Re: [PATCH 1/2] x86/intel_rdt/mbm: Fix MBM overflow handler during hot cpu

From: Thomas Gleixner
Date: Wed Aug 16 2017 - 05:20:00 EST


On Tue, 15 Aug 2017, Vikas Shivappa wrote:
> When a CPU is dying, we cancel the worker and schedule a new worker on a
> different CPU on the same domain. But if the timer is already about to
> expire (say 0.99s) then we essentially double the interval.
>
> We modify the hot cpu handling to cancel the delayed work on the dying
> cpu and run the worker immediately on a different cpu in same domain. We
> donot flush the worker because the MBM overflow worker reschedules the
> worker on same CPU and scans the domain->cpu_mask to get the domain
> pointer.

You could alternatively use flush and make the worker code schedule the
work on a still online CPU in the domain instead of blindly rescheduling it
on the same CPU.

Thanks,

tglx