Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752630Ab3FZQLm (ORCPT ); Wed, 26 Jun 2013 12:11:42 -0400 Received: from relay3.sgi.com ([192.48.152.1]:54551 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751380Ab3FZQLl (ORCPT ); Wed, 26 Jun 2013 12:11:41 -0400 Message-ID: <51CB12BC.9080708@sgi.com> Date: Wed, 26 Jun 2013 11:11:40 -0500 From: Nathan Zimmer User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130510 Thunderbird/17.0.6 MIME-Version: 1.0 To: Ingo Molnar CC: Dave Hansen , , , , , , , , , , , , , Linus Torvalds , Peter Zijlstra Subject: Re: [RFC 2/2] x86_64, mm: Reinsert the absent memory References: <1371831934-156971-1-git-send-email-nzimmer@sgi.com> <1371831934-156971-3-git-send-email-nzimmer@sgi.com> <20130623092840.GB13445@gmail.com> <20130624203657.GA107621@asylum.americas.sgi.com> <20130626121430.GA4980@gmail.com> <20130626144903.GA2210@asylum.americas.sgi.com> <51CB04C7.8060702@intel.com> <51CB06BD.8090202@sgi.com> <20130626155835.GC7399@gmail.com> In-Reply-To: <20130626155835.GC7399@gmail.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [128.162.233.140] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1412 Lines: 36 On 06/26/2013 10:58 AM, Ingo Molnar wrote: > * Nathan Zimmer wrote: > >> On 06/26/2013 10:12 AM, Dave Hansen wrote: >>> On 06/26/2013 07:49 AM, Nathan Zimmer wrote: >>>> My guess it is the NMIs overwhelming the system but I have not found a good way >>>> to profile perf gone wild so it is only a guess. >>> I've got an 80-core system and the symptoms sound similar to perf issues >>> I'm seeing. Dropping the sample rate helped for me, and there's a patch >>> in -tip at the moment to do it automatically: >>> >>>> http://git.kernel.org/cgit/linux/kernel/git/tip/tip.git/commit/?id=14c63f17b1fde5a575a28e96547a22b451c71fb5 >>> Looks like you've also found that debugging NMIs is fun. :) >> More fun then one person can handle. >> I'll have to take this patch for a spin. > Please try latest -tip:master, there's a series of patches from Dave that > address this problem category. > > Does it only happen with -g, or with regular perf record and/or with perf > top as well? > > Thanks, > > Ingo It happens in all those cases, but I notice it most when doing a perf record -g -a I'll try the tip series and see how it compares. Thanks Nate -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/