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authorStephen Rothwell <sfr@canb.auug.org.au>2008-08-22 10:42:23 +1000
committerStephen Rothwell <sfr@canb.auug.org.au>2008-08-22 10:42:23 +1000
commitbe21d065e6d1443c0720d76502513c5efe418403 (patch)
tree623a67a7f7beb744535032ceba6ac2d11dd46c53 /kernel/sched_clock.c
parent44fbdd467bea6c7fadab795176a15da167b86859 (diff)
parentcdca408f6f55290eec706abad51826e113f2a091 (diff)
Merge commit 'ftrace/auto-ftrace-next'
Conflicts: kernel/module.c
Diffstat (limited to 'kernel/sched_clock.c')
-rw-r--r--kernel/sched_clock.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/kernel/sched_clock.c b/kernel/sched_clock.c
index 204991a0bfa7..24b0092fac11 100644
--- a/kernel/sched_clock.c
+++ b/kernel/sched_clock.c
@@ -31,6 +31,7 @@
#include <linux/spinlock.h>
#include <linux/ktime.h>
#include <linux/module.h>
+#include <linux/hardirq.h>
/*
* Scheduler clock - returns current time in nanosec units.
@@ -151,6 +152,13 @@ u64 sched_clock_cpu(int cpu)
struct sched_clock_data *scd = cpu_sdc(cpu);
u64 now, clock, this_clock, remote_clock;
+ /*
+ * 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;