Re: [RFC PATCH] drivers: char: Add a dynamic clock for the traceclock

From: Steven Rostedt
Date: Wed Dec 11 2013 - 21:11:48 EST


On Wed, 11 Dec 2013 18:06:06 -0800
Sonny Rao <sonnyrao@xxxxxxxxxxxx> wrote:


> > ftrace has several clocks that it uses:
> >
> > o local - basically sched_clock()
> > o global - something like hpet that is monotonic across CPUs but slower
> > o counter - a simple atomic counter (no time associated to it)
> > o uptime - jiffy counter
> > o perf - trace_clock, which is what perf uses
> > o x86_tsc - the raw tsc counter.
> >
> > # cat /sys/kernel/debug/trace_clock
> > [local] global counter uptime perf x86-tsc
> >
>
> Ah ok sorry for the incorrect info there, thanks for clarifying.
> So, If I wanted to make sure everything is synced up between ftrace
> events and perf events I should say perf here instead of local.

Correct, that's why I created that clock.

-- Steve
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