Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751933Ab3JJEEy (ORCPT ); Thu, 10 Oct 2013 00:04:54 -0400 Received: from mail-pd0-f180.google.com ([209.85.192.180]:54173 "EHLO mail-pd0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751125Ab3JJEEx (ORCPT ); Thu, 10 Oct 2013 00:04:53 -0400 Message-ID: <52562760.9010400@linaro.org> Date: Wed, 09 Oct 2013 21:04:48 -0700 From: John Stultz User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.0 MIME-Version: 1.0 To: Dong Zhu , Thomas Gleixner CC: Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: [PATCH RESEND] timer stats: reset entries when disable the timer usage statistics References: <20131010025947.GD2139@zhudong.nay.redhat.com> In-Reply-To: <20131010025947.GD2139@zhudong.nay.redhat.com> X-Enigmail-Version: 1.5.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1373 Lines: 40 On 10/09/2013 07:59 PM, Dong Zhu wrote: > From f41628c61d8a9172677ba33a55b61e37ce28f7a6 Mon Sep 17 00:00:00 2001 > From: Dong Zhu > Date: Thu, 10 Oct 2013 10:38:13 +0800 > > When we stop timer statistics collection (via echo 0 > > /proc/timers_stats), the statistics data is still exported as if it were > correct, which can cause applicaitons to misuse the statistics. > > This patch resets the statistics when we stop collecting them, to avoid > this problem. > > Signed-off-by: Dong Zhu > --- > kernel/time/timer_stats.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/kernel/time/timer_stats.c b/kernel/time/timer_stats.c > index 0b537f2..43f05e7 100644 > --- a/kernel/time/timer_stats.c > +++ b/kernel/time/timer_stats.c > @@ -371,6 +371,7 @@ static ssize_t tstats_write(struct file *file, const char __user *buf, > switch (ctl[0]) { > case '0': > if (timer_stats_active) { > + reset_entries(); > timer_stats_active = 0; > time_stop = ktime_get(); > sync_access(); This looks ok to me. Thomas, do you have any objections here? thanks -john -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/