From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764214AbYHFDhP (ORCPT ); Tue, 5 Aug 2008 23:37:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757665AbYHFDhD (ORCPT ); Tue, 5 Aug 2008 23:37:03 -0400 Received: from one.firstfloor.org ([213.235.205.2]:38827 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752580AbYHFDhB (ORCPT ); Tue, 5 Aug 2008 23:37:01 -0400 Date: Wed, 6 Aug 2008 05:37:36 +0200 From: Andi Kleen To: Jeremy Fitzhardinge Cc: Andi Kleen , Ingo Molnar , LKML , x86@kernel.org, Nick Piggin , Jens Axboe Subject: Re: [PATCH 0 of 8] x86/smp function calls: convert x86 tlb flushes to use function calls Message-ID: <20080806033736.GB24801@one.firstfloor.org> References: <87k5eu6d4f.fsf@basil.nowhere.org> <48991B84.2080704@goop.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <48991B84.2080704@goop.org> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 05, 2008 at 08:33:24PM -0700, Jeremy Fitzhardinge wrote: > Andi Kleen wrote: > >Jeremy Fitzhardinge writes: > > > > > >>1. use smp_call_function_mask to implement cross-cpu TLB flushes > >> > > > > > >Do you have any measurements comparing performance of the old and > >the new call? TLB flush is quite time critical so we should be very > >careful here. > > No. What benchmark would you suggest? Micro benchmark. Just stick RDTSC around the calls and trigger a few remote flushes by e.g. doing mmap/munmap on a multithreaded program running on different CPUs. -Andi