On Fri, Mar 11, 2011 at 04:49:26PM +1030, Rusty Russell wrote: > But if one side outruns the other, it does a lot of unnecessary work > notifying/interrupting it over and over again before the host/guest gets > a chance to shut notifications/interrupts off. Hence the last_used > publishing patch (Xen does this right, I screwed it up). > > Long weekend here, and I'm otherwise committed. But if noone has > cleaned up that patch by early next week, I'll try to do so and see if > we can make a real difference. > > Cheers, > Rusty. I actually had the last_used publishing patch working. Here it is again: it's the part that publishes the used index from guest and the part that uses it in host to avoid spurious interrupts (this is Tom's case, not Shirley's case) updated to the latest bits, and clarified the code a bit more. Note: there's some tricky logic in the vhost part, I think I got it right but please review. Warning: compiled only, completely untested, I intend to add the bits that use the last available index in guest to reduce exits, test it all together. Would appreciate review and/or testing. Michael S. Tsirkin (2): virtio: put last seen used index into ring itself vhost-net: utilize PUBLISH_USED_IDX feature drivers/vhost/vhost.c | 58 +++++++++++++++++++++++++++++++++++++---- drivers/vhost/vhost.h | 9 ++++++ drivers/virtio/virtio_ring.c | 25 +++++++++++------ include/linux/virtio_ring.h | 11 ++++++++ 4 files changed, 88 insertions(+), 15 deletions(-) -- 1.7.3.2.91.g446ac -- 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
