Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262193AbVC2IOC (ORCPT ); Tue, 29 Mar 2005 03:14:02 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262199AbVC2INb (ORCPT ); Tue, 29 Mar 2005 03:13:31 -0500 Received: from ecfrec.frec.bull.fr ([129.183.4.8]:56800 "EHLO ecfrec.frec.bull.fr") by vger.kernel.org with ESMTP id S262197AbVC2IFP (ORCPT ); Tue, 29 Mar 2005 03:05:15 -0500 Subject: Re: [patch 1/2] fork_connector: add a fork connector From: Guillaume Thouvenin To: Paul Jackson Cc: Andrew Morton , Greg KH , lkml , Evgeniy Polyakov , Jay Lan , Erich Focht , Ram , Gerrit Huizenga , elsa-devel , dean gaudet In-Reply-To: <20050328134242.4c6f7583.pj@engr.sgi.com> References: <1111745010.684.49.camel@frecb000711.frec.bull.fr> <20050328134242.4c6f7583.pj@engr.sgi.com> Date: Tue, 29 Mar 2005 10:05:03 +0200 Message-Id: <1112083503.20919.23.camel@frecb000711.frec.bull.fr> Mime-Version: 1.0 X-Mailer: Evolution 2.0.3 X-MIMETrack: Itemize by SMTP Server on ECN002/FR/BULL(Release 5.0.12 |February 13, 2003) at 29/03/2005 10:14:43, Serialize by Router on ECN002/FR/BULL(Release 5.0.12 |February 13, 2003) at 29/03/2005 10:14:48, Serialize complete at 29/03/2005 10:14:48 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: 1392 Lines: 34 On Mon, 2005-03-28 at 13:42 -0800, Paul Jackson wrote: > Guillaume wrote: > > The lmbench shows that the overhead (the construction and the sending > > of the message) in the fork() routine is around 7%. > > Thanks for including the numbers. The 7% seems a bit costly, for a bit > more accounting information. Perhaps dean's suggestion, to not use > ascii, will help. I hope so, though I doubt it will make a huge > difference. Was this 7% loss with or without a user level program > consuming the sent messages? I would think that the number of interest > would include a minimal consumer task. Yes, dean's suggestion helps. The overhead is now around 4% fork_connector disabled: Process fork+exit: 149.4444 microseconds fork_connector enabled: Process fork+exit: 154.9167 microseconds > Having the "#ifdef CONFIG_FORK_CONNECTOR" chunk of code right in fork.c > seems unfortunate. Can the real fork_connector() be put elsewhere, and > the ifdef put in a header file that makes it a no-op if not configured, > or simply a function declaration, if configured? I think that it can be moved in include/linux/connector.h 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/