Re: [PATCH net v2 2/2] vsock/test: add test for small packets under pressure

[Paolo Abeni <pabeni@redhat.com>]

On 7/9/26 11:17 AM, Stefano Garzarella wrote:
> On Wed, Jul 08, 2026 at 06:59:41AM -0400, Michael S. Tsirkin wrote:
>> On Wed, Jul 08, 2026 at 12:29:04PM +0200, Stefano Garzarella wrote:
>>> From: Stefano Garzarella <sgarzare@redhat.com>
>>>
>>> Add a test that sends 2 MB of data using randomly sized small packets
>>> (129-512 bytes) over a SOCK_STREAM connection. Packets above
>>> GOOD_COPY_LEN (128) bypass the in-place coalescing in recv_enqueue(),
>>> forcing each one into its own skb.
>>>
>>> Without receive queue collapsing, the per-skb overhead eventually
>>> exceeds buf_alloc and the connection is reset. The test verifies
>>> that all data arrives and that content integrity is preserved.
>>>
>>> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
>>
>> maybe cut down SO_VM_SOCKETS_BUFFER_SIZE? will make it easier to
>> trigger?
> 
> Currently, with the default value, the trigger is practically immediate 
> for packets between 129 and 512 bytes, but yes, a smaller buffer size 
> certainly makes this effect even more pronounced.
Given that PW is quite in a sorrow status, I think a (net-next)
follow-up is the better option here.

/P