From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757861AbcG0SAx (ORCPT ); Wed, 27 Jul 2016 14:00:53 -0400 Received: from mail-yw0-f194.google.com ([209.85.161.194]:34371 "EHLO mail-yw0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753179AbcG0SAv (ORCPT ); Wed, 27 Jul 2016 14:00:51 -0400 Date: Wed, 27 Jul 2016 14:00:47 -0400 From: Tejun Heo To: Oliver Neukum Cc: Bhaktipriya Shridhar , Geliang Tang , "GeyslanG.Bem@Karyakshetra" , Masanari Iida , Greg Kroah-Hartman , Michal Hocko , Vlastimil Babka , Mel Gorman , Saurabh Karajgaonkar , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Subject: Re: [RFC] usb: host: u132-hcd: Remove deprecated create_singlethread_workqueue Message-ID: <20160727180047.GJ4144@mtj.duckdns.org> References: <20160727092043.GA25086@Karyakshetra> <1469611796.2408.4.camel@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1469611796.2408.4.camel@suse.com> User-Agent: Mutt/1.6.1 (2016-04-27) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Oliver. On Wed, Jul 27, 2016 at 11:29:56AM +0200, Oliver Neukum wrote: > On Wed, 2016-07-27 at 14:50 +0530, Bhaktipriya Shridhar wrote: > > The workqueue "workqueue" has multiple workitems which may require > > ordering. Hence, a dedicated ordered workqueue has been used. > > Since the workqueue is not being used on a memory reclaim path, > > WQ_MEM_RECLAIM has not been set. > > That is incorrect. The work queue is used by the HCD to handle > TDs, which are parts of basic IO. The HCD in turn is used by > usb-storage and uas, which are block drivers and those are obviously > used on the memory reclaim path. Hmm... I didn't know the whole USB stack could operate without allocating memory. Does usb stack have mempools and stuff all the way through? Thanks. -- tejun