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

From: Davide Libenzi
Date: Thu May 07 2009 - 10:51:31 EST


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?

Maybe I got lost in the thread, but inside the kernel we have
callback-based wakeup since long time. This is what epoll uses, when
hooking into the file* f_op->poll() subsystem.
Did you mean something else?


- Davide


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/