Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751253AbdGPDDP (ORCPT ); Sat, 15 Jul 2017 23:03:15 -0400 Received: from mail-it0-f65.google.com ([209.85.214.65]:33528 "EHLO mail-it0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751213AbdGPDDN (ORCPT ); Sat, 15 Jul 2017 23:03:13 -0400 From: Vince Weaver X-Google-Original-From: Vince Weaver Date: Sat, 15 Jul 2017 23:03:06 -0400 (EDT) X-X-Sender: vince@macbook-air To: Ingo Molnar cc: linux-kernel@vger.kernel.org, Alexander Shishkin , Peter Zijlstra , Stephane Eranian , Jiri Olsa , Arnaldo Carvalho de Melo , Thomas Gleixner Subject: Re: perf: bisected sampling bug in Linux 4.11-rc1 In-Reply-To: Message-ID: References: <20170715110049.36jvxnidy2flh6ll@gmail.com> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 765 Lines: 18 On Sat, 15 Jul 2017, Vince Weaver wrote: > Although there is a separate issue also introduced in 4.11-rc1 that still > fails a different testcase. I'm in the middle of bisecting that one and > probably won't have the result of the bisect until Monday. I went and bisected the other issue anyway. It wasn't in 4.11-rc1, but in 4.12-rc4. Yes, I have a test that triggered the c1582c231ea041 perf/core: Drop kernel samples even though :u is specified issue. The test was actually losing 7% of its samples, so not just a single sample here or there. The test had two events sampling, one at 100k and one at 200k so I guess every other sample would have two samples immediately back-to-back which must make it more likely to stray into the kernel. Vince