Re: [PATCH RFC 1/1] genirq: Make threaded handler use irq affinity for managed interrupt

From: John Garry
Date: Fri Dec 13 2019 - 12:50:52 EST


On 13/12/2019 17:12, Ming Lei wrote:
pu list 80-83, effective list 81
irq 97, cpu list 84-87, effective list 86
irq 98, cpu list 88-91, effective list 89
irq 99, cpu list 92-95, effective list 93
john@ubuntu:~$

I'm now thinking that we should just attempt this intelligent CPU affinity
assignment for managed interrupts.
Right, the rule is simple: distribute effective list among CPUs evenly,
meantime select the effective CPU from the irq's affinity mask.


Even if we fix that, there is still a potential to have a CPU handling multiple nvme completion queues due to many factors, like cpu count, probe ordering, other PCI endpoints in the system, etc, so this lockup needs to be remedied.

Thanks,
John