Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753471AbcKUR7u (ORCPT ); Mon, 21 Nov 2016 12:59:50 -0500 Received: from mx1.redhat.com ([209.132.183.28]:36364 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752264AbcKUR7t (ORCPT ); Mon, 21 Nov 2016 12:59:49 -0500 Message-ID: <58333613.50408@redhat.com> Date: Mon, 21 Nov 2016 12:59:47 -0500 From: Prarit Bhargava User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Don Zickus CC: linux-kernel@vger.kernel.org, Borislav Petkov , Tejun Heo , Hidehiro Kawai , Thomas Gleixner , Andi Kleen , Joshua Hunt , Ingo Molnar Subject: Re: [PATCH] kernel/watchdog.c: Only output hw-PMU message once References: <1479746119-25239-1-git-send-email-prarit@redhat.com> <20161121174858.GB35881@redhat.com> In-Reply-To: <20161121174858.GB35881@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Mon, 21 Nov 2016 17:59:48 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1985 Lines: 61 On 11/21/2016 12:48 PM, Don Zickus wrote: > On Mon, Nov 21, 2016 at 11:35:19AM -0500, Prarit Bhargava wrote: >> When CONFIG_BOOTPARAM_HOTPLUG_CPU0 is enabled, the socket containing the >> boot cpu can be replaced. During the hot add event, the message >> >> NMI watchdog: enabled on all CPUs, permanently consumes one hw-PMU counter. >> >> is output implying that the NMI was disabled at some point. This is not the >> case and the message has caused confusion for users of systems that support >> socket removal. >> >> This patch modifies the message so that it only outputs a single time >> during runtime. > > Hmm, it occurred to me, with pr_info_once, what happens if you disable and > re-enable, is this still printed? > > echo 0 > /proc/sys/kernel/watchdog > echo 1 > /proc/sys/kernel/watchdog With my patch, the message is not printed using the above steps. I'll go back and see if I can figure something out. P. > > Cheers, > Don > >> >> Signed-off-by: Prarit Bhargava >> Cc: Borislav Petkov >> Cc: Tejun Heo >> Cc: Don Zickus >> Cc: Hidehiro Kawai >> Cc: Thomas Gleixner >> Cc: Andi Kleen >> Cc: Joshua Hunt >> Cc: Ingo Molnar >> --- >> kernel/watchdog.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/kernel/watchdog.c b/kernel/watchdog.c >> index 9acb29f280ec..560414692c01 100644 >> --- a/kernel/watchdog.c >> +++ b/kernel/watchdog.c >> @@ -615,7 +615,7 @@ static int watchdog_nmi_enable(unsigned int cpu) >> if (!IS_ERR(event)) { >> /* only print for cpu0 or different than cpu0 */ >> if (cpu == 0 || cpu0_err) >> - pr_info("enabled on all CPUs, permanently consumes one hw-PMU counter.\n"); >> + pr_info_once("enabled on all CPUs, permanently consumes one hw-PMU counter.\n"); >> goto out_save; >> } >> >> -- >> 1.7.9.3 >>