Re: [Xen-devel] xen/arm: VCPU scheduling

[Julien Grall <julien.grall@xxxxxxxxxx>]

On 20/12/2014 20:48, Vijay Kilari wrote:
> Hi,
Hi Vijay,

>     I want to know what is the criteria followed in Xen for scheduling VCPUs.
> Assume below scenario:
>
>   - Run 2 VPCUs on 1 Physical CPU
>   - VCPUs does not trap on WFE or WFE ( either by WFI/WFE trap is
> disabled in HCR OR no WFE/WFI in EL1 is executed).
>
> In such scenario, does Xen assumes that VCPU0 is always running because it has
> NOT trapped on WFI and WFE (not yielded voluntary) and does not
> schedule VCPU1? or is it time shared?
The scheduler allocates time slice to each VCPU. Once the slice is 
ending, another VCPU may be scheduled.
Xen is also trapping WFE/WFI to allow better performance. Why would you 
want to disable WFE/WFI traps?
Regards,

--
Julien Grall

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel