From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754202AbcHSKDV (ORCPT ); Fri, 19 Aug 2016 06:03:21 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:47910 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752244AbcHSKDT (ORCPT ); Fri, 19 Aug 2016 06:03:19 -0400 Date: Fri, 19 Aug 2016 12:01:30 +0200 From: Peter Zijlstra To: Vince Weaver Cc: linux-kernel@vger.kernel.org, Borislav Petkov , Ingo Molnar , Arnaldo Carvalho de Melo , Huang Rui Subject: Re: perf: fuzzer crashes immediately on AMD system Message-ID: <20160819100130.GD10121@twins.programming.kicks-ass.net> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 18, 2016 at 10:46:31AM -0400, Vince Weaver wrote: > On Thu, 18 Aug 2016, Vince Weaver wrote: > > > Tried the perf_fuzzer on my A10 fam15h/model13h system with 4.8-rc2 and it > > falls over more or less immediately. > > > > This maps to variable_test_bit() > > called by ctx = find_get_context(pmu, task, event); > > in kernel/events/core.c:9467 > > > > It happens quickly enough I can probably track down the exact event that > > causes this, if needed. > > I have a one line reproducer: > > perf stat -a -e amd_nb/config=0x37,config1=0x20/ /bin/ls OK, cannot reproduce on my fam15h/model1h. I'll go dig through the various manuals to see if I can spot the fail. Huang could you either prod someone at AMD or do yourself, audit the AMD perf code for all the various new models?