On Thu, Jul 17, 2014 at 7:08 PM, Steven Rostedt <[email protected]> wrote:
>> Do we really need to convert to nanoseconds? Couldn't we just return
>> jiffies:
>
> Sure, and we can make it a "counter". That is, the counters don't hide
> 1000 counts on output.
Can you explain that a bit more ... how do we mark it as a "counter"?
>> u64 notrace trace_clock_jiffies(void)
>> {
>> return jiffies_64 - INITIAL_JIFFIES;
>> }
Hmm it seems that we make it hard for applications to see what HZ
value the kernel is actually using. All user-facing interfaces should
convert to USER_HZ (100). So we should say:
u64 notrace trace_clock_jiffies(void)
{
return jiffies_64_to_clock_t(jiffies_64 - INITIAL_JIFFIES);
}
Do we need to change anything in Documentation/trace/ftrace.txt?
Currently it says:
uptime: This uses the jiffies counter and the time stamp
is relative to the time since boot up.
-Tony
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