lines: 75 On Thu, 22 Feb 2007 00:36:22 +0100 Oleg Verych wrote: > > From: Andrew Morton > > Newsgroups: gmane.linux.raid,gmane.linux.kernel > > Subject: Re: [PATCH 006 of 6] md: Add support for reshape of a raid6 > > Date: Wed, 21 Feb 2007 14:48:06 -0800 > > Hallo. > > > On Tue, 20 Feb 2007 17:35:16 +1100 > > NeilBrown wrote: > > > >> + for (i = conf->raid_disks ; i-- ; ) { > > > > That statement should be dragged out, shot, stomped on then ceremonially > > incinerated. > > > > What's wrong with doing > > > > for (i = 0; i < conf->raid_disks; i++) { > > > > in a manner which can be understood without alcoholic fortification? > > > > ho hum. > > In case someone likes to do job, GCC usually ought to do, i would > suggest something like this instead: > > if (expanded && test_bit(STRIPE_EXPANDING, &sh->state)) { > /* Need to write out all blocks after computing P&Q */ > - sh->disks = conf->raid_disks; > + i = conf->raid_disks; > + sh->disks = i; > - sh->pd_idx = stripe_to_pdidx(sh->sector, conf, > - conf->raid_disks); > + sh->pd_idx = stripe_to_pdidx(sh->sector, conf, i); > > compute_parity6(sh, RECONSTRUCT_WRITE); > - for (i = conf->raid_disks ; i-- ; ) { > + do { > set_bit(R5_LOCKED, &sh->dev[i].flags); > locked++; > set_bit(R5_Wantwrite, &sh->dev[i].flags); > - } > + } while (--i); > > clear_bit(STRIPE_EXPANDING, &sh->state); > } else if (expanded) { > > In any case this is subject of scripts/bloat-o-meter. This: --- a/drivers/md/raid5.c~a +++ a/drivers/md/raid5.c @@ -2364,7 +2364,7 @@ static void handle_stripe6(struct stripe sh->pd_idx = stripe_to_pdidx(sh->sector, conf, conf->raid_disks); compute_parity6(sh, RECONSTRUCT_WRITE); - for (i = conf->raid_disks ; i-- ; ) { + for (i = 0; i < conf->raid_disks; ++) { set_bit(R5_LOCKED, &sh->dev[i].flags); locked++; set_bit(R5_Wantwrite, &sh->dev[i].flags); _ reduces the size of drivers/md/raid5.o's .text by two bytes. - 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/