Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262532AbVESOnE (ORCPT ); Thu, 19 May 2005 10:43:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262539AbVESOnD (ORCPT ); Thu, 19 May 2005 10:43:03 -0400 Received: from graphe.net ([209.204.138.32]:21769 "EHLO graphe.net") by vger.kernel.org with ESMTP id S262532AbVESOl6 (ORCPT ); Thu, 19 May 2005 10:41:58 -0400 Date: Thu, 19 May 2005 07:41:41 -0700 (PDT) From: Christoph Lameter X-X-Sender: christoph@graphe.net To: Oleg Nesterov cc: linux-kernel@vger.kernel.org, Mitchell Blank Jr , Andrew Morton , shai@scalex86.org Subject: Re: [PATCH] Optimize sys_times for a single thread process In-Reply-To: <428C3ABB.61B552E@tv-sign.ru> Message-ID: References: <428B09A6.DD188E8D@tv-sign.ru> <428C3ABB.61B552E@tv-sign.ru> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Spam-Score: -5.9 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1217 Lines: 33 On Thu, 19 May 2005, Oleg Nesterov wrote: > > The thread ist needs to contain only one element which is current. > > thread_group_empty checks for no threads. > > I think that thread_group_empty() means that there are no *other* > threads in the thread group, that means that we have only one thread. > > In any case (p == next_thread(p)) == thread_group_empty(p). > > But it is a very minor issue indeed, let's forget it. No no. If you are right then you are right and I am wrong. Index: linux-2.6.12-rc4/kernel/sys.c =================================================================== --- linux-2.6.12-rc4.orig/kernel/sys.c 2005-05-19 03:23:29.000000000 +0000 +++ linux-2.6.12-rc4/kernel/sys.c 2005-05-19 14:40:32.000000000 +0000 @@ -920,7 +920,7 @@ cputime_t utime, stime, cutime, cstime; #ifdef CONFIG_SMP - if (current == next_thread(current)) { + if (thread_group_empty(current)) { /* * Single thread case without the use of any locks. * - 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/