Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757751AbYLDU6A (ORCPT ); Thu, 4 Dec 2008 15:58:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754874AbYLDU5w (ORCPT ); Thu, 4 Dec 2008 15:57:52 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.124]:50894 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754853AbYLDU5w (ORCPT ); Thu, 4 Dec 2008 15:57:52 -0500 Date: Thu, 4 Dec 2008 15:57:48 -0500 (EST) From: Steven Rostedt X-X-Sender: rostedt@gandalf.stny.rr.com To: "Eric W. Biederman" cc: Ingo Molnar , Andrew Morton , linux-kernel@vger.kernel.org, Frederic Weisbecker , Peter Zijlstra , Dave Hansen , containers@lists.osdl.org, Sukadev Bhattiprolu , "Serge E. Hallyn" , Steven Rostedt Subject: Re: [PATCH 3/3] ftrace: add ability to only trace swapper tasks In-Reply-To: Message-ID: References: <20081204052638.425740534@goodmis.org> <20081204052735.362609481@goodmis.org> <20081204001803.598063f5.akpm@linux-foundation.org> <20081204091023.GJ32594@elte.hu> User-Agent: Alpine 1.10 (DEB 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1330 Lines: 38 On Thu, 4 Dec 2008, Eric W. Biederman wrote: > >> > > >> >> > +static struct pid * const ftrace_swapper_pid = (struct pid *)1; > >> >> > >> >> eh? > >> > > >> > all side-effects of getting rid of the integer based PID namespace and > >> > replacing them with struct pid pointers. > >> > >> Thanks for asking Andrew it looks like an unnecessary side effect. > > > > Well, it was necessary without hacking fork.c ;-) > > The (struct pid *)1 has always been unnecessary. Well, I could set it to the &init_struct_pid as you said, but it will not change any of the code below it. So it does not matter what ftrace_swapper_pid is set to, as long as it is not set to something that can be a legitimate pid struct for something not the swapper task. It will only matter when we fix the fork code. > > As for fork. It would be nice to remove most of the special cases > for the idle thread. At least the counts are significant. The rest > is pretty much a don't care at this point. Well, the swapper task should still have a pid of zero. That is probably important. -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/