1 #include "tests/tests.h" 2 #include "perf.h" 3 #include "cloexec.h" 4 #include "debug.h" 5 #include "evlist.h" 6 #include "evsel.h" 7 #include "arch-tests.h" 8 9 #include <sys/mman.h> 10 #include <string.h> 11 12 static pid_t spawn(void) 13 { 14 pid_t pid; 15 16 pid = fork(); 17 if (pid) 18 return pid; 19 20 while(1); 21 sleep(5); 22 return 0; 23 } 24 25 /* 26 * Create an event group that contains both a sampled hardware 27 * (cpu-cycles) and software (intel_cqm/llc_occupancy/) event. We then 28 * wait for the hardware perf counter to overflow and generate a PMI, 29 * which triggers an event read for both of the events in the group. 30 * 31 * Since reading Intel CQM event counters requires sending SMP IPIs, the 32 * CQM pmu needs to handle the above situation gracefully, and return 33 * the last read counter value to avoid triggering a WARN_ON_ONCE() in 34 * smp_call_function_many() caused by sending IPIs from NMI context. 35 */ 36 int test__intel_cqm_count_nmi_context(void) 37 { 38 struct perf_evlist *evlist = NULL; 39 struct perf_evsel *evsel = NULL; 40 struct perf_event_attr pe; 41 int i, fd[2], flag, ret; 42 size_t mmap_len; 43 void *event; 44 pid_t pid; 45 int err = TEST_FAIL; 46 47 flag = perf_event_open_cloexec_flag(); 48 49 evlist = perf_evlist__new(); 50 if (!evlist) { 51 pr_debug("perf_evlist__new failed\n"); 52 return TEST_FAIL; 53 } 54 55 ret = parse_events(evlist, "intel_cqm/llc_occupancy/", NULL); 56 if (ret) { 57 pr_debug("parse_events failed\n"); 58 err = TEST_SKIP; 59 goto out; 60 } 61 62 evsel = perf_evlist__first(evlist); 63 if (!evsel) { 64 pr_debug("perf_evlist__first failed\n"); 65 goto out; 66 } 67 68 memset(&pe, 0, sizeof(pe)); 69 pe.size = sizeof(pe); 70 71 pe.type = PERF_TYPE_HARDWARE; 72 pe.config = PERF_COUNT_HW_CPU_CYCLES; 73 pe.read_format = PERF_FORMAT_GROUP; 74 75 pe.sample_period = 128; 76 pe.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_READ; 77 78 pid = spawn(); 79 80 fd[0] = sys_perf_event_open(&pe, pid, -1, -1, flag); 81 if (fd[0] < 0) { 82 pr_debug("failed to open event\n"); 83 goto out; 84 } 85 86 memset(&pe, 0, sizeof(pe)); 87 pe.size = sizeof(pe); 88 89 pe.type = evsel->attr.type; 90 pe.config = evsel->attr.config; 91 92 fd[1] = sys_perf_event_open(&pe, pid, -1, fd[0], flag); 93 if (fd[1] < 0) { 94 pr_debug("failed to open event\n"); 95 goto out; 96 } 97 98 /* 99 * Pick a power-of-two number of pages + 1 for the meta-data 100 * page (struct perf_event_mmap_page). See tools/perf/design.txt. 101 */ 102 mmap_len = page_size * 65; 103 104 event = mmap(NULL, mmap_len, PROT_READ, MAP_SHARED, fd[0], 0); 105 if (event == (void *)(-1)) { 106 pr_debug("failed to mmap %d\n", errno); 107 goto out; 108 } 109 110 sleep(1); 111 112 err = TEST_OK; 113 114 munmap(event, mmap_len); 115 116 for (i = 0; i < 2; i++) 117 close(fd[i]); 118 119 kill(pid, SIGKILL); 120 wait(NULL); 121 out: 122 perf_evlist__delete(evlist); 123 return err; 124 } 125