From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932383Ab0E1PPJ (ORCPT ); Fri, 28 May 2010 11:15:09 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:53702 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758434Ab0E1PPH convert rfc822-to-8bit (ORCPT ); Fri, 28 May 2010 11:15:07 -0400 Subject: Re: [PATCH] tracing: Add task activate/deactivate tracepoints From: Peter Zijlstra To: Frederic Weisbecker Cc: LKML , Ingo Molnar , Steven Rostedt In-Reply-To: <1275056762-13130-1-git-send-regression-fweisbec@gmail.com> References: <1275056762-13130-1-git-send-regression-fweisbec@gmail.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Fri, 28 May 2010 17:15:10 +0200 Message-ID: <1275059710.27810.9624.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2010-05-28 at 16:26 +0200, Frederic Weisbecker wrote: > We have various tracepoints that tell us when a task is going to > be enqueued in a runqueue: fork, wakeup, migrate. > > But they don't always provide us the level of information necessary > to know what is actually in which runqueue, precisely because the > migrate event is only fired if the task is queued on another > cpu than its previous one. So we don't always know where a waking up > task goes. > > And moreover we don't have events that tells a task goes to sleep, > and even that wouldn't cover every cases when a task is dequeued. > > So bring these two new tracepoints to get informations about the > load of each runqueues. NAK, aside from a few corner cases wakeup and sleep are the important points. The activate and deactivate functions are implementation details.