From owner-freebsd-scsi@FreeBSD.ORG Fri Feb 16 16:32:47 2007 Return-Path: X-Original-To: freebsd-scsi@freebsd.org Delivered-To: freebsd-scsi@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 457A216A408; Fri, 16 Feb 2007 16:32:47 +0000 (UTC) (envelope-from mjacob@freebsd.org) Received: from ns1.feral.com (ns1.feral.com [192.67.166.1]) by mx1.freebsd.org (Postfix) with ESMTP id 19B6D13C4AC; Fri, 16 Feb 2007 16:32:46 +0000 (UTC) (envelope-from mjacob@freebsd.org) Received: from ns1.feral.com (localhost [127.0.0.1]) by ns1.feral.com (8.13.8/8.13.8) with ESMTP id l1GGWcq3017283; Fri, 16 Feb 2007 08:32:46 -0800 (PST) (envelope-from mjacob@freebsd.org) Received: from localhost (mjacob@localhost) by ns1.feral.com (8.13.8/8.13.8/Submit) with ESMTP id l1GGWcYd017280; Fri, 16 Feb 2007 08:32:38 -0800 (PST) (envelope-from mjacob@freebsd.org) X-Authentication-Warning: ns1.feral.com: mjacob owned process doing -bs Date: Fri, 16 Feb 2007 08:32:38 -0800 (PST) From: mjacob@freebsd.org To: Scott Long In-Reply-To: <45D535E4.60609@samsco.org> Message-ID: <20070216083124.Q17178@ns1.feral.com> References: <20070104225519.Q92958@ns1.feral.com> <459E8AE7.90104@samsco.org> <20070105093930.Y34456@ns1.feral.com> <459E97E6.4000603@samsco.org> <459E989C.2020602@samsco.org> <20070105103431.A34456@ns1.feral.com> <20070105104021.D34456@ns1.feral.com> <45A9225D.4080907@scsiguy.com> <20070215145657.N45611@ns1.feral.com> <45D4F7C8.7050903@samsco.org> <20070215175554.X56445@ns1.feral.com> <45D535E4.60609@samsco.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: freebsd-scsi@freebsd.org, mjacob@freebsd.org Subject: Re: CAM rescanner thread? X-BeenThere: freebsd-scsi@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: mjacob@freebsd.org List-Id: SCSI subsystem List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 16 Feb 2007 16:32:47 -0000 > The goal was to create sys/cam/scsi/scsi_probe.c and start divorcing the > SCSI knowledge from the XPT. Having it be a thread was just a side > effect. Unfortunately, I haven't been able to finish that work yet. > It's getting closer, though. But seriously, I saw little specific > benefit to it being a separate thread rather than part of the camisr. > Scanning/probing doesn't block, so it's not like it's blocking the > camisr from processing other I/O. It's just nice from a modularity > standpoint. You can do mallocs. It's true that scanning/probing doesn't block, but it really has to be started from process context. I see an advantage in it as a response to initiating a rescan from Fibre Channel events. It makes the multipath stuff work usefully. D'ya mind if I put it in as an interim?