From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965656AbXDCR1k (ORCPT ); Tue, 3 Apr 2007 13:27:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965959AbXDCR1k (ORCPT ); Tue, 3 Apr 2007 13:27:40 -0400 Received: from one.firstfloor.org ([213.235.205.2]:54774 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965656AbXDCR1j (ORCPT ); Tue, 3 Apr 2007 13:27:39 -0400 Date: Tue, 3 Apr 2007 19:27:36 +0200 From: Andi Kleen To: Ulrich Drepper Cc: Andi Kleen , Linux Kernel , Andrew Morton Subject: Re: getting processor numbers Message-ID: <20070403172736.GA23689@one.firstfloor.org> References: <461286D6.2040407@redhat.com> <46128C1B.1090900@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <46128C1B.1090900@redhat.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 03, 2007 at 10:17:15AM -0700, Ulrich Drepper wrote: > Andi Kleen wrote: > > There was a proposal some time ago to put that into the ELF aux vector > > Unfortunately there was disagreement on what information to put > > there exactly (full topology, only limited numbers etc.) > > Topology, yes, I'm likely in favor of it. What topology and what use case? > Processor number: no. Unless you want to rip out hotpluging. I'm Topology is dependent on the number of CPUs. Hot plugging is a completely orthogonal problem. Even your original proposal wouldn't address it. Mine doesn't neither, because i suspect most programs won't care. If it's addressed it could work on top of it. The aux vector to get the information quickly at program startup and later updates can get it from /sys. If some program starts caring we would need to implement some notification mechanism (that would be possible), but it might be hard to fit into glibc because you don't have a event loop. -Andi