* The clock: sched_clock_cpu() is monotonic per cpu, and should be somewhat
* consistent between cpus (never more than 2 jiffies difference).
*/
- #include <linux/sched.h>
- #include <linux/percpu.h>
#include <linux/spinlock.h>
- #include <linux/ktime.h>
- #include <linux/module.h>
+#include <linux/hardirq.h>
+ #include <linux/module.h>
+ #include <linux/percpu.h>
+ #include <linux/ktime.h>
+ #include <linux/sched.h>
/*
* Scheduler clock - returns current time in nanosec units.
u64 sched_clock_cpu(int cpu)
{
- struct sched_clock_data *scd = cpu_sdc(cpu);
u64 now, clock, this_clock, remote_clock;
+ struct sched_clock_data *scd;
+
+ if (sched_clock_stable)
+ 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();