From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wu Fengguang Subject: Re: [PATCH 2/2 v2] writeback: Add writeback stats for pages written Date: Tue, 16 Aug 2011 20:26:54 +0800 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-Transfer-Encoding: QUOTED-PRINTABLE Cc: Jan Kara , Christoph Hellwig , Andrew Morton , Dave Chinner , Michael Rubin , "linux-fsdevel@vger.kernel.org" , "linux-mm@kvack.org" To: Curt Wohlgemuth Return-path: Received: from mga14.intel.com ([143.182.124.37]:12342 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751236Ab1HPM06 (ORCPT ); Tue, 16 Aug 2011 08:26:58 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Curt, > > =C2=A0The above stats are probably useful. I'm not so convinced abo= ut the stats > > below - it looks like it should be simple enough to get them by ena= bling > > some trace points and processing output (or if we are missing some > > tracepoints, it would be worthwhile to add them). >=20 > 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. > > > >> =C2=A0 =C2=A0periodic writeback =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0= =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0377 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. > >> =C2=A0 =C2=A0single inode wait =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 0 > >> =C2=A0 =C2=A0writeback_wb wait =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 1 Thanks, =46engguang -- 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