Re: [KVM PATCH v4 2/2] kvm: add support for irqfd via eventfd-notification interface

Avi Kivity
2009-05-08T08:20:10Z

Davide Libenzi wrote:
> On Thu, 7 May 2009, Avi Kivity wrote:
>
>
>> What's your take on adding irq context safe callbacks to irqfd?
>>
>> To give some background here, we would like to use eventfd as a generic
>> connector between components, so the components do not know about each other.
>> So far eventfd successfully abstracts among components in the same process, in
>> different processes, and in the kernel.
>>
>> eventfd_signal() can be safely called from irq context, and will wake up a
>> waiting task. But in some cases, if the consumer is in the kernel, it may be
>> able to consume the event from irq context, saving a context switch.
>>
>> So, will you consider patches adding this capability to eventfd?
>>
>
> Since I received this one after your ACK on the capability of eventfd of
> triggering callbacks, I assume we're clear on this point, aren't we?
>

We are.

--
Do not meddle in the internals of kernels, for they are subtle and quick to panic.