From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763424AbYD1Dd2 (ORCPT ); Sun, 27 Apr 2008 23:33:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1762229AbYD1DdT (ORCPT ); Sun, 27 Apr 2008 23:33:19 -0400 Received: from relay1.sgi.com ([192.48.171.29]:53408 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1762199AbYD1DdS (ORCPT ); Sun, 27 Apr 2008 23:33:18 -0400 Date: Mon, 28 Apr 2008 13:32:49 +1000 From: David Chinner To: David Chinner Cc: Denys Vlasenko , xfs@oss.sgi.com, Eric Sandeen , Adrian Bunk , linux-kernel@vger.kernel.org Subject: Re: [PATCH] xfs: reduce stack usage in xfs_bmap_btalloc() Message-ID: <20080428033249.GE103491721@sgi.com> References: <200804261651.02078.vda.linux@googlemail.com> <20080427234056.GA108924158@sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080427234056.GA108924158@sgi.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 28, 2008 at 09:40:56AM +1000, David Chinner wrote: > On Sat, Apr 26, 2008 at 04:51:02PM +0200, Denys Vlasenko wrote: > > Hi David, > > > > This patch reduces xfs_bmap_btalloc() stack usage by 50 bytes > > by moving part of its body into a helper function. > > Can you please attach your patches inline, Denys (see > Documentation/SubmittingPatches)? > > > This results in some variables not taking stack space in > > xfs_bmap_btalloc() anymore. > > > > The helper itself does not call anything stack-deep. > > Stack-deep call to xfs_alloc_vextent() happen > > in xfs_bmap_btalloc(), as before. > > I have a set of patches that introduces new functionality into the > allocator (dynamic allocation policies) that reduces > xfs_bmap_btalloc() function by 36 bytes (just by chance, I didn't > design it for this purpose). It breaks it down on functional > boundaries like Christoph's patch. I'm going to revist that patch > w.r.t both these patches and see what falls out the bottom... 44 bytes saved in xfs_bmap_btalloc with the same factoring as Christoph's patch being done. Given that most of this is now the struct xfs_alloc_arg, I don't think this will be reduced a whole lot more. I think I might be able to kill the tryagain and isaligned variables as well which will save another 8 bytes, but I'll leave that for later.... Good progress, folks. Cheers, Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group