The sample code talks about single-queue devices and uses locks.
Update it to something resembling more modern code.
Make sure we mention use of READ_ONCE() / WRITE_ONCE().
Change the comment which talked about consumer on the xmit side.
AFAIU xmit is the producer and completions are a consumer.
Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>