On Wed, May 14, 2025 at 2:00 PM Song Liu song@kernel.org wrote:
On Tue, May 13, 2025 at 9:36 AM T.J. Mercier tjmercier@google.com wrote:
Use the same test buffers as the traditional iterator and a new BPF map to verify the test buffers can be found with the open coded dmabuf iterator.
Signed-off-by: T.J. Mercier tjmercier@google.com Acked-by: Christian König christian.koenig@amd.com Acked-by: Song Liu song@kernel.org
.../testing/selftests/bpf/bpf_experimental.h | 5 +++ .../selftests/bpf/prog_tests/dmabuf_iter.c | 41 +++++++++++++++++++ .../testing/selftests/bpf/progs/dmabuf_iter.c | 38 +++++++++++++++++ 3 files changed, 84 insertions(+)
diff --git a/tools/testing/selftests/bpf/bpf_experimental.h b/tools/testing/selftests/bpf/bpf_experimental.h index 6535c8ae3c46..5e512a1d09d1 100644 --- a/tools/testing/selftests/bpf/bpf_experimental.h +++ b/tools/testing/selftests/bpf/bpf_experimental.h @@ -591,4 +591,9 @@ extern int bpf_iter_kmem_cache_new(struct bpf_iter_kmem_cache *it) __weak __ksym extern struct kmem_cache *bpf_iter_kmem_cache_next(struct bpf_iter_kmem_cache *it) __weak __ksym; extern void bpf_iter_kmem_cache_destroy(struct bpf_iter_kmem_cache *it) __weak __ksym;
+struct bpf_iter_dmabuf; +extern int bpf_iter_dmabuf_new(struct bpf_iter_dmabuf *it) __weak __ksym; +extern struct dma_buf *bpf_iter_dmabuf_next(struct bpf_iter_dmabuf *it) __weak __ksym; +extern void bpf_iter_dmabuf_destroy(struct bpf_iter_dmabuf *it) __weak __ksym;
#endif diff --git a/tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c b/tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c index dc740bd0e2bd..6c2b0c3dbcd8 100644 --- a/tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c +++ b/tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c @@ -219,14 +219,52 @@ static void subtest_dmabuf_iter_check_default_iter(struct dmabuf_iter *skel) close(iter_fd); }
+static void subtest_dmabuf_iter_check_open_coded(struct dmabuf_iter *skel, int map_fd) +{
LIBBPF_OPTS(bpf_test_run_opts, topts);char key[DMA_BUF_NAME_LEN];int err, fd;bool found;/* No need to attach it, just run it directly */fd = bpf_program__fd(skel->progs.iter_dmabuf_for_each);err = bpf_prog_test_run_opts(fd, &topts);if (!ASSERT_OK(err, "test_run_opts err"))return;if (!ASSERT_OK(topts.retval, "test_run_opts retval"))return;if (!ASSERT_OK(bpf_map_get_next_key(map_fd, NULL, key), "get next key"))return;do {ASSERT_OK(bpf_map_lookup_elem(map_fd, key, &found), "lookup");ASSERT_TRUE(found, "found test buffer");This check failed once in the CI, on s390:
Error: #89/3 dmabuf_iter/open_coded 9309 subtest_dmabuf_iter_check_open_coded:PASS:test_run_opts err 0 nsec 9310 subtest_dmabuf_iter_check_open_coded:PASS:test_run_opts retval 0 nsec 9311 subtest_dmabuf_iter_check_open_coded:PASS:get next key 0 nsec 9312 subtest_dmabuf_iter_check_open_coded:PASS:lookup 0 nsec 9313 subtest_dmabuf_iter_check_open_coded:FAIL:found test buffer unexpected found test buffer: got FALSE
But it passed in the rerun. It is probably a bit flakey. Maybe we need some barrier somewhere.
Here is the failure:
https://github.com/kernel-patches/bpf/actions/runs/15002058808/job/422348647...
To see the log, you need to log in GitHub.
Thanks, Song
Thanks, yeah I have been trying to run this locally today but still working on setting up an environment for it. Daniel Xu thoughtfully suggested I use a github PR to trigger CI, but I tried that last week without success: https://github.com/kernel-patches/bpf/pull/8910
I'm not sure if this is the cause (doesn't show up on the runs that pass) but I have no idea why that would be intermittently failing: libbpf: Error in bpf_create_map_xattr(testbuf_hash): -EINVAL. Retrying without BTF.
} while (bpf_map_get_next_key(map_fd, key, key));+}
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