Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757051AbZDOAQp (ORCPT ); Tue, 14 Apr 2009 20:16:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752428AbZDOAQg (ORCPT ); Tue, 14 Apr 2009 20:16:36 -0400 Received: from mx2.redhat.com ([66.187.237.31]:36181 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751912AbZDOAQg (ORCPT ); Tue, 14 Apr 2009 20:16:36 -0400 Date: Tue, 14 Apr 2009 21:16:17 -0300 From: Arnaldo Carvalho de Melo To: Theodore Tso Cc: Frederic Weisbecker , Li Zefan , Jens Axboe , LKML , Steven Rostedt Subject: Re: blktrace: event traces displayed wrong while ftrace blktrace is active Message-ID: <20090415001617.GB8359@ghostprotocols.net> References: <49E45F7B.7060709@cn.fujitsu.com> <20090414212532.GD5968@nowhere> <20090414213207.GP955@mit.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090414213207.GP955@mit.edu> X-Url: http://oops.ghostprotocols.net:81/blog User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1443 Lines: 38 Em Tue, Apr 14, 2009 at 05:32:07PM -0400, Theodore Tso escreveu: > On Tue, Apr 14, 2009 at 11:25:33PM +0200, Frederic Weisbecker wrote: > > > > Indeed. Note that you can overwrite this default by typing: > > > > echo context-info > trace_option > > > > after setting bkltrace as the current tracer. > > The problem with doing that is that blktrace will then display this: > > fsync-tester-27934 [001] 208.031278: fsync-tester-27934 [001] 208.031278: 254,4 Q WS 268392 + 8 [fsync-tester] > > I think the real problem is that blk trace is displaying the standard > context-info, so it's suppressing the normal context info. So I have > the choice on having no context information on my event trace lines, > or two copies of the context information for the block trace lines. > > :-( > > I'm guessing things were done this way in order to support the old > legancy blktrace format? Well, last time I worked in this code the default was to use the default context information, not duplicate it, and if one used: echo blk_classic > /sys/kernel/debug/tracing/trace_options Then it would look like the output of blktrace(8). Lemme try to boot the current code... - Arnaldo -- 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/