From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752932Ab0ESOoV (ORCPT ); Wed, 19 May 2010 10:44:21 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.123]:37513 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751999Ab0ESOoU (ORCPT ); Wed, 19 May 2010 10:44:20 -0400 X-Authority-Analysis: v=1.1 cv=ThiPuEJrAfM5PTlEgIT3cJp8+3pkHBIG3CaogqDGxqo= c=1 sm=0 a=pjGjkNHRNmAA:10 a=0qYQvVkOOIcA:10 a=7U3hwN5JcxgA:10 a=Q9fys5e9bTEA:10 a=gMqfjgEr1zLu/65IO0LwxA==:17 a=rVFi2vXHS02sp9KjV5gA:9 a=NgsPNFqvbhenuB1Dg8jO5sBi4r8A:4 a=PUjeQqilurYA:10 a=gMqfjgEr1zLu/65IO0LwxA==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.67.89.75 Subject: Re: collecting static data related to tracing From: Steven Rostedt Reply-To: rostedt@goodmis.org To: Frederic Weisbecker Cc: Johannes Berg , linux-kernel In-Reply-To: <20100519072838.GD5704@nowhere> References: <1274191742.31554.10.camel@jlt3.sipsolutions.net> <1274193698.26328.746.camel@gandalf.stny.rr.com> <1274193909.31554.12.camel@jlt3.sipsolutions.net> <20100519072838.GD5704@nowhere> Content-Type: text/plain; charset="ISO-8859-15" Organization: Kihon Technologies Inc. Date: Wed, 19 May 2010 10:44:17 -0400 Message-ID: <1274280257.26328.767.camel@gandalf.stny.rr.com> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2010-05-19 at 09:28 +0200, Frederic Weisbecker wrote: > On Tue, May 18, 2010 at 04:45:09PM +0200, Johannes Berg wrote: > This is a place where events injection might be suitable perhaps. > Either kernel or user space event injection. > > kernel space injection would be a simple trace event declared that > have a callback called when it gets enabled. This callback would > inject any events it wants. > > userspace injection could be a bit different, the user can inject > its own format and events content toward a debugfs or whatever file. > This would be suitable if userspace have few things to inject, > otherwise we would need to think about something else perhaps. > The userspace injection actually sounds like a good idea. I don't think it needs to tell the kernel about it. Since it is running the trace. Perhaps just have a way that the userspace can add its own events to the recording file. I guess this would be closer to what LTTng does with channels. That is, you could have a separate recording stream to write events that tell the tracer what is happening. It would be nice to have a way that userspace can read the trace clock timer though. -- Steve