From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758122AbZBRWCz (ORCPT ); Wed, 18 Feb 2009 17:02:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752230AbZBRWCq (ORCPT ); Wed, 18 Feb 2009 17:02:46 -0500 Received: from mx2.redhat.com ([66.187.237.31]:50101 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751697AbZBRWCq (ORCPT ); Wed, 18 Feb 2009 17:02:46 -0500 Date: Wed, 18 Feb 2009 17:02:01 -0500 From: "Frank Ch. Eigler" To: Peter Zijlstra Cc: Jason Baron , mingo@elte.hu, rostedt@goodmis.org, linux-kernel@vger.kernel.org, acme@ghostprotocols.net, fweisbec@gmail.com, compudj@krystal.dyndns.org Subject: Re: [PATCH] new irq tracer Message-ID: <20090218220201.GG24507@redhat.com> References: <20090218195328.GA3112@redhat.com> <1234991725.4799.1.camel@laptop> <20090218213545.GB3112@redhat.com> <1234993580.4799.11.camel@laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1234993580.4799.11.camel@laptop> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi - On Wed, Feb 18, 2009 at 10:46:20PM +0100, Peter Zijlstra wrote: > [...] > How useful is that return value? "somewhat"? > Much of the other data is already available, /proc/interrupts will > happily tell you the source of your interrupt storm. The irq-off > latency tracer will tell you if stuff takes too much time, the graph > tracer can tell you what is taking how much time. Doesn't it seem like this is too much work to have answer a simple if particular question? > I really am having a difficult time seeing the use in such narrow > tracers. Part of the problem may come from defining "tracers" as something limited to ftrace engines. Once such tracepoints are in the kernel, more powerful analytical tools may be attached to them. - FChE