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-rw-r--r--kernel/watchdog.c4
-rw-r--r--kernel/watchdog_hld.c88
2 files changed, 8 insertions, 84 deletions
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index fd8a998eb197..5eb11960e4a2 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -107,6 +107,7 @@ __setup("hardlockup_all_cpu_backtrace=", hardlockup_all_cpu_backtrace_setup);
*/
int __weak watchdog_nmi_enable(unsigned int cpu)
{
+ hardlockup_detector_perf_enable();
return 0;
}
@@ -465,7 +466,8 @@ static void watchdog_enable(unsigned int cpu)
/* Initialize timestamp */
__touch_watchdog();
/* Enable the perf event */
- watchdog_nmi_enable(cpu);
+ if (watchdog_enabled & NMI_WATCHDOG_ENABLED)
+ watchdog_nmi_enable(cpu);
watchdog_set_prio(SCHED_FIFO, MAX_RT_PRIO - 1);
}
diff --git a/kernel/watchdog_hld.c b/kernel/watchdog_hld.c
index 99a3f22e48cc..509bb6b59c41 100644
--- a/kernel/watchdog_hld.c
+++ b/kernel/watchdog_hld.c
@@ -25,7 +25,7 @@ static DEFINE_PER_CPU(struct perf_event *, dead_event);
static struct cpumask dead_events_mask;
static unsigned long hardlockup_allcpu_dumped;
-static bool hardlockup_detector_disabled;
+static unsigned int watchdog_cpus;
void arch_touch_nmi_watchdog(void)
{
@@ -160,84 +160,6 @@ static void watchdog_overflow_callback(struct perf_event *event,
return;
}
-/*
- * People like the simple clean cpu node info on boot.
- * Reduce the watchdog noise by only printing messages
- * that are different from what cpu0 displayed.
- */
-static unsigned long firstcpu_err;
-static atomic_t watchdog_cpus;
-
-int watchdog_nmi_enable(unsigned int cpu)
-{
- struct perf_event_attr *wd_attr;
- struct perf_event *event = per_cpu(watchdog_ev, cpu);
- int firstcpu = 0;
-
- /* nothing to do if the hard lockup detector is disabled */
- if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED))
- goto out;
-
- /* A failure disabled the hardlockup detector permanently */
- if (hardlockup_detector_disabled)
- return -ENODEV;
-
- /* is it already setup and enabled? */
- if (event && event->state > PERF_EVENT_STATE_OFF)
- goto out;
-
- /* it is setup but not enabled */
- if (event != NULL)
- goto out_enable;
-
- if (atomic_inc_return(&watchdog_cpus) == 1)
- firstcpu = 1;
-
- wd_attr = &wd_hw_attr;
- wd_attr->sample_period = hw_nmi_get_sample_period(watchdog_thresh);
-
- /* Try to register using hardware perf events */
- event = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback, NULL);
-
- /* save the first cpu's error for future comparision */
- if (firstcpu && IS_ERR(event))
- firstcpu_err = PTR_ERR(event);
-
- if (!IS_ERR(event)) {
- /* only print for the first cpu initialized */
- if (firstcpu || firstcpu_err)
- pr_info("enabled on all CPUs, permanently consumes one hw-PMU counter.\n");
- goto out_save;
- }
-
- /* skip displaying the same error again */
- if (!firstcpu && (PTR_ERR(event) == firstcpu_err))
- return PTR_ERR(event);
-
- /* vary the KERN level based on the returned errno */
- if (PTR_ERR(event) == -EOPNOTSUPP)
- pr_info("disabled (cpu%i): not supported (no LAPIC?)\n", cpu);
- else if (PTR_ERR(event) == -ENOENT)
- pr_warn("disabled (cpu%i): hardware events not enabled\n",
- cpu);
- else
- pr_err("disabled (cpu%i): unable to create perf event: %ld\n",
- cpu, PTR_ERR(event));
-
- pr_info("Disabling hard lockup detector permanently\n");
- hardlockup_detector_disabled = true;
-
- return PTR_ERR(event);
-
- /* success path */
-out_save:
- per_cpu(watchdog_ev, cpu) = event;
-out_enable:
- perf_event_enable(per_cpu(watchdog_ev, cpu));
-out:
- return 0;
-}
-
static int hardlockup_detector_event_create(void)
{
unsigned int cpu = smp_processor_id();
@@ -267,6 +189,9 @@ void hardlockup_detector_perf_enable(void)
if (hardlockup_detector_event_create())
return;
+ if (!watchdog_cpus++)
+ pr_info("Enabled. Permanently consumes one hw-PMU counter.\n");
+
perf_event_enable(this_cpu_read(watchdog_ev));
}
@@ -282,10 +207,7 @@ void hardlockup_detector_perf_disable(void)
this_cpu_write(watchdog_ev, NULL);
this_cpu_write(dead_event, event);
cpumask_set_cpu(smp_processor_id(), &dead_events_mask);
-
- /* watchdog_nmi_enable() expects this to be zero initially. */
- if (atomic_dec_and_test(&watchdog_cpus))
- firstcpu_err = 0;
+ watchdog_cpus--;
}
}