On Tue, Jun 02, 2009 at 12:14:15PM -0400, Gregory Haskins wrote: > Michael S. Tsirkin wrote: > > On Tue, Jun 02, 2009 at 11:15:28AM -0400, Gregory Haskins wrote: > > > >> (Applies to kvm.git/master:25deed73) > >> > >> Please see the header for 2/2 for a description. This patch series has > >> been fully tested and appears to be working correctly. I have it as an RFC > >> for now because it needs Davide's official submission/SOB for patch 1/2, and > >> it should get some eyeballs/acks on my SRCU usage before going in. > >> > >> I will submit the updated irqfd userspace which eschews the deassign() verb > >> since we can now just use the close(fd) method alone. I will also address > >> the userspace review comments from Avi. > >> > > > > > > We are not killing the deassign though, do we? > > > > Yes, it is not needed any more now that we have proper > release-notification from eventfd. > > > It's good to have that option e.g. for when we pass > > the fd to another process. > > > > Passing the fd to another app should up the underlying file reference > count. If the producer app wants to "deassign" it simply calls > close(fd) (as opposed to today where it calls DEASSIGN+close), but the > reference count will allow the consuming app to leave the eventfd's file > open. Or am I misunderstanding you? > > -Greg > > I think we want to keep supporting the deassign ioctl. This, even though close overlaps with it functionally somewhat. This allows qemu to pass eventfd to another process/device, and then block/unblock interrupts as seen by that process by assigning/deassigning irq to it. This is much easier and lightweight than asking another process to close the fd and passing another fd later. -- MST -- 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
