The closing parentheses around the read syscall is misplaced, causing
single byte reads from the iterator instead of buf sized reads. While
the end result is the same, many more read calls than necessary are
performed.
$ tools/testing/selftests/bpf/vmtest.sh "./test_progs -t kmem_cache_iter"
145/1 kmem_cache_iter/check_task_struct:OK
145/2 kmem_cache_iter/check_slabinfo:OK
145/3 kmem_cache_iter/open_coded_iter:OK
145 kmem_cache_iter:OK
Summary: 1/3 PASSED, 0 SKIPPED, 0 FAILED
Fixes: a496d0cdc8 ("selftests/bpf: Add a test for kmem_cache_iter")
Signed-off-by: T.J. Mercier <tjmercier@google.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://patch.msgid.link/20250428180256.1482899-1-tjmercier@google.com
The new subtest runs with bpf_prog_test_run_opts() as a syscall prog.
It iterates the kmem_cache using bpf_for_each loop and count the number
of entries. Finally it checks it with the number of entries from the
regular iterator.
$ ./vmtest.sh -- ./test_progs -t kmem_cache_iter
...
#130/1 kmem_cache_iter/check_task_struct:OK
#130/2 kmem_cache_iter/check_slabinfo:OK
#130/3 kmem_cache_iter/open_coded_iter:OK
#130 kmem_cache_iter:OK
Summary: 1/3 PASSED, 0 SKIPPED, 0 FAILED
Also simplify the code by using attach routine of the skeleton.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20241030222819.1800667-2-namhyung@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The test traverses all slab caches using the kmem_cache_iter and save
the data into slab_result array map. And check if current task's
pointer is from "task_struct" slab cache using bpf_get_kmem_cache().
Also compare the result array with /proc/slabinfo if available (when
CONFIG_SLUB_DEBUG is on). Note that many of the fields in the slabinfo
are transient, so it only compares the name and objsize fields.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20241010232505.1339892-4-namhyung@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
T.J. Mercier
Namhyung Kim