From: Rakesh Kudurumalla <[email protected]> Improve test_pmu error handling to distinguish between different failure scenarios based on rte_pmu_init() return codes.
Changes: - Handle -ENODEV (no hardware) -> return TEST_SKIPPED This is not a test failure, just missing hardware - Handle -EACCES (permission denied) -> return TEST_FAILED This indicates a configuration issue that user must fix Provide helpful hint about adjusting perf_event_paranoid - Handle other errors -> return TEST_FAILED Unexpected errors should fail the test - Add error checking for rte_pmu_add_event() Print event name if addition fails Properly cleanup with rte_pmu_fini() - Check if PMU counter returned zero Print message to help diagnose the issue - Re-enable the test by adding REGISTER_FAST_TEST() Test was previously disabled due to failures With improved error handling, failures can be properly diagnosed This makes test results more informative: - TEST_SKIPPED: No PMU hardware (expected on some platforms) - TEST_FAILED: Configuration issue or real bug (requires action) - TEST_SUCCESS: PMU working correctly Signed-off-by: Rakesh Kudurumalla <[email protected]> --- app/test/test_pmu.c | 74 +++++++++++++++------------------------------ 1 file changed, 25 insertions(+), 49 deletions(-) diff --git a/app/test/test_pmu.c b/app/test/test_pmu.c index a73594d73d..d1ec68e428 100644 --- a/app/test/test_pmu.c +++ b/app/test/test_pmu.c @@ -2,53 +2,18 @@ * Copyright(C) 2025 Marvell International Ltd. */ -#include <stdbool.h> +#include <errno.h> #include <stdio.h> -#include <sys/types.h> -#include <unistd.h> #include <rte_pmu.h> #include "test.h" -#define PERF_EVENT_PARANOID_PATH "/proc/sys/kernel/perf_event_paranoid" - -static bool perf_allowed_quirk(void) -{ - int level, ret; - FILE *fp; - - fp = fopen(PERF_EVENT_PARANOID_PATH, "r"); - if (!fp) - return false; - - ret = fscanf(fp, "%d", &level); - fclose(fp); - if (ret != 1) - return false; - - /* On vanilla Linux the default perf_event_paranoid level is 2, which allows non-privileged - * processes to access performance counters. - * - * Debian / Ubuntu and their derivatives apply patches that introduce - * additional paranoia levels: - * - * - Debian adds level 3, which restricts access to perf_event_open() for - * monitoring other processes, but still allows unprivileged self-monitoring. - * See: https://lore.kernel.org/all/[email protected]/ - * - Ubuntu adds level 4 (which is also the default), completely disabling perf_event_open() - * for unprivileged users???effectively disabling self-monitoring. - * - * That said, check below should be sufficient to enable this test on most kernels. - */ - return level < 4; -} - static int test_pmu_read(void) { const char *name = NULL; - int tries = 10, event; + int ret, tries = 10, event; uint64_t val = 0; #if defined(RTE_ARCH_ARM64) @@ -62,28 +27,39 @@ test_pmu_read(void) return TEST_SKIPPED; } - if ((getuid() != 0) && !perf_allowed_quirk()) { - printf("self-monitoring disabled\n"); + ret = rte_pmu_init(); + if (ret == -ENODEV) { + printf("PMU hardware not available or kernel lacks PMU support\n"); return TEST_SKIPPED; } - - if (rte_pmu_init() < 0) { - printf("PMU not initialized\n"); - return TEST_SKIPPED; + if (ret == -EACCES) { + printf("Insufficient privileges for PMU access\n"); + printf("Try: echo 0 | sudo tee /proc/sys/kernel/perf_event_paranoid\n"); + return TEST_FAILED; + } + if (ret < 0) { + printf("PMU initialization failed: %d\n", ret); + return TEST_FAILED; } event = rte_pmu_add_event(name); + if (event < 0) { + printf("Failed to add event '%s': %d\n", name, event); + rte_pmu_fini(); + return TEST_FAILED; + } + while (tries--) val += rte_pmu_read(event); rte_pmu_fini(); - /* rte_pmu_read() returns zero if it can't read perf counter. Thus series of zeros doesn't - * necessarily mean the counter is actually zero. It might just signal a problem with setup - * itself. So skip test to avoid testing failure and leave it to user to interpret this - * outcome. - */ - return val ? TEST_SUCCESS : TEST_SKIPPED; + if (val == 0) { + printf("PMU counter read returned zero\n"); + return TEST_FAILED; + } + + return TEST_SUCCESS; } static struct unit_test_suite pmu_tests = { -- 2.25.1
