Return-Path: Received: from mail-yb0-f176.google.com ([209.85.213.176]:34188 "EHLO mail-yb0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751696AbcKHW6w (ORCPT ); Tue, 8 Nov 2016 17:58:52 -0500 Date: Tue, 8 Nov 2016 17:52:21 -0500 From: Tejun Heo To: "J. Bruce Fields" Cc: Bhaktipriya Shridhar , Jeff Layton , linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] fs/nfsd/nfs4callback: Remove deprecated create_singlethread_workqueue Message-ID: <20161108225221.GB6460@htj.duckdns.org> References: <20160830205348.GA31915@Karyakshetra> <20161108213911.GA27681@fieldses.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20161108213911.GA27681@fieldses.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: Hello, Bruce. On Tue, Nov 08, 2016 at 04:39:11PM -0500, J. Bruce Fields wrote: > Apologies, just cleaning out old mail and finding some I should have > responded to long ago: > > On Wed, Aug 31, 2016 at 02:23:48AM +0530, Bhaktipriya Shridhar wrote: > > The workqueue "callback_wq" queues a single work item &cb->cb_work per > > nfsd4_callback instance and thus, it doesn't require execution ordering. > > What's "execution ordering"? > > We definitely do depend on the fact that at most one of these is running > at a time. If there can be multiple cb's and thus cb->cb_work's per callback_wq, it'd need explicit ordering. Is that the case? Thanks. -- tejun