Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [PATCH 1/2] cpu/hotplug: Add cpuhp_latency trace event | Date | Mon, 28 Sep 2020 16:58:09 +0200 |
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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
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