On Thu, 7 May 2009, Avi Kivity wrote: > Davide Libenzi 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? > > > > Do you mean wait_queue_t::func? Yes, it is since long time ago that a wakeup in Linux can lead either to a real wakeup (in scheduler terms), or to a simple function call. Isn't that enough? - Davide -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
