From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261605AbUDSRYV (ORCPT ); Mon, 19 Apr 2004 13:24:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261615AbUDSRYV (ORCPT ); Mon, 19 Apr 2004 13:24:21 -0400 Received: from mtaw6.prodigy.net ([64.164.98.56]:36815 "EHLO mtaw6.prodigy.net") by vger.kernel.org with ESMTP id S261605AbUDSRYQ (ORCPT ); Mon, 19 Apr 2004 13:24:16 -0400 Message-ID: <40840B7E.4080605@pacbell.net> Date: Mon, 19 Apr 2004 10:25:18 -0700 From: David Brownell User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.2.1) Gecko/20030225 X-Accept-Language: en-us, en, fr MIME-Version: 1.0 To: Duncan Sands CC: Greg KH , linux-usb-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, Frederic Detienne Subject: Re: [linux-usb-devel] [PATCH 1/9] USB usbfs: take a reference to the usb device References: <200404141229.26677.baldrick@free.fr> <200404172217.10994.baldrick@free.fr> In-Reply-To: <200404172217.10994.baldrick@free.fr> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Heh ... I like this, getting rid of more of locks from usbcore. Duncan Sands wrote: > In later steps we can > (1) turn dev->serialize into a rwsem That doesn't bother me (unlike some folk!) but I do agree it should wait until the rest shakes out, and until we can observe benefits. Hardly any code paths need complete mutual exclusion (writelock). > (2) push the acquisition of dev->serialize down to the lower levels as they are fixed up. Actually at least some of those lower levels are getting fixed by pushing the lock acquisition up. The reason usbfs needs to get involved in that stuff is that it's going around the standard usb driver structure. One of the other things that "usbfs2" should do is act a lot more like a "normal" device driver, so it plays better with more of the normal usbcore mechanisms. - Dave