Re: [PATCH net v2] vsock/test: Fix occasional failure in SIOCOUTQ tests

[Paolo Abeni <pabeni@redhat.com>]

On 5/7/25 5:14 PM, Konstantin Shkolnyy wrote:
> These tests:
>     "SOCK_STREAM ioctl(SIOCOUTQ) 0 unsent bytes"
>     "SOCK_SEQPACKET ioctl(SIOCOUTQ) 0 unsent bytes"
> output: "Unexpected 'SIOCOUTQ' value, expected 0, got 64 (CLIENT)".
> 
> They test that the SIOCOUTQ ioctl reports 0 unsent bytes after the data
> have been received by the other side. However, sometimes there is a delay
> in updating this "unsent bytes" counter, and the test fails even though
> the counter properly goes to 0 several milliseconds later.
> 
> The delay occurs in the kernel because the used buffer notification
> callback virtio_vsock_tx_done(), called upon receipt of the data by the
> other side, doesn't update the counter itself. It delegates that to
> a kernel thread (via vsock->tx_work). Sometimes that thread is delayed
> more than the test expects.
> 
> Change the test to poll SIOCOUTQ until it returns 0 or a timeout occurs.
> 
> Signed-off-by: Konstantin Shkolnyy <kshk@linux.ibm.com>

Could you please provide a suitable fixes tag?

No need to repost, just reply here.

Thanks!

Paolo