From owner-svn-src-all@FreeBSD.ORG Fri May 22 13:44:24 2009 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EDA1F106566C; Fri, 22 May 2009 13:44:24 +0000 (UTC) (envelope-from scottl@samsco.org) Received: from pooker.samsco.org (pooker.samsco.org [168.103.85.57]) by mx1.freebsd.org (Postfix) with ESMTP id 999B58FC19; Fri, 22 May 2009 13:44:24 +0000 (UTC) (envelope-from scottl@samsco.org) Received: from phobos.local (pooker.samsco.org [168.103.85.57]) by pooker.samsco.org (8.14.2/8.14.2) with ESMTP id n4MDiIHp086477; Fri, 22 May 2009 07:44:19 -0600 (MDT) (envelope-from scottl@samsco.org) Message-ID: <4A16AC32.2040507@samsco.org> Date: Fri, 22 May 2009 07:44:18 -0600 From: Scott Long User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en-US; rv:1.8.1.13) Gecko/20080313 SeaMonkey/1.1.9 MIME-Version: 1.0 To: John Baldwin References: <3bbf2fe10905210629p46c7a204v6863aaba77354462@mail.gmail.com> <20090521194243.GW1927@deviant.kiev.zoral.com.ua> <3bbf2fe10905211511g53defb6cmac45fc2469cc64f@mail.gmail.com> <200905220921.34785.jhb@freebsd.org> In-Reply-To: <200905220921.34785.jhb@freebsd.org> X-Enigmail-Version: 0.95.6 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-4.5 required=3.8 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.1.8 X-Spam-Checker-Version: SpamAssassin 3.1.8 (2007-02-13) on pooker.samsco.org Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, Attilio Rao , svn-src-head@freebsd.org, rwatson@freebsd.org, Kostik Belousov , "M. Warner Losh" Subject: Re: svn commit: r192535 - head/sys/kern X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 22 May 2009 13:44:25 -0000 John Baldwin wrote: > On Thursday 21 May 2009 6:11:02 pm Attilio Rao wrote: >> At this point I wonder what's the purpose of maintaining the sleeping >> version for such functions? > > Actually, I still very much do not like using M_NOWAIT needlessly. I would > much rather the solution for make_dev() be that the 1 or 2 places that need > to do it with a mutex held instead queue a task to do the actual make_dev() > in a taskqueue when no locks are held. This is basically what > destroy_dev_sched() is doing. Perhaps a make_dev_sched() with a similar > callback to be called on completion would be better. Having a device driver > do all the work to setup the hardware only to fail to create a node in /dev > so that userland can actually use it is pretty rediculous and useless. > It's a lot easier for me to handle a failure of make_dev in CAM than it is to decouple the call to it. Please don't dictate policy. Scott