From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail2-relais-roc.national.inria.fr (mail2-relais-roc.national.inria.fr [192.134.164.83]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 6220D1A051A for ; Wed, 8 Apr 2015 20:42:48 +1000 (AEST) Message-ID: <552503A1.3050502@inria.fr> Date: Wed, 08 Apr 2015 12:32:01 +0200 From: Brice Goglin MIME-Version: 1.0 To: Peter Zijlstra 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 Cc: Boqun Feng , Srikar Dronamraju , Nishanth Aravamudan , linux-kernel@vger.kernel.org, Ingo Molnar , Anton Blanchard , linuxppc-dev@lists.ozlabs.org, Anshuman Khandual List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Le 07/04/2015 21:41, Peter Zijlstra a écrit : > 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