Re: [PATCH v1 0/2] *** Support BPF traversal of wakeup sources ***

Samuel Wu
2026-03-23T16:20:46Z

On Sat, Mar 21, 2026 at 10:52 AM Kumar Kartikeya Dwivedi
<memxor@gmail.com> wrote:
>

[ ... ]

> >
> > The initial attempts for BPF traversal of wakeup_sources was with BPF
> > iterators [1]. However, BPF already allows for traversing of a simple list
> > with bpf_for(), and this current patchset has the added benefit of being
> > ~2-3x more performant than BPF iterators.
>
> See, it ended up being faster ;-).

Yup, thanks for the suggestion!

>
> That said, I didn't understand why you dropped the test. We still need
> unit tests that ensure the verifier causes the bpf_ws_lock to be
> released before exit, and an example program (like the one you
> benchmarked with) to demonstrate usage. Both are mandatory. See
> various *_fail.c files in progs/ and RUN_TESTS() macro for running
> negative tests easily. I doubt we will have any wakeup_sources in the
> CI environment, but the example has value nonetheless.
>
> pw-bot: cr
>

Sounds good, in v2 I can add a test for the lock/unlock kfunc. And
thanks for the thorough feedback, let me take a look at the *_fail.c
files and test macros.