Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261880AbVCHIqA (ORCPT ); Tue, 8 Mar 2005 03:46:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261888AbVCHIqA (ORCPT ); Tue, 8 Mar 2005 03:46:00 -0500 Received: from ecfrec.frec.bull.fr ([129.183.4.8]:9859 "EHLO ecfrec.frec.bull.fr") by vger.kernel.org with ESMTP id S261880AbVCHIpw (ORCPT ); Tue, 8 Mar 2005 03:45:52 -0500 Subject: Re: [PATCH 2.6.11-rc4-mm1] connector: Add a fork connector From: Guillaume Thouvenin To: Andrew Morton Cc: lkml , Evgeniy Polyakov , elsa-devel , Jay Lan , Gerrit Huizenga , Erich Focht , Kaigai Kohei In-Reply-To: <1110266972.10433.27.camel@frecb000711.frec.bull.fr> References: <1109240677.1738.196.camel@frecb000711.frec.bull.fr> <1110266972.10433.27.camel@frecb000711.frec.bull.fr> Date: Tue, 08 Mar 2005 09:45:51 +0100 Message-Id: <1110271551.10590.41.camel@frecb000711.frec.bull.fr> Mime-Version: 1.0 X-Mailer: Evolution 2.0.2 X-MIMETrack: Itemize by SMTP Server on ECN002/FR/BULL(Release 5.0.12 |February 13, 2003) at 08/03/2005 09:54:58, Serialize by Router on ECN002/FR/BULL(Release 5.0.12 |February 13, 2003) at 08/03/2005 09:55:01, Serialize complete at 08/03/2005 09:55:01 Content-Transfer-Encoding: 7bit Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1365 Lines: 38 On Tue, 2005-03-08 at 08:29 +0100, Guillaume Thouvenin wrote: > TODO: > - Run the lmbench with the user space application that manages > group of processus. if fork connector is not used the only > overhead is a test in the do_fork() routine. For information here are some results when using the process creation tests "lat_proc fork". Test was run ten times thus the average is computed with the ten metrics. with a kernel 2.6.11-rc4-mm1 max value = 164.0588 msec min value = 159.8571 msec average = 161.7012 msec with a kernel 2.6.11-rc4-mm1 and the cnfork (cn_fork_enable == 0) max value = 163.3438 msec min value = 159.8857 msec average = 160.9447 msec with a kernel 2.6.11-rc4-mm1 and the cnfork (cn_fork_enable == 1) max value = 177.6885 msec min value = 170.9057 msec average = 173.7675 msec So we see that when the fork connector is disable the time it takes to split a process into two copies is the same (and it's normal) and when the fork connector is enable, it's around 7.5% slower. Best, Guillaume - 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/