From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759069AbYG2Oqu (ORCPT ); Tue, 29 Jul 2008 10:46:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758654AbYG2Oqh (ORCPT ); Tue, 29 Jul 2008 10:46:37 -0400 Received: from gw.goop.org ([64.81.55.164]:48912 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759950AbYG2Oqg (ORCPT ); Tue, 29 Jul 2008 10:46:36 -0400 Message-ID: <488F2D48.7030305@goop.org> Date: Tue, 29 Jul 2008 07:46:32 -0700 From: Jeremy Fitzhardinge User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: Andi Kleen CC: Ingo Molnar , Jens Axboe , Linux Kernel Mailing List Subject: Re: x86: Is there still value in having a special tlb flush IPI vector? References: <488E534F.2030204@goop.org> <488E5455.6010901@goop.org> <20080729021215.GG30344@one.firstfloor.org> <488EB8BE.8050806@goop.org> <20080729120237.GH30344@one.firstfloor.org> In-Reply-To: <20080729120237.GH30344@one.firstfloor.org> X-Enigmail-Version: 0.95.6 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Andi Kleen wrote: >> Yes, but it's only held briefly to put things onto the list. It doesn't >> get held over the whole IPI transaction as the old smp_call_function >> did, and the tlb flush code still does. RCU is used to manage the list >> walk and freeing, so there's no long-held locks there either. >> > > If it bounces regularly it will still hurt. > We could convert smp_call_function_mask to use a multi-vector scheme like tlb_64.c if that turns out to be an issue. J