Messages in this thread | | | Subject | Re: [Xen-devel] [PATCH] xen-evtchn: Bind dyn evtchn:qemu-dm interrupt to next online VCPU | From | Anoob Soman <> | Date | Mon, 5 Jun 2017 17:14:34 +0100 |
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On 05/06/17 16:32, Boris Ostrovsky wrote: > I believe we do need to take affinity into consideration even if the > chance that it is non-default is small.
Agreed.
> I am not opposed to having bind_last_selected_cpu percpu, I just wanted > to understand the reason better. Additional locking would be a downside > with a global so if you feel that percpu is worth it then I won't object.
If affinity == cpu_online_mask, then percpu will give a better spread. atomic set/get can be used, if we want to use a global variable, but I think it will be more random than percpu.
> >> Yes, you are correct. .irq_set_affinity pretty much does the same thing. >> >> The code will now looks like this. >> raw_spin_lock_irqsave(lock, flags); >> percpu read >> select_cpu >> percpu write >> xen_rebind_evtchn_to_cpu(evtchn, selected_cpu) >> raw_spin_unlock_irqsave(lock, flags); > (BTW, I just noticed --- you don't need to initialize desc)
Sorry, I didn't get it. Which desc doesn't need init ?
-Anoob
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