On Thu, 2011-07-14 at 17:35 -0700, john stultz wrote:
>
> Peter/Ingo: Can you take a look at the above and let me know if you find
> it too disagreeable?
+static unsigned long long __cycles_2_ns(unsigned long long cyc)
+{
+ unsigned long long ns = 0;
+ struct x86_sched_clock_data *data;
+ int cpu = smp_processor_id();
+
+ rcu_read_lock();
+ data = rcu_dereference(per_cpu(cpu_sched_clock_data, cpu));
+
+ if (unlikely(!data))
+ goto out;
+
+ ns = ((cyc - data->base_cycles) * data->mult) >> CYC2NS_SCALE_FACTOR;
+ ns += data->accumulated_ns;
+out:
+ rcu_read_unlock();
+ return ns;
+}
The way I read that we're still not wrapping properly if freq scaling
'never' happens.
Because then we're wrapping on accumulated_ns + 2^54.
Something like resetting base, and adding ns to accumulated_ns and
returning the latter would make more sense.
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