diff options
| author | Marcin Slusarz <marcin.slusarz@gmail.com> | 2011-01-28 11:00:31 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-02-17 15:15:04 -0800 |
| commit | 9e93a2ffc5ae0c527331a3600f93894547df62ec (patch) | |
| tree | 76b007b3452535d4cb5b46501783509ceb6ff5c5 /kernel | |
| parent | 4cb138966a04517845f625ed142e103a9313eb9b (diff) | |
watchdog: Fix broken nowatchdog logic
commit 4135038a582c20ffdadfcf6564852e0b72a20968 upstream.
Passing nowatchdog to kernel disables 2 things: creation of
watchdog threads AND initialization of percpu watchdog_hrtimer.
As hrtimers are initialized only at boot it's not possible to
enable watchdog later - for me all watchdog threads started to
eat 100% of CPU time, but they could just crash.
Additionally, even if these threads would start properly,
watchdog_disable_all_cpus was guarded by no_watchdog check, so
you couldn't disable watchdog.
To fix this, remove no_watchdog variable and use already
existing watchdog_enabled variable.
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
[ removed another no_watchdog instance ]
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1296230433-6261-1-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/watchdog.c | 18 |
1 files changed, 5 insertions, 13 deletions
diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 2886c0388f93..32a9ce5efcc0 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -27,7 +27,7 @@ #include <asm/irq_regs.h> #include <linux/perf_event.h> -int watchdog_enabled; +int watchdog_enabled = 1; int __read_mostly softlockup_thresh = 60; static DEFINE_PER_CPU(unsigned long, watchdog_touch_ts); @@ -43,9 +43,6 @@ static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts_saved); static DEFINE_PER_CPU(struct perf_event *, watchdog_ev); #endif -static int no_watchdog; - - /* boot commands */ /* * Should we panic when a soft-lockup or hard-lockup occurs: @@ -75,7 +72,7 @@ __setup("softlockup_panic=", softlockup_panic_setup); static int __init nowatchdog_setup(char *str) { - no_watchdog = 1; + watchdog_enabled = 0; return 1; } __setup("nowatchdog", nowatchdog_setup); @@ -83,7 +80,7 @@ __setup("nowatchdog", nowatchdog_setup); /* deprecated */ static int __init nosoftlockup_setup(char *str) { - no_watchdog = 1; + watchdog_enabled = 0; return 1; } __setup("nosoftlockup", nosoftlockup_setup); @@ -475,9 +472,6 @@ static void watchdog_disable_all_cpus(void) { int cpu; - if (no_watchdog) - return; - for_each_online_cpu(cpu) watchdog_disable(cpu); @@ -531,7 +525,8 @@ cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) break; case CPU_ONLINE: case CPU_ONLINE_FROZEN: - err = watchdog_enable(hotcpu); + if (watchdog_enabled) + err = watchdog_enable(hotcpu); break; #ifdef CONFIG_HOTPLUG_CPU case CPU_UP_CANCELED: @@ -556,9 +551,6 @@ static int __init spawn_watchdog_task(void) void *cpu = (void *)(long)smp_processor_id(); int err; - if (no_watchdog) - return 0; - err = cpu_callback(&cpu_nfb, CPU_UP_PREPARE, cpu); WARN_ON(notifier_to_errno(err)); |