From: Song Liu song@kernel.org
[ Upstream commit de6d014a09bf12a9a8959d60c0a1d4a41d394a89 ]
Currently, perf_event sample period in perf_event_stackmap is set too low that the test fails randomly. Fix this by using the max sample frequency, from read_perf_max_sample_freq().
Move read_perf_max_sample_freq() to testing_helpers.c. Replace the CHECK() with if-printf, as CHECK is not available in testing_helpers.c.
Fixes: 1da4864c2b20 ("selftests/bpf: Add callchain_stackid") Signed-off-by: Song Liu song@kernel.org Signed-off-by: Daniel Borkmann daniel@iogearbox.net Link: https://lore.kernel.org/bpf/20230412210423.900851-2-song@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- .../bpf/prog_tests/perf_event_stackmap.c | 3 ++- .../bpf/prog_tests/stacktrace_build_id_nmi.c | 15 -------------- tools/testing/selftests/bpf/testing_helpers.c | 20 +++++++++++++++++++ tools/testing/selftests/bpf/testing_helpers.h | 2 ++ 4 files changed, 24 insertions(+), 16 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/perf_event_stackmap.c b/tools/testing/selftests/bpf/prog_tests/perf_event_stackmap.c index 33144c9432aeb..f4aad35afae16 100644 --- a/tools/testing/selftests/bpf/prog_tests/perf_event_stackmap.c +++ b/tools/testing/selftests/bpf/prog_tests/perf_event_stackmap.c @@ -63,7 +63,8 @@ void test_perf_event_stackmap(void) PERF_SAMPLE_BRANCH_NO_FLAGS | PERF_SAMPLE_BRANCH_NO_CYCLES | PERF_SAMPLE_BRANCH_CALL_STACK, - .sample_period = 5000, + .freq = 1, + .sample_freq = read_perf_max_sample_freq(), .size = sizeof(struct perf_event_attr), }; struct perf_event_stackmap *skel; diff --git a/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c b/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c index f4ea1a215ce4d..704f7f6c3704a 100644 --- a/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c +++ b/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c @@ -2,21 +2,6 @@ #include <test_progs.h> #include "test_stacktrace_build_id.skel.h"
-static __u64 read_perf_max_sample_freq(void) -{ - __u64 sample_freq = 5000; /* fallback to 5000 on error */ - FILE *f; - __u32 duration = 0; - - f = fopen("/proc/sys/kernel/perf_event_max_sample_rate", "r"); - if (f == NULL) - return sample_freq; - CHECK(fscanf(f, "%llu", &sample_freq) != 1, "Get max sample rate", - "return default value: 5000,err %d\n", -errno); - fclose(f); - return sample_freq; -} - void test_stacktrace_build_id_nmi(void) { int control_map_fd, stackid_hmap_fd, stackmap_fd; diff --git a/tools/testing/selftests/bpf/testing_helpers.c b/tools/testing/selftests/bpf/testing_helpers.c index 6c44153755e66..3fe98ffed38a6 100644 --- a/tools/testing/selftests/bpf/testing_helpers.c +++ b/tools/testing/selftests/bpf/testing_helpers.c @@ -229,3 +229,23 @@ int bpf_test_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
return bpf_prog_load(type, NULL, license, insns, insns_cnt, &opts); } + +__u64 read_perf_max_sample_freq(void) +{ + __u64 sample_freq = 5000; /* fallback to 5000 on error */ + FILE *f; + + f = fopen("/proc/sys/kernel/perf_event_max_sample_rate", "r"); + if (f == NULL) { + printf("Failed to open /proc/sys/kernel/perf_event_max_sample_rate: err %d\n" + "return default value: 5000\n", -errno); + return sample_freq; + } + if (fscanf(f, "%llu", &sample_freq) != 1) { + printf("Failed to parse /proc/sys/kernel/perf_event_max_sample_rate: err %d\n" + "return default value: 5000\n", -errno); + } + + fclose(f); + return sample_freq; +} diff --git a/tools/testing/selftests/bpf/testing_helpers.h b/tools/testing/selftests/bpf/testing_helpers.h index 6ec00bf79cb55..eb8790f928e4c 100644 --- a/tools/testing/selftests/bpf/testing_helpers.h +++ b/tools/testing/selftests/bpf/testing_helpers.h @@ -20,3 +20,5 @@ struct test_filter_set; int parse_test_list(const char *s, struct test_filter_set *test_set, bool is_glob_pattern); + +__u64 read_perf_max_sample_freq(void);