From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752982AbbDADFP (ORCPT ); Tue, 31 Mar 2015 23:05:15 -0400 Received: from mail-qc0-f174.google.com ([209.85.216.174]:35750 "EHLO mail-qc0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751271AbbDADFM (ORCPT ); Tue, 31 Mar 2015 23:05:12 -0400 Date: Tue, 31 Mar 2015 23:05:09 -0400 From: Tejun Heo To: Kamezawa Hiroyuki Cc: Gu Zheng , linux-kernel@vger.kernel.org, laijs@cn.fujitsu.com, isimatu.yasuaki@jp.fujitsu.com, tangchen@cn.fujitsu.com, izumi.taku@jp.fujitsu.com Subject: Re: [PATCH 0/2] workqueue: fix a bug when numa mapping is changed Message-ID: <20150401030509.GM9974@htj.duckdns.org> References: <1427336275-32066-1-git-send-email-guz.fnst@cn.fujitsu.com> <55137935.5080301@jp.fujitsu.com> <55139340.8070201@cn.fujitsu.com> <20150326151850.GD1953@htj.duckdns.org> <551436F2.5020804@jp.fujitsu.com> <55191C3D.8070800@cn.fujitsu.com> <551A3A01.7030707@jp.fujitsu.com> <20150331152822.GE9974@htj.duckdns.org> <551B5E0F.1020302@jp.fujitsu.com> <20150401030242.GL9974@htj.duckdns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150401030242.GL9974@htj.duckdns.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 31, 2015 at 11:02:42PM -0400, Tejun Heo wrote: > Ugh... so, cpu number allocation on hot-add is part of userland > interface that we're locked into? Tying hotplug and id allocation > order together usually isn't a good idea. What if the cpu up fails > while running the notifiers? The ID is already allocated and the next > cpu being brought up will be after a hole anyway. Is this even > actually gonna affect userland? At any rate, this isn't big a deal. If the mapping has to be dynamic, it'd be great to move the mapping code from workqueue to cpu hotplug proper tho. Thanks. -- tejun