From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759962AbZKZKop (ORCPT ); Thu, 26 Nov 2009 05:44:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750896AbZKZKoo (ORCPT ); Thu, 26 Nov 2009 05:44:44 -0500 Received: from hera.kernel.org ([140.211.167.34]:46789 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750767AbZKZKon (ORCPT ); Thu, 26 Nov 2009 05:44:43 -0500 Message-ID: <4B0E5C06.8080500@kernel.org> Date: Thu, 26 Nov 2009 19:44:22 +0900 From: Tejun Heo User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; ko-KR; rv:1.9.1.4pre) Gecko/20090915 SUSE/3.0b4-3.6 Thunderbird/3.0b4 MIME-Version: 1.0 To: Ingo Molnar CC: Stephen Rothwell , linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, Mike Galbraith , Thomas Gleixner , "H. Peter Anvin" , Peter Zijlstra Subject: Re: [PATCH 1/4 tip/sched/core] sched: rename preempt_notifier to sched_notifier and always enable it References: <20091126190018.88a6dd77.sfr@canb.auug.org.au> <20091126081237.GA31034@elte.hu> <4B0E4741.10509@kernel.org> <20091126092631.GA17253@elte.hu> <4B0E4EFB.2070705@kernel.org> <20091126095154.GE32275@elte.hu> <4B0E5458.30303@kernel.org> <20091126102936.GA1196@elte.hu> In-Reply-To: <20091126102936.GA1196@elte.hu> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Ingo. 11/26/2009 07:29 PM, Ingo Molnar wrote: > That could be done with just two callbacks - one for sched-out, one for > sched-in. > > The best way to do that would be to use two TRACE_EVENT() callbacks, > make them unconditional and register to them. (with wrappers to make it > all convenient to use) > > This requires some work but needs to be done. Thought about that but trace events and scheduler callbacks have very different trigger enable/disable conditions. I couldn't think of a way to do both in reasonably efficient manner. Although they both are notification mechanisms, they do have pretty different requirements and I'm not quite sure whether unifying them is a good idea. Of course if you have an idea to do both efficiently, no reason not to do it. Thanks. -- tejun