From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754058Ab0HXBl1 (ORCPT ); Mon, 23 Aug 2010 21:41:27 -0400 Received: from smtp-out.google.com ([216.239.44.51]:16588 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751805Ab0HXBlX convert rfc822-to-8bit (ORCPT ); Mon, 23 Aug 2010 21:41:23 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=google.com; s=beta; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type:content-transfer-encoding; b=eMdYFxYHpyYbNwg8JM4OVIQVlCQj0T3NNaDa3SGuuU+xyFlwSeqzGRlXMLypawVQrK PS5rxx9LMwn6oSNf+tPw== MIME-Version: 1.0 In-Reply-To: <20100824100943.F3B6.A69D9226@jp.fujitsu.com> References: <20100821054808.GA29869@localhost> <20100824100943.F3B6.A69D9226@jp.fujitsu.com> From: Michael Rubin Date: Mon, 23 Aug 2010 18:41:00 -0700 Message-ID: Subject: Re: [PATCH 4/4] writeback: Reporting dirty thresholds in /proc/vmstat To: KOSAKI Motohiro Cc: Wu Fengguang , Peter Zijlstra , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-mm@kvack.org" , "jack@suse.cz" , "riel@redhat.com" , "akpm@linux-foundation.org" , "david@fromorbit.com" , "npiggin@kernel.dk" , "hch@lst.de" , "axboe@kernel.dk" Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 23, 2010 at 6:20 PM, KOSAKI Motohiro wrote: >> On Fri, Aug 20, 2010 at 10:48 PM, Wu Fengguang wrote: >> LOL. I know about these counters. This goes back and forth a lot. >> The reason we don't want to use this interface is several fold. > > Please don't use LOL if you want to get good discuttion. afaict, Wu have > deep knowledge in this area. However all kernel-developer don't know all > kernel knob. Apologies. No offense was intended. I was laughing at the situation and how I too once thought the per bdi counters were enough. Feng has been very helpful and patient. The discussion has done nothing but help the code so far so it is appreciated. > In nowadays, many distro mount debugfs at boot time. so, can you please > elaborate you worried risk?  even though we have namespace. Right now we don't mount all of debugfs at boot time. We have not done the work to verify its safe in our environment. It's mostly a nit. Also I was under the impression that debugfs was intended more for kernel devs while /proc and /sys was intended for application developers. >> 3) Full system counters are easier to handle the juggling of removable >> storage where these numbers will appear and disappear due to being >> dynamic. This is the biggie to me. The idea is to get a complete view of the system's writeback behaviour over time. With systems with hot plug devices, or many many drives collecting that view gets difficult. >> The goal is to get a full view of the system writeback behaviour not a >> "kinda got it-oops maybe not" view. > > I bet nobody oppose this point :) Yup. mrubin From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Rubin Subject: Re: [PATCH 4/4] writeback: Reporting dirty thresholds in /proc/vmstat Date: Mon, 23 Aug 2010 18:41:00 -0700 Message-ID: References: <20100821054808.GA29869@localhost> <20100824100943.F3B6.A69D9226@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Wu Fengguang , Peter Zijlstra , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-mm@kvack.org" , "jack@suse.cz" , "riel@redhat.com" , "akpm@linux-foundation.org" , "david@fromorbit.com" , "npiggin@kernel.dk" , "hch@lst.de" , "axboe@kernel.dk" To: KOSAKI Motohiro Return-path: Received: from smtp-out.google.com ([216.239.44.51]:16588 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751805Ab0HXBlX convert rfc822-to-8bit (ORCPT ); Mon, 23 Aug 2010 21:41:23 -0400 In-Reply-To: <20100824100943.F3B6.A69D9226@jp.fujitsu.