From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756731Ab2LMOav (ORCPT ); Thu, 13 Dec 2012 09:30:51 -0500 Received: from mail-pa0-f46.google.com ([209.85.220.46]:42708 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756625Ab2LMOas (ORCPT ); Thu, 13 Dec 2012 09:30:48 -0500 Message-ID: <50C9E692.9070506@gmail.com> Date: Thu, 13 Dec 2012 07:30:42 -0700 From: David Ahern User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: Ingo Molnar , Linus Torvalds CC: Linux Kernel Mailing List , Arnaldo Carvalho de Melo , Peter Zijlstra , Thomas Gleixner , Andrew Morton Subject: Re: [GIT PULL] perf changes for v3.8 References: <20121211090910.GA22985@gmail.com> <50C94A9C.2050900@gmail.com> <50C94ECD.6020504@gmail.com> <50C95A21.1010101@gmail.com> <20121213073056.GA13156@gmail.com> In-Reply-To: <20121213073056.GA13156@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/13/12 12:30 AM, Ingo Molnar wrote: > > * David Ahern wrote: > >>> But doing it this way was wrong. Switch that "exclude_guest" >>> attribute around, and admit that "H" was bogus, and that the >>> right thing to do was to add a "V" flag that sets the >>> "force_guest" flag instead. >> >> I understand this is annoying. [...] > > It's not annoying, it's outright broken - it's a regression that > we'll fix. One of the problems is that existing binaries set the exclude_guest flag (https://lkml.org/lkml/2012/7/9/292). So, requesting users to update their binaries if they want to use precise sampling is not acceptable. A 100% catastrophic failure of all running VMs is acceptable? All VMs will crash and there is no direct causal relationship. David