Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755979Ab0DWTlc (ORCPT ); Fri, 23 Apr 2010 15:41:32 -0400 Received: from e35.co.us.ibm.com ([32.97.110.153]:49894 "EHLO e35.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755321Ab0DWTlZ (ORCPT ); Fri, 23 Apr 2010 15:41:25 -0400 Date: Fri, 23 Apr 2010 12:41:22 -0700 From: "Darrick J. Wong" To: Jens Axboe Cc: linux-kernel , linux-ext4 Subject: Re: [PATCH] block: Add a trace point whenever a barrier IO request is sent Message-ID: <20100423194122.GB15607@tux1.beaverton.ibm.com> Reply-To: djwong@us.ibm.com References: <20100421205626.GA15607@tux1.beaverton.ibm.com> <20100421212727.GY27497@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100421212727.GY27497@kernel.dk> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 853 Lines: 19 On Wed, Apr 21, 2010 at 11:27:27PM +0200, Jens Axboe wrote: > On Wed, Apr 21 2010, Darrick J. Wong wrote: > > Simple debugging patch used to watch for barrier requests. I've been using > > this to watch ext4's barrier=1 behavior. > > But barriers are already being logged, if you watch blkparse data, it'll > be RB or WB events. So I don't see what this addition provides that we > don't already have? I also have the function graph tracer turned on, so I can (try to) map barrier requests to specific chunks of ext4 code. But, maybe there's a way to do this with blkparse that I haven't found yet? --D -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/