Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030794AbcDMKDc (ORCPT ); Wed, 13 Apr 2016 06:03:32 -0400 Received: from ud10.udmedia.de ([194.117.254.50]:46851 "EHLO mail.ud10.udmedia.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030664AbcDMKDb (ORCPT ); Wed, 13 Apr 2016 06:03:31 -0400 Date: Wed, 13 Apr 2016 12:03:27 +0200 From: Markus Trippelsdorf To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Arnaldo Carvalho de Melo , Alexander Shishkin Subject: Re: "perf: interrupt took too long" messages even with perf_cpu_time_max_percent==0 Message-ID: <20160413100327.GA315@x4> References: <20160402093239.GA305@x4> <20160402110017.GP3448@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160402110017.GP3448@twins.programming.kicks-ass.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 891 Lines: 23 On 2016.04.02 at 13:00 +0200, Peter Zijlstra wrote: > On Sat, Apr 02, 2016 at 11:32:39AM +0200, Markus Trippelsdorf wrote: > > Current git kernel sometimes shows: > > > > perf: interrupt took too long (71 > 52), lowering kernel.perf_event_max_sample_rate to 300 > > perf: interrupt took too long (103 > 88), lowering kernel.perf_event_max_sample_rate to 300 > > perf: interrupt took too long (130 > 128), lowering kernel.perf_event_max_sample_rate to 300 > > perf: interrupt took too long (175 > 162), lowering kernel.perf_event_max_sample_rate to 300 > > perf: interrupt took too long (219 > 218), lowering kernel.perf_event_max_sample_rate to 300 > > ... > > > > when running e.g. "perf top" even when > > /proc/sys/kernel/perf_cpu_time_max_percent is set to 0. > > > Ah, was 0 also meant to disable it? > > Does the below help? Yes, it obviously fixes the issue. -- Markus