Re: [Qemu-devel] [RFC] Next gen kvm api

[Avi Kivity]

On 02/07/2012 06:19 PM, Anthony Liguori wrote:
>> Ah. But then ioeventfd has that as well, unless the other end is in
>> the kernel too.
>
>
> Yes, that was my point exactly :-)
>
> ioeventfd/mmio-over-socketpair to adifferent thread is not faster than
> a synchronous KVM_RUN + writing to an eventfd in userspace modulo a
> couple of cheap syscalls.
>
> The exception is when the other end is in the kernel and there is
> magic optimizations (like there is today with ioeventfd).

vhost seems to schedule a workqueue item unconditionally.

irqfd does have magic optimizations to avoid an extra schedule.

-- 
error compiling committee.c: too many arguments to function

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