Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756926AbYLDUql (ORCPT ); Thu, 4 Dec 2008 15:46:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754698AbYLDUqb (ORCPT ); Thu, 4 Dec 2008 15:46:31 -0500 Received: from out01.mta.xmission.com ([166.70.13.231]:58893 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754289AbYLDUqb (ORCPT ); Thu, 4 Dec 2008 15:46:31 -0500 From: ebiederm@xmission.com (Eric W. Biederman) To: Steven Rostedt 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 References: <20081204052638.425740534@goodmis.org> <20081204052735.362609481@goodmis.org> <20081204001803.598063f5.akpm@linux-foundation.org> <20081204091023.GJ32594@elte.hu> Date: Thu, 04 Dec 2008 12:41:08 -0800 In-Reply-To: (Steven Rostedt's message of "Thu, 4 Dec 2008 09:46:28 -0500 (EST)") Message-ID: User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-XM-SPF: eid=;;;mid=;;;hst=mx04.mta.xmission.com;;;ip=24.130.11.59;;;frm=ebiederm@xmission.com;;;spf=neutral X-SA-Exim-Connect-IP: 24.130.11.59 X-SA-Exim-Rcpt-To: too long (recipient list exceeded maximum allowed size of 128 bytes) X-SA-Exim-Mail-From: ebiederm@xmission.com X-SA-Exim-Version: 4.2.1 (built Thu, 07 Dec 2006 04:40:56 +0000) X-SA-Exim-Scanned: No (on mx04.mta.xmission.com); Unknown failure Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1327 Lines: 38 Steven Rostedt writes: > On Thu, 4 Dec 2008, Eric W. Biederman wrote: > >> Ingo Molnar writes: >> >> > * Andrew Morton wrote: >> > >> >> > Signed-off-by: Steven Rostedt >> >> >> >> What does this patch actually do? Is swapper currently excluded from >> >> tracing for undisclosed reasons and this patch permits it to be traced? >> >> If so, why was swapper thus excluded? Or am I totally off track? >> > >> >> > +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. 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. Eric -- 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/