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From: Don Zickus <dzickus@redhat.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>, LKML <linux-kernel@vger.kernel.org>,
	uobergfe@redhat.com, Don Zickus <dzickus@redhat.com>
Subject: [PATCH 2/9] watchdog: introduce the proc_watchdog_update() function
Date: Tue,  4 Nov 2014 11:20:17 -0500	[thread overview]
Message-ID: <1415118024-194247-3-git-send-email-dzickus@redhat.com> (raw)
In-Reply-To: <1415118024-194247-1-git-send-email-dzickus@redhat.com>

From: Ulrich Obergfell <uobergfe@redhat.com>

This series introduces a separate handler for each watchdog parameter
in /proc/sys/kernel. The separate handlers need a common function that
they can call to update the run state of the lockup detectors, or to
have the lockup detectors use a new sample period.

Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
---
 kernel/watchdog.c |   23 +++++++++++++++++++++++
 1 files changed, 23 insertions(+), 0 deletions(-)

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 91e7bff..dcf28b2 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -679,6 +679,29 @@ static void watchdog_disable_all_cpus(void)
 }
 
 /*
+ * Update the run state of the lockup detectors.
+ */
+static int proc_watchdog_update(void)
+{
+	int err = 0;
+
+	/*
+	 * Watchdog threads won't be started if they are already active.
+	 * The 'watchdog_running' variable in watchdog_*_all_cpus() takes
+	 * care of this. If those threads are already active, the sample
+	 * period will be updated and the lockup detectors will be enabled
+	 * or disabled 'on the fly'.
+	 */
+	if (watchdog_enabled && watchdog_thresh)
+		err = watchdog_enable_all_cpus(true);
+	else
+		watchdog_disable_all_cpus();
+
+	return err;
+
+}
+
+/*
  * proc handler for /proc/sys/kernel/nmi_watchdog,watchdog_thresh
  */
 
-- 
1.7.1


  parent reply	other threads:[~2014-11-04 16:21 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-04 16:20 [PATCH 0/9] watchdog: internally split softlockup and hardlockup Don Zickus
2014-11-04 16:20 ` [PATCH 1/9] watchdog: new definitions and variables, initialization Don Zickus
2014-11-04 16:20 ` Don Zickus [this message]
2014-11-04 16:20 ` [PATCH 3/9] watchdog: move definition of 'watchdog_proc_mutex' outside of proc_dowatchdog() Don Zickus
2014-11-04 16:20 ` [PATCH 4/9] watchdog: introduce the proc_watchdog_common() function Don Zickus
2014-11-04 16:20 ` [PATCH 5/9] watchdog: introduce separate handlers for parameters in /proc/sys/kernel Don Zickus
2014-11-04 16:20 ` [PATCH 6/9] watchdog: implement error handling for failure to set up hardware perf events Don Zickus
2014-11-04 16:20 ` [PATCH 7/9] watchdog: enable the new user interface of the watchdog mechanism Don Zickus
2014-11-04 16:20 ` [PATCH 8/9] watchdog: clean up some function names and arguments Don Zickus
2014-11-04 16:20 ` [PATCH 9/9] watchdog: introduce the hardlockup_detector_disable() function Don Zickus
2014-12-17 21:25 ` [PATCH 0/9] watchdog: internally split softlockup and hardlockup Don Zickus
2015-01-21 14:15 ` Don Zickus
2015-01-21 22:23   ` Andrew Morton
2015-02-05 20:40 Don Zickus
2015-02-05 20:40 ` [PATCH 2/9] watchdog: introduce the proc_watchdog_update() function Don Zickus

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