[Intel-gfx] [PATCH] trace: Default to using trace_global_clock if sched_clock is unstable

[Steven Rostedt]

On Fri, 30 Mar 2018 15:07:53 +0100
Chris Wilson <chris at chris-wilson.co.uk> wrote:


> Sure, I was mainly floating the idea of trying to pick sensible
> defaults. Unstable clocks are quite rare nowadays, the ones we have in
> the lab are a pair of Core2 Duo.

I still have a box too ;-)

I'm not so against having global_clock become default if the TSC is
unstable. But there needs to be a printk warning (not a WARN, but
something like: 

 Warning: TSC unstable, switching tracing_clock default to "global"
 If you want to keep local, then add "trace_clock=local" on the
  kernel command line.

-- Steve