Subject: Re: 4.19: udpgso_bench_tx: setsockopt zerocopy: Unknown error 524

From: Greg KH <[email-masked]>
Date: Tue, 18 Jun 2019 18:10:36 +0200

On Tue, Jun 18, 2019 at 08:31:16AM -0400, Willem de Bruijn wrote:
> On Tue, Jun 18, 2019 at 7:27 AM Naresh Kamboju
> <[email-masked]> wrote:
> >
> > selftests: net: udpgso_bench.sh failed on 4.19, 4.14, 4.9 and 4.4 branches.
> > PASS on stable branch 5.1, mainline and next.
> > This failure is started happening on 4.19 and older kernel branches after
> > kselftest upgrade to version 5.1
> 
> Does version 5.1 here mean running tests from Linux 5.1, against older kernels?
> 
> > Is there any possibilities to backport ?
> >
> > Error:
> > udpgso_bench_tx: setsockopt zerocopy: Unknown error 524
> 
> MSG_ZEROCOPY for UDP was added in commit b5947e5d1e71 ("udp:
> msg_zerocopy") in Linux 5.0.
> 
> The selftest was expanded with this feature in commit db63e489c7aa
> ("selftests: extend zerocopy tests to udp"), also in Linux 5.0.
> 
> Those tests are not expected to pass on older kernels.

Any way to degrade gracefully if the feature is not present at all in
the kernel under test?  People run the latest version of kselftests on
older kernels all the time.

thanks,

greg k-h