* 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>
*/
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;
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();