From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932149AbXCMSuR (ORCPT ); Tue, 13 Mar 2007 14:50:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932260AbXCMSuQ (ORCPT ); Tue, 13 Mar 2007 14:50:16 -0400 Received: from styx.suse.cz ([82.119.242.94]:42693 "EHLO duck.suse.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932149AbXCMSuO (ORCPT ); Tue, 13 Mar 2007 14:50:14 -0400 Date: Tue, 13 Mar 2007 19:55:54 +0100 From: Jan Kara To: Ashif Harji Cc: Nick Piggin , linux-kernel@vger.kernel.org Subject: Re: do_generic_mapping_read performance issue Message-ID: <20070313185554.GA5105@duck.suse.cz> References: <20070312142012.GH30777@atrey.karlin.mff.cuni.cz> <20070312143900.GB6016@wotan.suse.de> <20070312151355.GB23532@duck.suse.cz> <20070312173500.GF23532@duck.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue 13-03-07 14:43:47, Ashif Harji wrote: > > >>I would like to submit a patch to fix the performance problem. The > >>simplest solution is to remove the check. Even in the situation where an > >>application does not read in PAGE_SIZE multiples as described above, if > >>the page is accessed frequently it should remain in the cache. However, I > >>am open to suggestions for a more sophisticated scheme. > > > > Well, yes, that's an obvious solution. I just wanted to make sure that > >such change won't break some other load. But so far it seems it won't... > > I would like to find out if the change I am suggesting will cause any > other problems. Is there someone else I should contact before submitting > a patch? Or should I just wait another day or two for comments? I don't think you'll get more feedback now. Just write the patch, benchmark it with your workload and also some others (basically, there should be no difference) and then submit the patch together with the performance numbers and some rationale (if it's your first submission, see Documentation/SubmittingPatches). Give also CC to Andrew and ask him to put it into -mm kernels for testing. Honza -- Jan Kara SuSE CR Labs