From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751807Ab3IRHdj (ORCPT ); Wed, 18 Sep 2013 03:33:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60208 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751369Ab3IRHdh (ORCPT ); Wed, 18 Sep 2013 03:33:37 -0400 Message-ID: <1379489584.12907.11.camel@nilsson.home.kraxel.org> Subject: Re: [PATCH v3 3/6] uas: make work list per-device From: Gerd Hoffmann To: Christoph Hellwig Cc: linux-usb@vger.kernel.org, Matthew Wilcox , Sarah Sharp , Matthew Dharm , Greg Kroah-Hartman , "open list:USB ATTACHED SCSI" , "open list:USB MASS STORAGE..." , open list Date: Wed, 18 Sep 2013 09:33:04 +0200 In-Reply-To: <20130917203012.GA1752@infradead.org> References: <1379071635-30701-1-git-send-email-kraxel@redhat.com> <1379071635-30701-4-git-send-email-kraxel@redhat.com> <20130917203012.GA1752@infradead.org> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Di, 2013-09-17 at 13:30 -0700, Christoph Hellwig wrote: > On Fri, Sep 13, 2013 at 01:27:12PM +0200, Gerd Hoffmann wrote: > > Simplifies locking, we'll protect the list with the device spin lock. > > Also plugs races which can happen when two devices operate on the > > global list. > > > > While being at it rename the list head from "list" to "work", preparing > > for the addition of a second list. > > Why do you even the list? The list was already there when I took over maintainance ... > What would a ordered per-device workqueue not > provide? Had no reason to look into replacing the list with something else so far. Why do you suggest using a workqueue instead? Note that the list is not used in a typical request workflow. Only in case queuing an usb urb failed the request is linked into the list and the worker will try to submit the usb urb again. cheers, Gerd