From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id DA7D36B0169 for ; Tue, 16 Aug 2011 08:26:59 -0400 (EDT) Date: Tue, 16 Aug 2011 20:26:54 +0800 From: Wu Fengguang Subject: Re: [PATCH 2/2 v2] writeback: Add writeback stats for pages written Message-ID: <20110816122654.GB13391@localhost> References: <1313189245-7197-1-git-send-email-curtw@google.com> <1313189245-7197-2-git-send-email-curtw@google.com> <20110815150348.GC6597@quack.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Curt Wohlgemuth Cc: Jan Kara , Christoph Hellwig , Andrew Morton , Dave Chinner , Michael Rubin , "linux-fsdevel@vger.kernel.org" , "linux-mm@kvack.org" Curt, > > A The above stats are probably useful. I'm not so convinced about the stats > > below - it looks like it should be simple enough to get them by enabling > > some trace points and processing output (or if we are missing some > > tracepoints, it would be worthwhile to add them). > > For these specifically, I'd agree with you. In general, though, I > think that having generally available aggregated stats is really > useful, in a different way than tracepoints are. If there comes such useful aggregated stats in future, they may go to vmstat and/or /debug/bdi//stats. Then we make the writeback stats a simple uniform interface rather than a hybrid one. > > > >> A A periodic writeback A A A A A A A A A A A 377 The above one can go to the "work" column, "periodic" row of the writeback stats table :) I'm in particular interested in the "work" column of the "try_to_free_pages" row. I also suspect there could be many short-lived background work, hence there lots of them. > >> A A single inode wait A A A A A A A A A A A A 0 > >> A A writeback_wb wait A A A A A A A A A A A A 1 Thanks, Fengguang -- 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