// SPDX-License-Identifier: GPL-2.0 #include "tests/tests.h" #include "perf.h" #include "cloexec.h" #include "debug.h" #include "evlist.h" #include "evsel.h" #include "arch-tests.h" #include "util.h" #include #include #include #include #include static pid_t spawn(void) { pid_t pid; pid = fork(); if (pid) return pid; while(1) sleep(5); return 0; } /* * Create an event group that contains both a sampled hardware * (cpu-cycles) and software (intel_cqm/llc_occupancy/) event. We then * wait for the hardware perf counter to overflow and generate a PMI, * which triggers an event read for both of the events in the group. * * Since reading Intel CQM event counters requires sending SMP IPIs, the * CQM pmu needs to handle the above situation gracefully, and return * the last read counter value to avoid triggering a WARN_ON_ONCE() in * smp_call_function_many() caused by sending IPIs from NMI context. */ int test__intel_cqm_count_nmi_context(struct test *test __maybe_unused, int subtest __maybe_unused) { struct evlist *evlist = NULL; struct evsel *evsel = NULL; struct perf_event_attr pe; int i, fd[2], flag, ret; size_t mmap_len; void *event; pid_t pid; int err = TEST_FAIL; flag = perf_event_open_cloexec_flag(); evlist = perf_evlist__new(); if (!evlist) { pr_debug("perf_evlist__new failed\n"); return TEST_FAIL; } ret = parse_events(evlist, "intel_cqm/llc_occupancy/", NULL); if (ret) { pr_debug("parse_events failed, is \"intel_cqm/llc_occupancy/\" available?\n"); err = TEST_SKIP; goto out; } evsel = perf_evlist__first(evlist); if (!evsel) { pr_debug("perf_evlist__first failed\n"); goto out; } memset(&pe, 0, sizeof(pe)); pe.size = sizeof(pe); pe.type = PERF_TYPE_HARDWARE; pe.config = PERF_COUNT_HW_CPU_CYCLES; pe.read_format = PERF_FORMAT_GROUP; pe.sample_period = 128; pe.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_READ; pid = spawn(); fd[0] = sys_perf_event_open(&pe, pid, -1, -1, flag); if (fd[0] < 0) { pr_debug("failed to open event\n"); goto out; } memset(&pe, 0, sizeof(pe)); pe.size = sizeof(pe); pe.type = evsel->attr.type; pe.config = evsel->attr.config; fd[1] = sys_perf_event_open(&pe, pid, -1, fd[0], flag); if (fd[1] < 0) { pr_debug("failed to open event\n"); goto out; } /* * Pick a power-of-two number of pages + 1 for the meta-data * page (struct perf_event_mmap_page). See tools/perf/design.txt. */ mmap_len = page_size * 65; event = mmap(NULL, mmap_len, PROT_READ, MAP_SHARED, fd[0], 0); if (event == (void *)(-1)) { pr_debug("failed to mmap %d\n", errno); goto out; } sleep(1); err = TEST_OK; munmap(event, mmap_len); for (i = 0; i < 2; i++) close(fd[i]); kill(pid, SIGKILL); wait(NULL); out: perf_evlist__delete(evlist); return err; }