On Tue, May 10, 2022 at 2:17 PM Kumar Kartikeya Dwivedi
<memxor@xxxxxxxxx> wrote:
>
> In an effort to actually test the refcounting logic at runtime, add a
> refcount_t member to prog_test_ref_kfunc and use it in selftests to
> verify and test the whole logic more exhaustively.
>
> To ensure reading the count to verify it remains stable, make
> prog_test_ref_kfunc a per-CPU variable, so that inside a BPF program the
> count can be read reliably based on number of acquisitions made. Then,
> pairing them with releases and reading from the global per-CPU variable
> will allow verifying whether release operations put the refcount.
The patches look good, but the per-cpu part is a puzzle.
The test is not parallel. Everything looks sequential
and there are no races.
It seems to me if it was
static struct prog_test_ref_kfunc prog_test_struct = {..};
and none of [bpf_]this_cpu_ptr()
the test would work the same way.
What am I missing?