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Mon, Aug 23, 2010 at 6:20 PM, KOSAKI Motohiro wrote: >> On Fri, Aug 20, 2010 at 10:48 PM, Wu Fengguang wrote: >> LOL. I know about these counters. This goes back and forth a lot. >> The reason we don't want to use this interface is several fold. > > Please don't use LOL if you want to get good discuttion. afaict, Wu h= ave > deep knowledge in this area. However all kernel-developer don't know = all > kernel knob. Apologies. No offense was intended. I was laughing at the situation and how I too once thought the per bdi counters were enough. Feng has been very helpful and patient. The discussion has done nothing but help the code so far so it is appreciated. > In nowadays, many distro mount debugfs at boot time. so, can you plea= se > elaborate you worried risk? =A0even though we have namespace. Right now we don't mount all of debugfs at boot time. We have not done the work to verify its safe in our environment. It's mostly a nit. Also I was under the impression that debugfs was intended more for kernel devs while /proc and /sys was intended for application developers. >> 3) Full system counters are easier to handle the juggling of removab= le >> storage where these numbers will appear and disappear due to being >> dynamic. This is the biggie to me. The idea is to get a complete view of the system's writeback behaviour over time. With systems with hot plug devices, or many many drives collecting that view gets difficult. >> The goal is to get a full view of the system writeback behaviour not= a >> "kinda got it-oops maybe not" view. > > I bet nobody oppose this point :) Yup. mrubin -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel= " in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with ESMTP id 1443760080F for ; Mon, 23 Aug 2010 21:41:25 -0400 (EDT) Received: from hpaq3.eem.corp.google.com (hpaq3.eem.corp.google.com [172.25.149.3]) by smtp-out.google.com with ESMTP id o7O1fMdn001043 for ; Mon, 23 Aug 2010 18:41:22 -0700 Received: from gwb17 (gwb17.prod.google.com [10.200.2.17]) by hpaq3.eem.corp.google.com with ESMTP id o7O1fKJL030226 for ; Mon, 23 Aug 2010 18:41:20 -0700 Received: by gwb17 with SMTP id 17so3220535gwb.10 for ; Mon, 23 Aug 2010 18:41:20 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20100824100943.F3B6.A69D9226@jp.fujitsu.com> References: <20100821054808.GA29869@localhost> <20100824100943.F3B6.A69D9226@jp.fujitsu.com> From: Michael Rubin Date: Mon, 23 Aug 2010 18:41:00 -0700 Message-ID: Subject: Re: [PATCH 4/4] writeback: Reporting dirty thresholds in /proc/vmstat Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org To: KOSAKI Motohiro Cc: Wu Fengguang , Peter Zijlstra , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-mm@kvack.org" , "jack@suse.cz" , "riel@redhat.com" , "akpm@linux-foundation.org" , "david@fromorbit.com" , "npiggin@kernel.dk" , "hch@lst.de" , "axboe@kernel.dk" List-ID: On Mon, Aug 23, 2010 at 6:20 PM, KOSAKI Motohiro wrote: >> On Fri, Aug 20, 2010 at 10:48 PM, Wu Fengguang = wrote: >> LOL. I know about these counters. This goes back and forth a lot. >> The reason we don't want to use this interface is several fold. > > Please don't use LOL if you want to get good discuttion. afaict, Wu have > deep knowledge in this area. However all kernel-developer don't know all > kernel knob. Apologies. No offense was intended. I was laughing at the situation and how I too once thought the per bdi counters were enough. Feng has been very helpful and patient. The discussion has done nothing but help the code so far so it is appreciated. > In nowadays, many distro mount debugfs at boot time. so, can you please > elaborate you worried risk? =A0even though we have namespace. Right now we don't mount all of debugfs at boot time. We have not done the work to verify its safe in our environment. It's mostly a nit. Also I was under the impression that debugfs was intended more for kernel devs while /proc and /sys was intended for application developers. >> 3) Full system counters are easier to handle the juggling of removable >> storage where these numbers will appear and disappear due to being >> dynamic. This is the biggie to me. The idea is to get a complete view of the system's writeback behaviour over time. With systems with hot plug devices, or many many drives collecting that view gets difficult. >> The goal is to get a full view of the system writeback behaviour not a >> "kinda got it-oops maybe not" view. > > I bet nobody oppose this point :) Yup. mrubin -- 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/ . Don't email: email@kvack.org