From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264919AbUGZGTm (ORCPT ); Mon, 26 Jul 2004 02:19:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264922AbUGZGTm (ORCPT ); Mon, 26 Jul 2004 02:19:42 -0400 Received: from moutng.kundenserver.de ([212.227.126.177]:21475 "EHLO moutng.kundenserver.de") by vger.kernel.org with ESMTP id S264919AbUGZGTj (ORCPT ); Mon, 26 Jul 2004 02:19:39 -0400 From: Christian Borntraeger To: linux-kernel@vger.kernel.org Subject: Re: [PATCH] Limit number of concurrent hotplug processes Date: Mon, 26 Jul 2004 08:19:36 +0200 User-Agent: KMail/1.6.2 Cc: Andrew Morton , Hannes Reinecke , linux-hotplug-devel@lists.sourceforge.net References: <40FD23A8.6090409@suse.de> <20040725182006.6c6a36df.akpm@osdl.org> In-Reply-To: <20040725182006.6c6a36df.akpm@osdl.org> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200407260819.36739.linux-kernel@borntraeger.net> X-Provags-ID: kundenserver.de abuse@kundenserver.de auth:5a8b66f42810086ecd21595c2d6103b9 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton wrote: > Hannes Reinecke wrote: > > the attached patch limits the number of concurrent hotplug processes. > hm, it's a bit sad that this happens. Are you able to tell us more about > what is causing such an explosion of module probes? I dont know exactly which scenario Hannes has seen, but its quite simple to trigger this scenario with almost any s390/zSeries. Using the Hardware Management Console or z/VM you are able to hotplug (deactive/activate/attach/detach) almost every channel path. As a channel path can connect a big bunch of devices lots of machine checks are triggered, which causes lots of hotplugs. The same amount of machine checks could happen if a hardware failure happens. Some month ago I played around with a diet version of hotplug. This program was fast and small enough to make my scenario work properly. Nevertheless, as hannes already stated this will only delay the problem. cheers Christian