On Wed, Sep 23 2020 at 16:37, Prasad Sodagudi wrote:
> Add ftrace event trace_cpuhp_latency to track cpu
> hotplug latency. It helps to track the hotplug latency
> impact by firmware changes and kernel cpu hotplug callbacks.
Why?
And even if that makes sense, the implementation makes absolutely no
sense at all.
trace_cpuhp_callback_enter();
callback();
trace_cpuhp_callback_exit();
No point in all this start time and conditional sched_clock() muck.
But then again, hotplug is slow by definition and nobody cares.
Thanks,
tglx
