Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752922AbbDHKcH (ORCPT ); Wed, 8 Apr 2015 06:32:07 -0400 Received: from mail2-relais-roc.national.inria.fr ([192.134.164.83]:26761 "EHLO mail2-relais-roc.national.inria.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751300AbbDHKcD (ORCPT ); Wed, 8 Apr 2015 06:32:03 -0400 X-IronPort-AV: E=Sophos;i="5.11,543,1422918000"; d="scan'208";a="132173427" Message-ID: <552503A1.3050502@inria.fr> Date: Wed, 08 Apr 2015 12:32:01 +0200 From: Brice Goglin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.3.0 MIME-Version: 1.0 To: Peter Zijlstra CC: Nishanth Aravamudan , Ingo Molnar , linux-kernel@vger.kernel.org, Srikar Dronamraju , Boqun Feng , Anshuman Khandual , linuxppc-dev@lists.ozlabs.org, Benjamin Herrenschmidt , Anton Blanchard Subject: Re: Topology updates and NUMA-level sched domains References: <20150406214558.GA38501@linux.vnet.ibm.com> <20150407102147.GJ23123@twins.programming.kicks-ass.net> <20150407171410.GA62529@linux.vnet.ibm.com> <20150407194129.GT23123@twins.programming.kicks-ass.net> In-Reply-To: <20150407194129.GT23123@twins.programming.kicks-ass.net> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 729 Lines: 19 Le 07/04/2015 21:41, Peter Zijlstra a ?crit : > No, that's very much not the same. Even if it were dealing with hotplug > it would still assume the cpu to return to the same node. > > But mostly people do not even bother to handle hotplug. > You said userspace assumes the cpu<->node relation is a boot-time fixed one, and hotplug breaks this. How do you expect userspace to handle hotplug? Is there a convenient way to be notified when a CPU (or memory) is unplugged? thanks Brice -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/