Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261286AbVC3FkP (ORCPT ); Wed, 30 Mar 2005 00:40:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261271AbVC3FkO (ORCPT ); Wed, 30 Mar 2005 00:40:14 -0500 Received: from ecfrec.frec.bull.fr ([129.183.4.8]:39405 "EHLO ecfrec.frec.bull.fr") by vger.kernel.org with ESMTP id S261289AbVC3Fj4 (ORCPT ); Wed, 30 Mar 2005 00:39:56 -0500 Subject: Re: [patch 1/2] fork_connector: add a fork connector From: Guillaume Thouvenin To: Paul Jackson Cc: Evgeniy Polyakov , Andrew Morton , Greg KH , lkml , Jay Lan , Erich Focht , Ram , Gerrit Huizenga , elsa-devel In-Reply-To: <20050329072335.52b06462.pj@engr.sgi.com> References: <1111745010.684.49.camel@frecb000711.frec.bull.fr> <20050328134242.4c6f7583.pj@engr.sgi.com> <1112079856.5243.24.camel@uganda> <20050329004915.27cd0edf.pj@engr.sgi.com> <1112087822.8426.46.camel@frecb000711.frec.bull.fr> <20050329072335.52b06462.pj@engr.sgi.com> Date: Wed, 30 Mar 2005 07:39:43 +0200 Message-Id: <1112161183.20919.84.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 30/03/2005 07:49:29, Serialize by Router on ECN002/FR/BULL(Release 5.0.12 |February 13, 2003) at 30/03/2005 07:49:32, Serialize complete at 30/03/2005 07:49:32 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: 1686 Lines: 35 On Tue, 2005-03-29 at 07:23 -0800, Paul Jackson wrote: > Guillaume wrote: > > The goal of the fork connector is to inform a user space application > > that a fork occurs in the kernel. This information (cpu ID, parent PID > > and child PID) can be used by several user space applications. It's not > > only for accounting. Accounting and fork_connector are two different > > things and thus, fork_connector doesn't do the merge of any kinds of > > data (and it will never do). > > Yes - it is clear that the fork_connector does this - inform user space > of fork information . I'm not saying that > fork_connector should merge data; I'm observing that it doesn't, and > that this would seem to serve the needs of accounting poorly. > > Out of curiosity, what are these 'several user space applications?' The > only one I know of is this extension to bsd accounting to include > capturing parent and child pid at fork. Probably you've mentioned some > other uses of fork_connector before here, but I missed it. During the discussion some people like Erich Focht and Ram mentioned that this information can be useful for them. I remember that Erich had in mind something like cluster-wide pid tracking in user space. When I wrote "several user space applications" it was just to say that this fork connector is not designed only for ELSA and fork information is available to every listeners. Regards, 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/