On Sat, Apr 06, 2024 at 10:52:10AM -0700, Andrii Nakryiko wrote:
On Sat, Apr 6, 2024 at 10:39 AM Andrii Nakryiko andrii.nakryiko@gmail.com wrote:
On Sat, Apr 6, 2024 at 2:20 AM Andrea Righi andrea.righi@canonical.com wrote:
Add tests for new API ring__consume_n() and ring_buffer__consume_n().
Signed-off-by: Andrea Righi andrea.righi@canonical.com
tools/testing/selftests/bpf/prog_tests/ringbuf.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/tools/testing/selftests/bpf/prog_tests/ringbuf.c b/tools/testing/selftests/bpf/prog_tests/ringbuf.c index 48c5695b7abf..33aba7684ab9 100644 --- a/tools/testing/selftests/bpf/prog_tests/ringbuf.c +++ b/tools/testing/selftests/bpf/prog_tests/ringbuf.c @@ -304,10 +304,18 @@ static void ringbuf_subtest(void) err = ring_buffer__consume(ringbuf); CHECK(err < 0, "rb_consume", "failed: %d\b", err);
/* try to consume up to one item */err = ring_buffer__consume_n(ringbuf, 1);CHECK(err < 0 || err > 1, "rb_consume_n", "failed: %d\b", err);/* also consume using ring__consume to make sure it works the same */ err = ring__consume(ring); ASSERT_GE(err, 0, "ring_consume");/* try to consume up to one item */err = ring__consume_n(ring, 1);CHECK(err < 0 || err > 1, "ring_consume_n", "failed: %d\b", err);Did you actually run this test? There is ring_buffer__consume() and ring__consume() calls right before your added calls, so consume_n will return zero.
I dropped this broken patch. Please send a proper test as a follow up.
Sorry, technically, it's not broken, it just doesn't test much (CHECK conditions confused me, I didn't realize you allow zero initially). We will never consume anything and the result will be zero, which isn't very meaningful.
"Interesting" test would set up things so that we have >1 item in ringbuf and we consume exactly one at a time, because that's the new logic you added.
I think it will be simpler to add a dedicated and simpler ringbuf test for this, where you can specify how many items to submit, and then do a bunch of consume/consume_n invocations, checking exact results.
Plus, please don't add new CHECK() uses, use ASSERT_XXX() ones instead.
I've applied first three patches because they look correct and it's good to setup libbpf 1.5 dev cycle, but please do follow up with a better test. Thanks.
Yeah, sorry, I tried to add a minimal test to the existing one, but I agree that it not very meaningful.
I already have a better dedicated test case for this (https://github.com/arighi/ebpf-maps/blob/libbpf-consume-n/src/main.c#L118), I just need to integrate it in the kselftest properly (and maybe pre-generate more than N records in the ring buffer, so that we can better test if the limit works as expected).
I'll send another patch to add a proper test case.
Thanks for applying the other patches! -Andrea
/* 3 rounds, 2 samples each */ cnt = atomic_xchg(&sample_cnt, 0); CHECK(cnt != 6, "cnt", "exp %d samples, got %d\n", 6, cnt);-- 2.43.0