From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH] serialize bus scanning Date: Wed, 27 Aug 2003 22:35:44 +0200 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <20030827203544.GA27020@lst.de> References: <20030825122416.GE15506@lst.de> <20030827202908.GB7852@krispykreme> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from verein.lst.de ([212.34.189.10]:24771 "EHLO mail.lst.de") by vger.kernel.org with ESMTP id S262312AbTH0Ufu (ORCPT ); Wed, 27 Aug 2003 16:35:50 -0400 Content-Disposition: inline In-Reply-To: <20030827202908.GB7852@krispykreme> List-Id: linux-scsi@vger.kernel.org To: Anton Blanchard Cc: James Bottomley , linux-scsi@vger.kernel.org On Thu, Aug 28, 2003 at 06:29:08AM +1000, Anton Blanchard wrote: > > Hi, > > > Synchronize all scanning activity, this fixes long-standing races > > vs /proc/scsi/scsi and sysfs addition and deletion of devices. > > > > Note that this does not serialize removing, the lists will get > > their own locking soon. > > Ive started playing with parallel probe in the lab (on some large ppc64 > boxes). I know we have a lot of work to do before this will all work, > but would it be possible to make this semaphore per host? you can just add a per-host mutex and lock it in the same places as indicated by the comment in the patch. > Even with a per host semaphore, it annoys me how long it takes to spin > up 7 disks especially if a few of them are dead. Longer term are we > planning to overlap spinup of disks on the same host? I have no plans to do that but if someone comes up with a proper patch that would be nice.