From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753885Ab0ESIPh (ORCPT ); Wed, 19 May 2010 04:15:37 -0400 Received: from he.sipsolutions.net ([78.46.109.217]:48192 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751353Ab0ESIPf (ORCPT ); Wed, 19 May 2010 04:15:35 -0400 Subject: Re: collecting static data related to tracing From: Johannes Berg To: Frederic Weisbecker Cc: rostedt@goodmis.org, 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="UTF-8" Date: Wed, 19 May 2010 10:15:31 +0200 Message-ID: <1274256931.3874.3.camel@jlt3.sipsolutions.net> Mime-Version: 1.0 X-Mailer: Evolution 2.29.92.1 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: > > Sounds good, although it does require that I tell people who want to > > record to also install the recording plugin, but that should be > > manageable :) I can just dig out the data from the regular debugfs once > > I add files containing it. > 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. Indeed, that is a good point, and it would also allow us to handle hotplugging with the same event by sending it when a new device shows up, and additionally when it is enabled to dump the current state. johannes