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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2008-08-11 08:59:03 +0200
committerIngo Molnar <mingo@elte.hu>2008-08-11 08:59:03 +0200
commitc1955a3d4762e7a9bf84035eb3c4886a900f0d15 (patch)
treea00dcd1736c612017df7094a91d8a6435b7a49c9 /kernel
parent4a273f209cc95d148f79b4c96d3d03997b44ffda (diff)
sched_clock: delay using sched_clock()
Some arch's can't handle sched_clock() being called too early - delay this until sched_clock_init() has been called. Reported-by: Bill Gatliff <bgat@billgatliff.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Nishanth Aravamudan <nacc@us.ibm.com> CC: Russell King - ARM Linux <linux@arm.linux.org.uk> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/sched_clock.c19
1 files changed, 17 insertions, 2 deletions
diff --git a/kernel/sched_clock.c b/kernel/sched_clock.c
index 074edc989379..204991a0bfa7 100644
--- a/kernel/sched_clock.c
+++ b/kernel/sched_clock.c
@@ -42,6 +42,8 @@ unsigned long long __attribute__((weak)) sched_clock(void)
return (unsigned long long)jiffies * (NSEC_PER_SEC / HZ);
}
+static __read_mostly int sched_clock_running;
+
#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
struct sched_clock_data {
@@ -70,8 +72,6 @@ static inline struct sched_clock_data *cpu_sdc(int cpu)
return &per_cpu(sched_clock_data, cpu);
}
-static __read_mostly int sched_clock_running;
-
void sched_clock_init(void)
{
u64 ktime_now = ktime_to_ns(ktime_get());
@@ -248,6 +248,21 @@ void sched_clock_idle_wakeup_event(u64 delta_ns)
}
EXPORT_SYMBOL_GPL(sched_clock_idle_wakeup_event);
+#else /* CONFIG_HAVE_UNSTABLE_SCHED_CLOCK */
+
+void sched_clock_init(void)
+{
+ sched_clock_running = 1;
+}
+
+u64 sched_clock_cpu(int cpu)
+{
+ if (unlikely(!sched_clock_running))
+ return 0;
+
+ return sched_clock();
+}
+
#endif
unsigned long long cpu_clock(int cpu)

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