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author | James Morris <jmorris@namei.org> | 2009-05-08 17:56:47 +1000 |
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committer | James Morris <jmorris@namei.org> | 2009-05-08 17:56:47 +1000 |
commit | d254117099d711f215e62427f55dfb8ebd5ad011 (patch) | |
tree | 0848ff8dd74314fec14a86497f8d288c86ba7c65 /kernel/sched_clock.c | |
parent | integrity: remove __setup auditing msgs (diff) | |
parent | NOMMU: Don't check vm_region::vm_start is page aligned in add_nommu_region() (diff) | |
download | linux-dev-d254117099d711f215e62427f55dfb8ebd5ad011.tar.xz linux-dev-d254117099d711f215e62427f55dfb8ebd5ad011.zip |
Merge branch 'master' into next
Diffstat (limited to 'kernel/sched_clock.c')
-rw-r--r-- | kernel/sched_clock.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/kernel/sched_clock.c b/kernel/sched_clock.c index 390f33234bd0..819f17ac796e 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> @@ -154,6 +155,17 @@ 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(); |