From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: Re: [RFC] Asynchronous scsi scanning Date: Thu, 11 May 2006 12:56:02 -0600 Message-ID: <20060511185602.GL12272@parisc-linux.org> References: <20060511143352.GI12272@parisc-linux.org> <44637F4C.3070102@cs.wisc.edu> <20060511182119.GK12272@parisc-linux.org> <44638736.70708@cs.wisc.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from palinux.external.hp.com ([192.25.206.14]:37095 "EHLO palinux.external.hp.com") by vger.kernel.org with ESMTP id S1750705AbWEKS4D (ORCPT ); Thu, 11 May 2006 14:56:03 -0400 Content-Disposition: inline In-Reply-To: <44638736.70708@cs.wisc.edu> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Mike Christie Cc: linux-scsi@vger.kernel.org On Thu, May 11, 2006 at 01:49:26PM -0500, Mike Christie wrote: > > 2) Unless it's serialised (in which case it still takes two hours to > > boot), you lose drive numbering. > > Drive numbering refers to the bus, target numbering right? No, I mean sda, sdb, sdc, etc. > Currently > when you scan a host you are serialized at the host level because of the > host->scan_mutex aren't we? So for each host addition hotplug event you > can scan that host with the command above, and then you can scan all > your hosts in parallel and the drive numbering is not affected is it? I > thought, your patch is basically creating a kernel thread and running > scan host selected, which grabs the scan_mutex, with all wild cards. > What I suggested ends up calling scan host selected with all wild cards > but from userspace. The trick is to avoid adding the sdevs to sysfs until all prior sdevs have been added. I don't see a good way to do that from userspace.