From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756482Ab0KWTSI (ORCPT ); Tue, 23 Nov 2010 14:18:08 -0500 Received: from mail-ew0-f46.google.com ([209.85.215.46]:60470 "EHLO mail-ew0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756425Ab0KWTSG (ORCPT ); Tue, 23 Nov 2010 14:18:06 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:mime-version:content-type :content-disposition:user-agent; b=GOQyJjHcAHBDGECUqyKvoFgBYB1BWRd1gV5fHmTsnel1QAo57PyNkouWXFKQxS48bT O1rHi8IW1sLma9v4QlT+6HcvX1CiNsTLy+bc8IhL36EH7w2oHHqHeww7l+EBT7nUDtDa PmcFR9CgPUkR6H26SB7OSLidBQQipg0+D74WY= Date: Tue, 23 Nov 2010 22:18:01 +0300 From: Cyrill Gorcunov To: Peter Zijlstra Cc: Don Zickus , sedat.dilek@gmail.com, LKML , Ingo Molnar Subject: Re: [PATCH] x86, perf, nmi: Disable perf if counters are not accessable Message-ID: <20101123191801.GD5997@lenovo> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 23, 2010 at 08:07:47PM +0100, Peter Zijlstra wrote: > On Tue, 2010-11-23 at 22:04 +0300, Cyrill Gorcunov wrote: > > On Tue, Nov 23, 2010 at 07:27:07PM +0100, Peter Zijlstra wrote: > > > On Tue, 2010-11-23 at 19:21 +0100, Sedat Dilek wrote: > > > > Due to BIOS l(ocal)apic is not possible: > > > > > > > > # dmesg | grep -i apic > > > > [ 0.000000] Using APIC driver default > > > > [ 0.000000] Local APIC disabled by BIOS -- you can enable it with "lapic" > > > > [ 0.000000] APIC: disable apic facility > > > > [ 0.000000] APIC: switched to apic NOOP > > > > [ 0.008891] no APIC, boot with the "lapic" boot parameter to force-enable it. > > > > [ 0.036141] Local APIC not detected. Using dummy APIC emulation. > > > > > > Have you tried booting with "lapic" as the second last msg suggests you > > > do? > > > > Peter, Don, might not we need something like the patch below -- ie to check for > > apic earlier and do not acquire cpu for PERF cpu bit, and its cpu model, etc > > if there is no active apic? And perhaps for nmi-watchdog, we should not try > > to creat perf event for same reason and simply report that nmi-watchdog is > > disabled (though of course hpet based one should try to continue). > > > > No? > > > > Ah, no.. now I get what you mean. > > We can use the pmu without interrupt with we miss the lapic, that is > perf-stat will still work. > Yeah, I forgot about perf-stat Cyrill