search for: pendg

A subset of my raw data looks like this: -------------- "Grip" "Technique" "Baseline.integrated" "Task" "Stroke..direction." "Engag" "Disen" "PenDG" "PenUG" "PenDS" "PenUS" "Duration" ------------- "Tripod","Barrel","Integrated",7,"S70",230,510,270,510,781,1011,1011 "Tripod","Barrel","Integrate...

...being that moving event idx back might cause some race > condition? This will cause race condition when tx interrupt is enabled. Consider the following cases 1) tx napi was scheduled 2) start_xmit() call virtqueue_enable_cb_delayed() and disable cb, [used event is vq->last_used_idx + 3/4 pendg bufs] 3) tx napi enable the callback by virtqueue_enable_cb() [ used event is vq->last_used_idx ] After step 3, used event was moved back, unnecessary tx interrupt was triggered. > If yes but please describe the race explicitly. > Is there a bug we need to fix on stable? Looks not, curr...

...being that moving event idx back might cause some race > condition? This will cause race condition when tx interrupt is enabled. Consider the following cases 1) tx napi was scheduled 2) start_xmit() call virtqueue_enable_cb_delayed() and disable cb, [used event is vq->last_used_idx + 3/4 pendg bufs] 3) tx napi enable the callback by virtqueue_enable_cb() [ used event is vq->last_used_idx ] After step 3, used event was moved back, unnecessary tx interrupt was triggered. > If yes but please describe the race explicitly. > Is there a bug we need to fix on stable? Looks not, curr...

...>> condition? >> This will cause race condition when tx interrupt is enabled. Consider >> the following cases >> >> 1) tx napi was scheduled >> 2) start_xmit() call virtqueue_enable_cb_delayed() and disable cb, [used >> event is vq->last_used_idx + 3/4 pendg bufs] >> 3) tx napi enable the callback by virtqueue_enable_cb() [ used event is >> vq->last_used_idx ] >> >> After step 3, used event was moved back, unnecessary tx interrupt was >> triggered. > Well unnecessary interrupts are safe. But it that is what we wan...

...>> condition? >> This will cause race condition when tx interrupt is enabled. Consider >> the following cases >> >> 1) tx napi was scheduled >> 2) start_xmit() call virtqueue_enable_cb_delayed() and disable cb, [used >> event is vq->last_used_idx + 3/4 pendg bufs] >> 3) tx napi enable the callback by virtqueue_enable_cb() [ used event is >> vq->last_used_idx ] >> >> After step 3, used event was moved back, unnecessary tx interrupt was >> triggered. > Well unnecessary interrupts are safe. But it that is what we wan...

...cause some race > > condition? > > This will cause race condition when tx interrupt is enabled. Consider > the following cases > > 1) tx napi was scheduled > 2) start_xmit() call virtqueue_enable_cb_delayed() and disable cb, [used > event is vq->last_used_idx + 3/4 pendg bufs] > 3) tx napi enable the callback by virtqueue_enable_cb() [ used event is > vq->last_used_idx ] > > After step 3, used event was moved back, unnecessary tx interrupt was > triggered. Well unnecessary interrupts are safe. With your patch caller of virtqueue_enable_cb will...

This patch checks the new event idx to make sure used event idx never goes back. This is used to synchronize the calls between virtqueue_enable_cb_delayed() and virtqueue_enable_cb(). Cc: Rusty Russell <rusty at rustcorp.com.au> Cc: Michael S. Tsirkin <mst at redhat.com> Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/virtio/virtio_ring.c | 7 +++++-- 1 files

This patch checks the new event idx to make sure used event idx never goes back. This is used to synchronize the calls between virtqueue_enable_cb_delayed() and virtqueue_enable_cb(). Cc: Rusty Russell <rusty at rustcorp.com.au> Cc: Michael S. Tsirkin <mst at redhat.com> Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/virtio/virtio_ring.c | 7 +++++-- 1 files

...;> This will cause race condition when tx interrupt is enabled. Consider > >> the following cases > >> > >> 1) tx napi was scheduled > >> 2) start_xmit() call virtqueue_enable_cb_delayed() and disable cb, [used > >> event is vq->last_used_idx + 3/4 pendg bufs] > >> 3) tx napi enable the callback by virtqueue_enable_cb() [ used event is > >> vq->last_used_idx ] > >> > >> After step 3, used event was moved back, unnecessary tx interrupt was > >> triggered. > > Well unnecessary interrupts are saf...