Re: [PATCH bpf-next] selftests/bpf: test access to ringbuf position with map pointer

[Menglong Dong <menglong.dong@linux.dev>]

On 2026/3/22 09:51 Emil Tsalapatis <emil@etsalapatis.com> write:
> On Fri Mar 20, 2026 at 4:41 AM EDT, Menglong Dong wrote:
> > Add the testing to access the bpf_ringbuf with the map pointer.
> > "consumer_pos" and "producer_pos" is accessed in this testing. We reserve
> > 128 bytes in the ringbuf to test the producer_pos, which should be
> > "128 + 8", and the "8" is BPF_RINGBUF_HDR_SZ.
> >
> > It will be helpful if we want to evaluate the usage of the ringbuf in bpf
> > prog with the consumer and producer position.
> >
> > Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
> 
> Once Jiri's feedback is addressed feel free to add:
> 
> Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
> 
> One nit below.
[...]
> > +	VERIFY(rb->consumer_pos == 0);
> 
> Nit: Can you repeat here the explanation from the cover letter 
> as to why this is 128 + 8?

OK, I'll add a comment here.

Thanks!
Menglong Dong

> 
> > +	VERIFY(rb->producer_pos == 128 + 8);
> > +
> >  	return 1;
> >  }
> 
> >  
>