From 29c1b1238a0d161a5fb163e4c8f2303f00777031 Mon Sep 17 00:00:00 2001 From: Mykola Lysenko Date: Mon, 28 Feb 2022 19:39:07 -0800 Subject: [PATCH] Improve BPF test stability (related to perf events and scheduling) In send_signal, replace sleep with dummy cpu intensive computation to increase probability of child process being scheduled. Add few more asserts. In find_vma, reduce sample_freq as higher values may be rejected in some qemu setups, remove usleep and increase length of cpu intensive computation. In bpf_cookie, perf_link and perf_branches, reduce sample_freq as higher values may be rejected in some qemu setups Signed-off-by: Mykola Lysenko --- .../selftests/bpf/prog_tests/bpf_cookie.c | 2 +- .../testing/selftests/bpf/prog_tests/find_vma.c | 13 ++++++++++--- .../selftests/bpf/prog_tests/perf_branches.c | 4 ++-- .../selftests/bpf/prog_tests/perf_link.c | 2 +- .../selftests/bpf/prog_tests/send_signal.c | 17 ++++++++++------- .../selftests/bpf/progs/test_send_signal_kern.c | 2 +- 6 files changed, 25 insertions(+), 15 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c b/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c index cd10df6cd0fce..0612e79a92812 100644 --- a/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c +++ b/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c @@ -199,7 +199,7 @@ static void pe_subtest(struct test_bpf_cookie *skel) attr.type = PERF_TYPE_SOFTWARE; attr.config = PERF_COUNT_SW_CPU_CLOCK; attr.freq = 1; - attr.sample_freq = 4000; + attr.sample_freq = 1000; pfd = syscall(__NR_perf_event_open, &attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC); if (!ASSERT_GE(pfd, 0, "perf_fd")) goto cleanup; diff --git a/tools/testing/selftests/bpf/prog_tests/find_vma.c b/tools/testing/selftests/bpf/prog_tests/find_vma.c index b74b3c0c555a8..a0b68381cd790 100644 --- a/tools/testing/selftests/bpf/prog_tests/find_vma.c +++ b/tools/testing/selftests/bpf/prog_tests/find_vma.c @@ -30,12 +30,20 @@ static int open_pe(void) attr.type = PERF_TYPE_HARDWARE; attr.config = PERF_COUNT_HW_CPU_CYCLES; attr.freq = 1; - attr.sample_freq = 4000; + attr.sample_freq = 1000; pfd = syscall(__NR_perf_event_open, &attr, 0, -1, -1, PERF_FLAG_FD_CLOEXEC); return pfd >= 0 ? pfd : -errno; } +static bool find_vma_pe_condition(struct find_vma *skel) +{ + return skel->bss->found_vm_exec != 1 || + skel->data->find_addr_ret == -1 || + skel->data->find_zero_ret != 0 || + skel->bss->d_iname[0] == 0; +} + static void test_find_vma_pe(struct find_vma *skel) { struct bpf_link *link = NULL; @@ -57,7 +65,7 @@ static void test_find_vma_pe(struct find_vma *skel) if (!ASSERT_OK_PTR(link, "attach_perf_event")) goto cleanup; - for (i = 0; i < 1000000; ++i) + for (i = 0; i < 1000000000 && find_vma_pe_condition(skel); ++i) ++j; test_and_reset_skel(skel, -EBUSY /* in nmi, irq_work is busy */); @@ -108,7 +116,6 @@ void serial_test_find_vma(void) skel->bss->addr = (__u64)(uintptr_t)test_find_vma_pe; test_find_vma_pe(skel); - usleep(100000); /* allow the irq_work to finish */ test_find_vma_kprobe(skel); find_vma__destroy(skel); diff --git a/tools/testing/selftests/bpf/prog_tests/perf_branches.c b/tools/testing/selftests/bpf/prog_tests/perf_branches.c index 12c4f45cee1a8..bc24f83339d64 100644 --- a/tools/testing/selftests/bpf/prog_tests/perf_branches.c +++ b/tools/testing/selftests/bpf/prog_tests/perf_branches.c @@ -110,7 +110,7 @@ static void test_perf_branches_hw(void) attr.type = PERF_TYPE_HARDWARE; attr.config = PERF_COUNT_HW_CPU_CYCLES; attr.freq = 1; - attr.sample_freq = 4000; + attr.sample_freq = 1000; attr.sample_type = PERF_SAMPLE_BRANCH_STACK; attr.branch_sample_type = PERF_SAMPLE_BRANCH_USER | PERF_SAMPLE_BRANCH_ANY; pfd = syscall(__NR_perf_event_open, &attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC); @@ -151,7 +151,7 @@ static void test_perf_branches_no_hw(void) attr.type = PERF_TYPE_SOFTWARE; attr.config = PERF_COUNT_SW_CPU_CLOCK; attr.freq = 1; - attr.sample_freq = 4000; + attr.sample_freq = 1000; pfd = syscall(__NR_perf_event_open, &attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC); if (CHECK(pfd < 0, "perf_event_open", "err %d\n", pfd)) return; diff --git a/tools/testing/selftests/bpf/prog_tests/perf_link.c b/tools/testing/selftests/bpf/prog_tests/perf_link.c index ede07344f264e..224eba6fef2ee 100644 --- a/tools/testing/selftests/bpf/prog_tests/perf_link.c +++ b/tools/testing/selftests/bpf/prog_tests/perf_link.c @@ -39,7 +39,7 @@ void serial_test_perf_link(void) attr.type = PERF_TYPE_SOFTWARE; attr.config = PERF_COUNT_SW_CPU_CLOCK; attr.freq = 1; - attr.sample_freq = 4000; + attr.sample_freq = 1000; pfd = syscall(__NR_perf_event_open, &attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC); if (!ASSERT_GE(pfd, 0, "perf_fd")) goto cleanup; diff --git a/tools/testing/selftests/bpf/prog_tests/send_signal.c b/tools/testing/selftests/bpf/prog_tests/send_signal.c index 776916b61c406..b1b574c7016ab 100644 --- a/tools/testing/selftests/bpf/prog_tests/send_signal.c +++ b/tools/testing/selftests/bpf/prog_tests/send_signal.c @@ -4,11 +4,11 @@ #include #include "test_send_signal_kern.skel.h" -int sigusr1_received = 0; +static int sigusr1_received; static void sigusr1_handler(int signum) { - sigusr1_received++; + sigusr1_received = 1; } static void test_send_signal_common(struct perf_event_attr *attr, @@ -40,9 +40,10 @@ static void test_send_signal_common(struct perf_event_attr *attr, if (pid == 0) { int old_prio; + volatile int volatile_variable = 0; /* install signal handler and notify parent */ - signal(SIGUSR1, sigusr1_handler); + ASSERT_NEQ(signal(SIGUSR1, sigusr1_handler), SIG_ERR, "signal"); close(pipe_c2p[0]); /* close read */ close(pipe_p2c[1]); /* close write */ @@ -63,9 +64,11 @@ static void test_send_signal_common(struct perf_event_attr *attr, ASSERT_EQ(read(pipe_p2c[0], buf, 1), 1, "pipe_read"); /* wait a little for signal handler */ - sleep(1); + for (int i = 0; i < 100000000 && !sigusr1_received; i++) + volatile_variable /= i + 1; buf[0] = sigusr1_received ? '2' : '0'; + ASSERT_EQ(sigusr1_received, 1, "sigusr1_received"); ASSERT_EQ(write(pipe_c2p[1], buf, 1), 1, "pipe_write"); /* wait for parent notification and exit */ @@ -93,7 +96,7 @@ static void test_send_signal_common(struct perf_event_attr *attr, goto destroy_skel; } } else { - pmu_fd = syscall(__NR_perf_event_open, attr, pid, -1, + pmu_fd = syscall(__NR_perf_event_open, attr, pid, -1 /* cpu */, -1 /* group id */, 0 /* flags */); if (!ASSERT_GE(pmu_fd, 0, "perf_event_open")) { err = -1; @@ -110,9 +113,9 @@ static void test_send_signal_common(struct perf_event_attr *attr, ASSERT_EQ(read(pipe_c2p[0], buf, 1), 1, "pipe_read"); /* trigger the bpf send_signal */ - skel->bss->pid = pid; - skel->bss->sig = SIGUSR1; skel->bss->signal_thread = signal_thread; + skel->bss->sig = SIGUSR1; + skel->bss->pid = pid; /* notify child that bpf program can send_signal now */ ASSERT_EQ(write(pipe_p2c[1], buf, 1), 1, "pipe_write"); diff --git a/tools/testing/selftests/bpf/progs/test_send_signal_kern.c b/tools/testing/selftests/bpf/progs/test_send_signal_kern.c index b4233d3efac2d..92354cd720440 100644 --- a/tools/testing/selftests/bpf/progs/test_send_signal_kern.c +++ b/tools/testing/selftests/bpf/progs/test_send_signal_kern.c @@ -10,7 +10,7 @@ static __always_inline int bpf_send_signal_test(void *ctx) { int ret; - if (status != 0 || sig == 0 || pid == 0) + if (status != 0 || pid == 0) return 0; if ((bpf_get_current_pid_tgid() >> 32) == pid) {