Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755597Ab2BFUbm (ORCPT ); Mon, 6 Feb 2012 15:31:42 -0500 Received: from casper.infradead.org ([85.118.1.10]:55313 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755536Ab2BFUbj (ORCPT ); Mon, 6 Feb 2012 15:31:39 -0500 Subject: Re: [BUG] perf: perf sched warning possibly due to clock granularity on AMD From: Peter Zijlstra To: Borislav Petkov Cc: Stephane Eranian , linux-kernel@vger.kernel.org, acme@redhat.com, mingo@elte.hu, robert.richter@amd.com, eric.dumazet@gmail.com, Andreas Herrmann , Venkatesh Pallipadi In-Reply-To: <20120206202722.GA556@aftab> References: <20120206132546.GA30854@quad> <1328538403.2482.4.camel@laptop> <20120206153408.GA31237@aftab> <1328546246.2482.10.camel@laptop> <20120206164626.GA31704@aftab> <1328547259.2482.11.camel@laptop> <20120206202722.GA556@aftab> Content-Type: text/plain; charset="UTF-8" Date: Mon, 06 Feb 2012 21:31:33 +0100 Message-ID: <1328560293.2482.24.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.32.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1151 Lines: 26 On Mon, 2012-02-06 at 21:27 +0100, Borislav Petkov wrote: > On Mon, Feb 06, 2012 at 05:54:19PM +0100, Peter Zijlstra wrote: > > On Mon, 2012-02-06 at 17:46 +0100, Borislav Petkov wrote: > > > > across all CPUs in the entire system. > > > > > > Right, by the "entire system" you mean consistent across cores and > > > sockets but not necessarily across cabinets, as in the comment above, > > > correct? > > > > > > If so, let me ask around if this holds true too. > > > > Every CPU available to the kernel. So if you run a single system image > > across your cabinets, then yes those too. > > Ok, but what about that sentence "(but not across cabinets - we turn > it off in that case explicitly.)" - I don't see any place where it is > turned off explicitly... Maybe a stale comment? I suspect it might be the sched_clock_stable = 0 in mark_tsc_unstable(), but lets ask Venki, IIRC he wrote all that. -- 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/