[TEST] dpdk/app/test/test_mbuf.c test_refcnt_mbuf instability + fix proposal

[Julien Hascoet]

Here is a patch, I let you amend it if needed as I'm a beginner in the dpdk project

Thanks
________________________________
De : David Marchand <david.marchand at redhat.com>
Envoyé : lundi 7 août 2023 09:26
À : Julien Hascoet <jhascoet at kalrayinc.com>; Olivier Matz <olivier.matz at 6wind.com>
Cc : dev at dpdk.org <dev at dpdk.org>
Objet : Re: [TEST] dpdk/app/test/test_mbuf.c test_refcnt_mbuf instability + fix proposal

Hello Julien,

On Mon, Aug 7, 2023 at 8:19 AM Julien Hascoet <jhascoet at kalrayinc.com> wrote:
> from my understanding after debugging, in test_refcnt_iter the return value of rte_ring_enqueue is not checked; leading to lack of expected mbufs at the end checks.
>
> Here is some fix proposal that seems to work after running endurance tests for several days:
>
> diff --git a/app/test/test_mbuf.c b/app/test/test_mbuf.c
> index b4f436b5e2..8a5d26e4f6 100644
> --- a/app/test/test_mbuf.c
> +++ b/app/test/test_mbuf.c
> @@ -1033,12 +1033,17 @@ test_refcnt_iter(unsigned int lcore, unsigned int iter,
>                 tref += ref;
>                 if ((ref & 1) != 0) {
>                         rte_pktmbuf_refcnt_update(m, ref);
> -                       while (ref-- != 0)
> -                               rte_ring_enqueue(refcnt_mbuf_ring, m);
> +                       while (ref-- != 0) {
> +                               /* retry in case of failure */
> +                               while (rte_ring_enqueue(refcnt_mbuf_ring, m) != 0)
> +                                       ;
> +                       }
>                 } else {
>                         while (ref-- != 0) {
>                                 rte_pktmbuf_refcnt_update(m, 1);
> -                               rte_ring_enqueue(refcnt_mbuf_ring, m);
> +                               /* retry in case of failure */
> +                               while (rte_ring_enqueue(refcnt_mbuf_ring, m) != 0)
> +                                       ;
>                         }
>                 }
>                 rte_pktmbuf_free(m);
>
> Can you confirm ?

This analysis looks correct (though failing to enqueue in this unit
test seems strange to me).
Could you send a fix with a Fixes: line in the commitlog, and copying
the maintainer?

Thanks.


--
David Marchand







-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mails.dpdk.org/archives/dev/attachments/20230807/ad4515c9/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-app-fix-silent-enqueue-fail-in-test_mbuf-test_refcnt.patch
Type: text/x-patch
Size: 1219 bytes
Desc: 0001-app-fix-silent-enqueue-fail-in-test_mbuf-test_refcnt.patch
URL: <http://mails.dpdk.org/archives/dev/attachments/20230807/ad4515c9/attachment.bin>