Re: [PATCH bpf-next] bpf: add 'BPF_RB_MAY_WAKEUP' flag

[Pedro Tammela]

Em qua., 31 de mar. de 2021 às 03:54, Andrii Nakryiko
<andrii.nakryiko@xxxxxxxxx> escreveu:
>
> On Sun, Mar 28, 2021 at 9:11 AM Pedro Tammela <pctammela@xxxxxxxxx> wrote:
> >
> > The current way to provide a no-op flag to 'bpf_ringbuf_submit()',
> > 'bpf_ringbuf_discard()' and 'bpf_ringbuf_output()' is to provide a '0'
> > value.
> >
> > A '0' value might notify the consumer if it already caught up in processing,
> > so let's provide a more descriptive notation for this value.
> >
> > Signed-off-by: Pedro Tammela <pctammela@xxxxxxxxxxxx>
> > ---
>
> flags == 0 means "no extra modifiers of behavior". That's default
> adaptive notification. If you want to adjust default behavior, only
> then you specify non-zero flags. I don't think anyone will bother
> typing BPF_RB_MAY_WAKEUP for this, nor I think it's really needed. The
> documentation update is nice (if no flags are specified notification
> will be sent if needed), but the new "pseudo-flag" seems like an
> overkill to me.

My intention here is to make '0' more descriptive.
But if you think just the documentation update is enough, then I will
remove the flag.

>
> >  include/uapi/linux/bpf.h                               | 8 ++++++++
> >  tools/include/uapi/linux/bpf.h                         | 8 ++++++++
> >  tools/testing/selftests/bpf/progs/ima.c                | 2 +-
> >  tools/testing/selftests/bpf/progs/ringbuf_bench.c      | 2 +-
> >  tools/testing/selftests/bpf/progs/test_ringbuf.c       | 2 +-
> >  tools/testing/selftests/bpf/progs/test_ringbuf_multi.c | 2 +-
> >  6 files changed, 20 insertions(+), 4 deletions(-)
> >
>
> [...]