On Tue, Jun 23, 2026 at 05:19:01PM +0800, Longjun Tang wrote: > From: Longjun Tang <[email protected]> > > When busy-poll is active, napi_schedule_prep() returns false in > virtqueue_napi_schedule(), so virtqueue_disable_cb() is skipped. > The device may keep firing irqs until reaches virtqueue_napi_complete(). > Under load (received == budget), it will lead to a large number > of spurious interrupts. > > Fix it by disabling the callback at the virtnet_poll() entry. This keeps > the callback off while we poll and re-enable by virtqueue_napi_complete() > when going idle. > > Signed-off-by: Longjun Tang <[email protected]>
Patch is correct Acked-by: Michael S. Tsirkin <[email protected]> Ideally, I like to see performance numbers in such cases, to be included with commit log. > --- > V1 -> V2: Remain agnostic to busy polling > --- > drivers/net/virtio_net.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index f4adcfee7a80..0a11f2b32500 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -3008,6 +3008,11 @@ static int virtnet_poll(struct napi_struct *napi, int > budget) > unsigned int xdp_xmit = 0; > bool napi_complete; > > + /* Keep callbacks suppressed for the duration of this poll, > + * busy-poll need. > + */ > + virtqueue_disable_cb(rq->vq); > + > virtnet_poll_cleantx(rq, budget); > > received = virtnet_receive(rq, budget, &xdp_xmit); > -- > 2.43.0
