On Thu, Apr 25, 2024 at 11:47:07AM -0700, Andrii Nakryiko wrote: > On Thu, Apr 25, 2024 at 7:06 AM Andrea Righi <andrea.righi@xxxxxxxxxxxxx> wrote: > > > > Add a testcase for the ring_buffer__consume_n() API. > > > > The test produces multiple samples in a ring buffer, using a > > sys_getpid() fentry prog, and consumes them from user-space in batches, > > rather than consuming all of them greedily, like ring_buffer__consume() > > does. > > > > Link: https://lore.kernel.org/lkml/CAEf4BzaR4zqUpDmj44KNLdpJ=Tpa97GrvzuzVNO5nM6b7oWd1w@xxxxxxxxxxxxxx > > Signed-off-by: Andrea Righi <andrea.righi@xxxxxxxxxxxxx> > > --- > > tools/testing/selftests/bpf/Makefile | 2 +- > > .../selftests/bpf/prog_tests/ringbuf.c | 64 +++++++++++++++++++ > > .../selftests/bpf/progs/test_ringbuf_n.c | 47 ++++++++++++++ > > 3 files changed, 112 insertions(+), 1 deletion(-) > > create mode 100644 tools/testing/selftests/bpf/progs/test_ringbuf_n.c > > > > ChangeLog v2 -> v3: > > - move skel_n inside ringbuf_n_subtest() > > > > ChangeLog v1 -> v2: > > - replace CHECK() with ASSERT_EQ() > > - fix skel -> skel_n > > - drop unused "seq" field from struct sample > > > > [...] > > > + /* Produce N_TOT_SAMPLES samples in the ring buffer by calling getpid() */ > > + skel_n->bss->value = SAMPLE_VALUE; > > + for (i = 0; i < N_TOT_SAMPLES; i++) > > + syscall(__NR_getpgid); > > + > > + /* Consume all samples from the ring buffer in batches of N_SAMPLES */ > > + for (i = 0; i < N_TOT_SAMPLES; i += err) { > > + err = ring_buffer__consume_n(ringbuf, N_SAMPLES); > > + ASSERT_EQ(err, N_SAMPLES, "rb_consume"); > > if something goes wrong and err is < 0, we might end up with a very > long loop. I changed this to: > > if (!ASSERT_EQ(...)) > goto cleanup_ringbuf; > > to avoid this problem Looks good, tested, just in case, and it works a expected. Thanks! -Andrea > > > + } > > + > > +cleanup_ringbuf: > > + ring_buffer__free(ringbuf); > > +cleanup: > > + test_ringbuf_n_lskel__destroy(skel_n); > > +} > > + > > [...]
