From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933305Ab3CLSuL (ORCPT ); Tue, 12 Mar 2013 14:50:11 -0400 Received: from nat-pool-12-rdu.redhat.com ([66.187.233.206]:31155 "EHLO intel-canoepass-08.lab.bos.redhat.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S932612Ab3CLSuJ (ORCPT ); Tue, 12 Mar 2013 14:50:09 -0400 X-Greylist: delayed 346 seconds by postgrey-1.27 at vger.kernel.org; Tue, 12 Mar 2013 14:50:09 EDT From: Don Zickus To: akpm@linux-foundation.org Cc: LKML , mingo@kernel.org, chuansheng.liu@intel.com, paulmck@linux.vnet.ibm.com, anish kumar , Don Zickus Subject: [PATCH] Add comments to explain watchdog_disabled variable Date: Tue, 12 Mar 2013 14:44:08 -0400 Message-Id: <1363113848-18344-1-git-send-email-dzickus@redhat.com> X-Mailer: git-send-email 1.7.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: anish kumar This watchdog_disabled flag is a bit cryptic. However it's usefulness is multifold. Uses are: 1. Check if smpboot_register_percpu_thread function passed. 2. Makes sure that user enables and disables the watchdog in sequence i.e. enable watchdog->disable watchdog->enable watchdog Unlike enable watchdog->enable watchdog which is wrong. Signed-off-by: anish kumar [small text cleanups] Signed-off-by: Don Zickus --- kernel/watchdog.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 75a2ab3..238477b 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -518,6 +518,11 @@ int proc_dowatchdog(struct ctl_table *table, int write, return ret; set_sample_period(); + /* + * Watchdog threads shouldn't be enabled if they are + * disabled. The 'watchdog_disabled' variable check in + * watchdog_*_all_cpus() function takes care of this. + */ if (watchdog_enabled && watchdog_thresh) watchdog_enable_all_cpus(); else -- 1.7.1