Re: [PATCH net 2/2] selftests: net: packetdrill: add test for negative sk_forward_alloc in tcp_wmem_schedule()

[Eric Dumazet]

Le ven. 16 oct. 2026 à 09:54, Kuniyuki Iwashima <kuniyu@xxxxxxxxxx> a écrit :
>
> On Thu, Oct 15, 2026 at 12:37 AM Octavian Purdila <tavip@xxxxxxxxxx> wrote:
> >
> > Add a packetdrill test that drives sk->sk_forward_alloc negative via
> > tcp_collapse() on the receive queue while sk->sk_wmem_queued exceeds
> > sysctl_tcp_wmem[0], and verifies that a subsequent non-blocking write()
> > under TCP memory pressure fails with EAGAIN rather than returning a
> > negative copy length from tcp_wmem_schedule() and failing with EFAULT.
> >
> > Assisted-by: LLM
> > Signed-off-by: Octavian Purdila <tavip@xxxxxxxxxx>
>
> Reviewed-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
>
> Thanks !

Are you sure this test is passing on arches with 6K pages (as some
arm64 and ppc64 platforms) ?
We might need to add a check to only run it on 4K platforms.