From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757219Ab3GEJym (ORCPT ); Fri, 5 Jul 2013 05:54:42 -0400 Received: from terminus.zytor.com ([198.137.202.10]:59940 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757048Ab3GEJyl (ORCPT ); Fri, 5 Jul 2013 05:54:41 -0400 Date: Fri, 5 Jul 2013 02:54:29 -0700 From: tip-bot for Stephane Eranian Message-ID: Cc: linux-kernel@vger.kernel.org, eranian@google.com, hpa@zytor.com, mingo@kernel.org, tglx@linutronix.de Reply-To: mingo@kernel.org, hpa@zytor.com, eranian@google.com, linux-kernel@vger.kernel.org, tglx@linutronix.de In-Reply-To: <20130704223010.GA30625@quad> References: <20130704223010.GA30625@quad> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] perf: Fix interrupt handler timing harness Git-Commit-ID: e5302920da9ef23f9d19d4e9ac85704cc25bee7a X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.7 (terminus.zytor.com [127.0.0.1]); Fri, 05 Jul 2013 02:54:36 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: e5302920da9ef23f9d19d4e9ac85704cc25bee7a Gitweb: http://git.kernel.org/tip/e5302920da9ef23f9d19d4e9ac85704cc25bee7a Author: Stephane Eranian AuthorDate: Fri, 5 Jul 2013 00:30:11 +0200 Committer: Ingo Molnar CommitDate: Fri, 5 Jul 2013 08:54:43 +0200 perf: Fix interrupt handler timing harness This patch fixes a serious bug in: 14c63f17b1fd perf: Drop sample rate when sampling is too slow There was an misunderstanding on the API of the do_div() macro. It returns the remainder of the division and this was not what the function expected leading to disabling the interrupt latency watchdog. This patch also remove a duplicate assignment in perf_sample_event_took(). Signed-off-by: Stephane Eranian Cc: peterz@infradead.org Cc: dave.hansen@linux.intel.com Cc: ak@linux.intel.com Cc: jolsa@redhat.com Link: http://lkml.kernel.org/r/20130704223010.GA30625@quad Signed-off-by: Ingo Molnar --- kernel/events/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 1db3af9..1833bc5 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -182,7 +182,7 @@ void update_perf_cpu_limits(void) u64 tmp = perf_sample_period_ns; tmp *= sysctl_perf_cpu_time_max_percent; - tmp = do_div(tmp, 100); + do_div(tmp, 100); atomic_set(&perf_sample_allowed_ns, tmp); } @@ -232,7 +232,7 @@ DEFINE_PER_CPU(u64, running_sample_length); void perf_sample_event_took(u64 sample_len_ns) { u64 avg_local_sample_len; - u64 local_samples_len = __get_cpu_var(running_sample_length); + u64 local_samples_len; if (atomic_read(&perf_sample_allowed_ns) == 0) return;