Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758706AbYLDV4x (ORCPT ); Thu, 4 Dec 2008 16:56:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756433AbYLDV4b (ORCPT ); Thu, 4 Dec 2008 16:56:31 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.125]:35549 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756200AbYLDV4a (ORCPT ); Thu, 4 Dec 2008 16:56:30 -0500 Date: Thu, 4 Dec 2008 16:56:28 -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: 972 Lines: 26 On Thu, 4 Dec 2008, Eric W. Biederman wrote: > > Right. I simply meant most of the > if (likely(p->pid)) conditional except for the counts is pretty much a don't > care. Keeping the idle tasks off of the process list and out of the counts > is useful. > > For this particular case what problem did you see with calling attach_pid > with PIDTYPE_PID on init_struct_pid? On boot up, the CPU 0 idle task is attached to init_struct_pid, and not the others. If you do a "attach_pid" on the next idle task that is created, it will become the attched process, bumping off CPU 0's idle task from the init_struct_pid. When doing the code you suggested, I end up with only marking the last idle task to be created. -- 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/