From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752202Ab1IFQou (ORCPT ); Tue, 6 Sep 2011 12:44:50 -0400 Received: from tx2ehsobe003.messaging.microsoft.com ([65.55.88.13]:53931 "EHLO TX2EHSOBE005.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751602Ab1IFQoo (ORCPT ); Tue, 6 Sep 2011 12:44:44 -0400 X-SpamScore: -17 X-BigFish: VPS-17(zz154dM1432N98dK4015Lzz1202hzz8275dhz32i668h839h944h61h) X-Spam-TCS-SCL: 0:0 X-Forefront-Antispam-Report: CIP:163.181.249.108;KIP:(null);UIP:(null);IPVD:NLI;H:ausb3twp01.amd.com;RD:none;EFVD:NLI X-WSS-ID: 0LR416B-01-VPM-02 X-M-MSG: Date: Tue, 6 Sep 2011 18:43:37 +0200 From: Robert Richter To: Don Zickus CC: "x86@kernel.org" , Andi Kleen , Peter Zijlstra , "ying.huang@intel.com" , LKML , "paulmck@linux.vnet.ibm.com" Subject: Re: [V3][PATCH 0/6] x86, nmi: new NMI handling routines Message-ID: <20110906164337.GK14200@erda.amd.com> References: <1314290748-23569-1-git-send-email-dzickus@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1314290748-23569-1-git-send-email-dzickus@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-OriginatorOrg: amd.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 25.08.11 12:45:42, Don Zickus wrote: > I had the pleasure of hosting Robert Richter this week at Red Hat. One of > the issues he wanted to talk with me about was having the NMI handling > routines execute all the NMI handlers for each NMI mainly for his AMD IBS > work. But he also brought up another good point that because of the way NMIs > work, it is possible to lose them if multiple NMIs happen at the same time. > > As a result, we sat around and discussed how we could go about executing > all the nmi handlers for each NMI to ensure that we would not lose any events. > > We decided the best way to do this would be to have the NMI handlers break > away from the notifier routines and create our own. This would allow us to > execute all the handlers without hacking up the notifier stuff and easily > track the number of events processed at a higher level to deal with the new > problemm of extra NMIs. > > I spent some time hacking and came up with this patch. I tested it on my > core2quad machine trying to enable all the NMI handler I could, mainly > perf and kgdb (and oprofile too when perf was disabled). Everything seems > to work correctly. If people are ok with this approach, I'll try and test > this on more machines. > > More details about the patch are in the individual changelogs. Don, thanks for this patch set. So far it looks good to me. See my comments posted. I don't think they require necessarily a new patch version. Instead we could implement changes on top of it. I will rebase my current perf ibs implementation on to of this patches. It would be good to have the patches in tip after kernel.org is back again. Thanks, -Robert -- Advanced Micro Devices, Inc. Operating System Research Center