From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: Re: [PATCH] proc: show readahead state in fdinfo Date: Thu, 15 Dec 2011 10:49:22 +0100 Message-ID: <20111215094922.GA29981@elte.hu> References: <20111129130900.628549879@intel.com> <20111129131456.278516066@intel.com> <20111129175743.GP24062@one.firstfloor.org> <20111215085540.GA23966@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Andi Kleen , Andrew Morton , Jens Axboe , Peter Zijlstra , Rik van Riel , Linux Memory Management List , "linux-fsdevel@vger.kernel.org" , LKML , =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker , Arnaldo Carvalho de Melo To: Wu Fengguang Return-path: Content-Disposition: inline In-Reply-To: <20111215085540.GA23966@localhost> Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org * Wu Fengguang wrote: > On Wed, Nov 30, 2011 at 01:57:43AM +0800, Andi Kleen wrote: > > On Tue, Nov 29, 2011 at 09:09:03PM +0800, Wu Fengguang wrote: > > > Record the readahead pattern in ra->pattern and extend the ra_submit() > > > parameters, to be used by the next readahead tracing/stats patches. > > > > I like this, could it be exported it a bit more formally in /proc for > > each file descriptor? > > How about this? > --- > Subject: proc: show readahead state in fdinfo > Date: Thu Dec 15 14:35:56 CST 2011 > > Append three readahead states to /proc//fdinfo/: Not a very good idea - please keep debug info under /debug as much as possible (as your original series did), instead of creating an ad-hoc insta-ABI in /proc. In the long run we'd really like to retrieve such kind of information not even via ad-hoc exported info in /debug but via the standard event facilities: the tracepoints, if they are versatile enough, could be used to collect these stats and more. Thanks, Ingo -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932438Ab1LOJva (ORCPT ); Thu, 15 Dec 2011 04:51:30 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:53282 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758750Ab1LOJv3 (ORCPT ); Thu, 15 Dec 2011 04:51:29 -0500 Date: Thu, 15 Dec 2011 10:49:22 +0100 From: Ingo Molnar To: Wu Fengguang Cc: Andi Kleen , Andrew Morton , Jens Axboe , Peter Zijlstra , Rik van Riel , Linux Memory Management List , "linux-fsdevel@vger.kernel.org" , LKML , =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker , Arnaldo Carvalho de Melo Subject: Re: [PATCH] proc: show readahead state in fdinfo Message-ID: <20111215094922.GA29981@elte.hu> References: <20111129130900.628549879@intel.com> <20111129131456.278516066@intel.com> <20111129175743.GP24062@one.firstfloor.org> <20111215085540.GA23966@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20111215085540.GA23966@localhost> User-Agent: Mutt/1.5.21 (2010-09-15) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=AWL,BAYES_00 autolearn=no SpamAssassin version=3.3.1 -2.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] 0.0 AWL AWL: From: address is in the auto white-list Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Wu Fengguang wrote: > On Wed, Nov 30, 2011 at 01:57:43AM +0800, Andi Kleen wrote: > > On Tue, Nov 29, 2011 at 09:09:03PM +0800, Wu Fengguang wrote: > > > Record the readahead pattern in ra->pattern and extend the ra_submit() > > > parameters, to be used by the next readahead tracing/stats patches. > > > > I like this, could it be exported it a bit more formally in /proc for > > each file descriptor? > > How about this? > --- > Subject: proc: show readahead state in fdinfo > Date: Thu Dec 15 14:35:56 CST 2011 > > Append three readahead states to /proc//fdinfo/: Not a very good idea - please keep debug info under /debug as much as possible (as your original series did), instead of creating an ad-hoc insta-ABI in /proc. In the long run we'd really like to retrieve such kind of information not even via ad-hoc exported info in /debug but via the standard event facilities: the tracepoints, if they are versatile enough, could be used to collect these stats and more. Thanks, Ingo