Re: [PATCH net] virtio-net: disable NAPI only when enabled during XDP set

From: David Miller
Date: Wed Feb 28 2018 - 12:22:44 EST


From: Jason Wang <jasowang@xxxxxxxxxx>
Date: Wed, 28 Feb 2018 18:20:04 +0800

> We try to disable NAPI to prevent a single XDP TX queue being used by
> multiple cpus. But we don't check if device is up (NAPI is enabled),
> this could result stall because of infinite wait in
> napi_disable(). Fixing this by checking device state through
> netif_running() before.
>
> Fixes: 4941d472bf95b ("virtio-net: do not reset during XDP set")
> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>

Yes, mis-paired NAPI enable/disable are really a pain.

Probably, we can do something in the interfaces or mechanisms to make
this less error prone and less fragile.

Anyways, applied and queued up for -stable, thanks!