watchdog: Disable watchdog when thresh is zero
This restores the previous behavior of softlock_thresh.
Currently, setting watchdog_thresh to zero causes the watchdog
kthreads to consume a lot of CPU.
In addition, the logic of proc_dowatchdog_thresh and
proc_dowatchdog_enabled has been factored into proc_dowatchdog.
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1306127423-3347-3-git-send-email-msb@chromium.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <20110517071018.GE22305@elte.hu>
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index cf0e09f..6030191 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -28,7 +28,7 @@
#include <linux/perf_event.h>
int watchdog_enabled = 1;
-int __read_mostly softlockup_thresh = 60;
+int __read_mostly watchdog_thresh = 60;
static DEFINE_PER_CPU(unsigned long, watchdog_touch_ts);
static DEFINE_PER_CPU(struct task_struct *, softlockup_watchdog);
@@ -105,12 +105,12 @@
static unsigned long get_sample_period(void)
{
/*
- * convert softlockup_thresh from seconds to ns
+ * convert watchdog_thresh from seconds to ns
* the divide by 5 is to give hrtimer 5 chances to
* increment before the hardlockup detector generates
* a warning
*/
- return softlockup_thresh * (NSEC_PER_SEC / 5);
+ return watchdog_thresh * (NSEC_PER_SEC / 5);
}
/* Commands for resetting the watchdog */
@@ -182,7 +182,7 @@
unsigned long now = get_timestamp(smp_processor_id());
/* Warn about unreasonable delays: */
- if (time_after(now, touch_ts + softlockup_thresh))
+ if (time_after(now, touch_ts + watchdog_thresh))
return now - touch_ts;
return 0;
@@ -501,19 +501,19 @@
/* sysctl functions */
#ifdef CONFIG_SYSCTL
/*
- * proc handler for /proc/sys/kernel/nmi_watchdog
+ * proc handler for /proc/sys/kernel/nmi_watchdog,watchdog_thresh
*/
-int proc_dowatchdog_enabled(struct ctl_table *table, int write,
- void __user *buffer, size_t *length, loff_t *ppos)
+int proc_dowatchdog(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
{
int ret;
- ret = proc_dointvec(table, write, buffer, length, ppos);
+ ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
if (ret || !write)
goto out;
- if (watchdog_enabled)
+ if (watchdog_enabled && watchdog_thresh)
watchdog_enable_all_cpus();
else
watchdog_disable_all_cpus();
@@ -521,13 +521,6 @@
out:
return ret;
}
-
-int proc_dowatchdog_thresh(struct ctl_table *table, int write,
- void __user *buffer,
- size_t *lenp, loff_t *ppos)
-{
- return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
-}
#endif /* CONFIG_SYSCTL */