Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264918AbTGHQvu (ORCPT ); Tue, 8 Jul 2003 12:51:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264925AbTGHQvu (ORCPT ); Tue, 8 Jul 2003 12:51:50 -0400 Received: from www.13thfloor.at ([212.16.59.250]:56198 "EHLO www.13thfloor.at") by vger.kernel.org with ESMTP id S264917AbTGHQvr (ORCPT ); Tue, 8 Jul 2003 12:51:47 -0400 Date: Tue, 8 Jul 2003 19:06:28 +0200 From: Herbert Poetzl To: Alan Cox Cc: Marcelo Tosatti , hannal@us.ibm.com, Linux Kernel Mailing List , Linux FSdevel Subject: Re: [PATCH] Fastwalk: reduce cacheline bouncing of d_count (Changelog@1.1024.1.11) Message-ID: <20030708170628.GA13593@www.13thfloor.at> Reply-To: herbert@13thfloor.at Mail-Followup-To: Alan Cox , Marcelo Tosatti , hannal@us.ibm.com, Linux Kernel Mailing List , Linux FSdevel References: <16138.53118.777914.828030@charged.uio.no> <1057673804.4357.27.camel@dhcp22.swansea.linux.org.uk> <16138.56467.342593.715679@charged.uio.no> <1057677613.4358.33.camel@dhcp22.swansea.linux.org.uk> <20030708164426.GB10004@www.13thfloor.at> <1057683213.5228.3.camel@dhcp22.swansea.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <1057683213.5228.3.camel@dhcp22.swansea.linux.org.uk> User-Agent: Mutt/1.3.28i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1711 Lines: 52 On Tue, Jul 08, 2003 at 05:53:34PM +0100, Alan Cox wrote: > On Maw, 2003-07-08 at 17:44, Herbert Poetzl wrote: > > > Its no big problem to me since I can just back it out of -ac > > > > just curious, because I use this patch since early 2.4.20, > > are there any reasons to 'back it out of -ac' for you? > > > > anyway I totally agree that the NFS issue pointed out by > > Trond should be addressed ... > > Its high risk, its got bugs as Trond already showed and it only > helps performance on giant SMP boxes. Its all risk and no > reward. Quota updates get you working 32bit uid quota and > the interactivity stuff helps all even tho its got some > risk. every change (if it's not a bugfix, and even those) bear a risk, what I like about the fastwalk patch is not the performance gain on giant SMP boxes, because I do not have any (unfortunately ;) but the code change from ... if (path_init(pathname, LOOKUP_PARENT, &nd)) error = path_walk(pathname, &nd); to error = path_lookup(pathname, LOOKUP_PARENT, &nd); and dentry = cached_lookup(nd->dentry, &this, 0); if (!dentry) { dentry = real_lookup(nd->dentry, &this, 0); err = PTR_ERR(dentry); if (IS_ERR(dentry)) break; } to err = do_lookup(nd, &this, &next, &pinned, 0); which (at least for me) is more read-/understandable ... anyway, thanks for you answer, Herbert - 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/