From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755549Ab1LMSyo (ORCPT ); Tue, 13 Dec 2011 13:54:44 -0500 Received: from casper.infradead.org ([85.118.1.10]:38789 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751750Ab1LMSyn convert rfc822-to-8bit (ORCPT ); Tue, 13 Dec 2011 13:54:43 -0500 Message-ID: <1323802423.9082.21.camel@twins> Subject: Re: [PATCH 2/2] Add a thread cpu time implementation to vDSO From: Peter Zijlstra To: Arun Sharma Cc: Eric Dumazet , linux-kernel@vger.kernel.org, Kumar Sundararajan , Ingo Molnar , Thomas Gleixner , john stultz , Andy Lutomirski Date: Tue, 13 Dec 2011 19:53:43 +0100 In-Reply-To: <4EE7962E.90204@fb.com> References: <1323718578-1157-1-git-send-email-asharma@fb.com> <1323718578-1157-3-git-send-email-asharma@fb.com> <1323720791.2583.23.camel@edumazet-laptop> <4EE66FE9.1050202@fb.com> <1323725243.2583.27.camel@edumazet-laptop> <4EE67CB5.7000404@fb.com> <1323766358.9082.0.camel@twins> <4EE7962E.90204@fb.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT X-Mailer: Evolution 3.2.1- Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2011-12-13 at 10:15 -0800, Arun Sharma wrote: > On 12/13/11 12:52 AM, Peter Zijlstra wrote: > > On Mon, 2011-12-12 at 14:14 -0800, Arun Sharma wrote: > > > >>> But really most modern distros have NR_CPUS> 64 > >> > >> Is 256 the new 64? :) > > > > 4096 in fact. > > Not sure if you're asking for vsyscall support for NR_CPUS=4096 case or > just a compile fix + disabled vsyscall is ok. I'm saying distros tend to compile with NR_CPUS=4096, so if you auto-disable the feature for that, it effectively doesn't exist.