From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030183AbWGYWP4 (ORCPT ); Tue, 25 Jul 2006 18:15:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030185AbWGYWP4 (ORCPT ); Tue, 25 Jul 2006 18:15:56 -0400 Received: from anchor-post-34.mail.demon.net ([194.217.242.92]:23055 "EHLO anchor-post-34.mail.demon.net") by vger.kernel.org with ESMTP id S1030183AbWGYWPz (ORCPT ); Tue, 25 Jul 2006 18:15:55 -0400 Message-ID: <44C69819.8080908@superbug.co.uk> Date: Tue, 25 Jul 2006 23:15:53 +0100 From: James Courtier-Dutton User-Agent: Thunderbird 1.5.0.4 (X11/20060609) MIME-Version: 1.0 To: Greg KH CC: linux-kernel@vger.kernel.org, greg@kroah.com Subject: Re: [RFC PATCH] Multi-threaded device probing References: <20060725203028.GA1270@kroah.com> In-Reply-To: <20060725203028.GA1270@kroah.com> X-Enigmail-Version: 0.94.0.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Greg KH wrote: > During the kernel summit, I was reminded by the wish by some people to > do device probing in parallel, so I created the following patch. It > offers up the ability for the driver core to create a new thread for > every driver<->device probe call. To enable this, the driver needs to > have the multithread_probe flag set to 1, otherwise the "traditional" > sequencial probe happens. > > Note that this patch does not actually enable the threaded probe for any > busses, as that's very dangerous at this point in time, without the > different bus authors trying it out and verifying that it does work > properly. > > I did enable this for both USB and PCI and shaved .4 seconds off of the > boot time of my tiny little single processor laptop. The savings of my > 4-way workstation is much greater, but things start to happen so fast we > miss the root disk, as init starts before the disks are finished being > initialized. I have some hacks to work around this right now, but I'll > hold off on posting them before I make sure they work properly (breaking > booting of people's machines isn't the best way to get them to accept > new features...) > > Anyway, have fun playing around with this if you want, I'll be adding > this to the next -mm, but you will have to enable the bit on your own if > you want to see any speedups. > > thanks, > > greg k-h > What happens about the logging? Surely one would want the output from one probe to be output into the log as a block, and not mix the output from multiple simultaneous probes. James