From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757076Ab0JQArV (ORCPT ); Sat, 16 Oct 2010 20:47:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:63704 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757061Ab0JQArU (ORCPT ); Sat, 16 Oct 2010 20:47:20 -0400 Date: Sat, 16 Oct 2010 20:46:41 -0400 From: Don Zickus To: Peter Zijlstra Cc: mingo@redhat.com, hpa@zytor.com, ying.huang@intel.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@elte.hu, linux-tip-commits@vger.kernel.org Subject: Re: [tip:perf/core] x86, NMI: Rewrite NMI handler Message-ID: <20101017004641.GB4140@redhat.com> References: <1287195738-3136-4-git-send-email-dzickus@redhat.com> <1287250157.1998.124.camel@laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1287250157.1998.124.camel@laptop> User-Agent: Mutt/1.5.20 (2009-08-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Oct 16, 2010 at 07:29:17PM +0200, Peter Zijlstra wrote: > On Sat, 2010-10-16 at 16:36 +0000, tip-bot for Huang Ying wrote: > > Commit-ID: e21f3e4957f4a55f546873605a5caa59556bb144 > > Gitweb: http://git.kernel.org/tip/e21f3e4957f4a55f546873605a5caa59556bb144 > > Author: Huang Ying > > AuthorDate: Fri, 15 Oct 2010 22:22:16 -0400 > > Committer: Ingo Molnar > > CommitDate: Sat, 16 Oct 2010 15:01:27 +0200 > > > > x86, NMI: Rewrite NMI handler > > > > The original NMI handler is quite outdated in many aspects. This > > patch tries to fix it. > > > > The order to process the NMI sources are changed as follow: > > > > notify_die(DIE_NMI_IPI); > > notify_die(DIE_NMI); > > /* process io port 0x61 */ > > nmi_watchdog_touch(); > > unknown_nmi(); > > NACK! > > I object to the DIE_NMI_IPI existance.. Hmm, well to his defense, he isn't adding DIE_NMI_IPI. That code is already there. He is just re-arranging it, making it look painfully obvious the die_chain probably isn't as efficient as it should be. I think a bunch of us agree that we need to revamp the NMI notifier to make it less wasteful. I was hoping we could do that in a separate patch that would be layered on top of Huangs. Would you object to at least consider having this patch series in a work-in-progress git branch that we can build on top of, with the final outcome containing an nmi notifier that meets your expectations? Cheers, Don