diff options
Diffstat (limited to 'kernel/sched_clock.c')
| -rw-r--r-- | kernel/sched_clock.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/kernel/sched_clock.c b/kernel/sched_clock.c index 390f33234bd..e1d16c9a768 100644 --- a/kernel/sched_clock.c +++ b/kernel/sched_clock.c @@ -25,6 +25,7 @@ * consistent between cpus (never more than 2 jiffies difference). */ #include <linux/spinlock.h> +#include <linux/hardirq.h> #include <linux/module.h> #include <linux/percpu.h> #include <linux/ktime.h> @@ -37,7 +38,8 @@ */ unsigned long long __attribute__((weak)) sched_clock(void) { - return (unsigned long long)jiffies * (NSEC_PER_SEC / HZ); + return (unsigned long long)(jiffies - INITIAL_JIFFIES) + * (NSEC_PER_SEC / HZ); } static __read_mostly int sched_clock_running; @@ -154,6 +156,17 @@ u64 sched_clock_cpu(int cpu) return sched_clock(); scd = cpu_sdc(cpu); + + /* + * Normally this is not called in NMI context - but if it is, + * trying to do any locking here is totally lethal. + */ + if (unlikely(in_nmi())) + return scd->clock; + + if (unlikely(!sched_clock_running)) + return 0ull; + WARN_ON_ONCE(!irqs_disabled()); now = sched_clock(); |