Re: [PATCH] ftrace: Provide trace clock monotonic raw

From: Mathieu Desnoyers
Date: Mon May 04 2015 - 11:10:37 EST


----- Original Message -----
> Expose the NMI safe accessor to the monotonic raw clock to the
> tracer. The mono clock was added with commit
> 1b3e5c0936046e7e023149ddc8946d21c2ea20eb. Although the monotonic raw
> clock cannot be used to compare time between different machines, it is
> not perterbed by ntp.

perterbed -> perturbed

>
> Signed-off-by: Drew Richardson <drew.richardson@xxxxxxx>
>

What is the use-case that justify exposing the "raw fast"
clock that cannot be handled by the "monotonic fast" clock ?

Thanks,

Mathieu

> ---
> kernel/trace/trace.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index 05330494a0df..458031c31a37 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -876,6 +876,7 @@ static struct {
> { trace_clock_jiffies, "uptime", 0 },
> { trace_clock, "perf", 1 },
> { ktime_get_mono_fast_ns, "mono", 1 },
> + { ktime_get_raw_fast_ns, "mono_raw", 1 },
> ARCH_TRACE_CLOCKS
> };
>
> --
> 2.1.4
>
>

--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
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