On 07-May-25 10:41, Stefano Garzarella wrote:
On Wed, 7 May 2025 at 17:15, Konstantin Shkolnyy <k...@linux.ibm.com> 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 <k...@linux.ibm.com>
---
Changes in v2:
  - Use timeout_check() to end polling, instead of counting iterations.

Why removing the sleep?

I just imagined that whoever uses SIOCOUTQ might want to repeat it without a delay, so why not do it, it's a test. Is there a reason to insert a sleep?


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