1 // SPDX-License-Identifier: GPL-2.0 2 #include "tests/tests.h" 3 #include "perf.h" 4 #include "cloexec.h" 5 #include "debug.h" 6 #include "evlist.h" 7 #include "evsel.h" 8 #include "arch-tests.h" 9 #include "util.h" 10 11 #include <signal.h> 12 #include <sys/mman.h> 13 #include <sys/wait.h> 14 #include <errno.h> 15 #include <string.h> 16 17 static pid_t spawn(void) 18 { 19 pid_t pid; 20 21 pid = fork(); 22 if (pid) 23 return pid; 24 25 while(1) 26 sleep(5); 27 return 0; 28 } 29 30 /* 31 * Create an event group that contains both a sampled hardware 32 * (cpu-cycles) and software (intel_cqm/llc_occupancy/) event. We then 33 * wait for the hardware perf counter to overflow and generate a PMI, 34 * which triggers an event read for both of the events in the group. 35 * 36 * Since reading Intel CQM event counters requires sending SMP IPIs, the 37 * CQM pmu needs to handle the above situation gracefully, and return 38 * the last read counter value to avoid triggering a WARN_ON_ONCE() in 39 * smp_call_function_many() caused by sending IPIs from NMI context. 40 */ 41 int test__intel_cqm_count_nmi_context(struct test *test __maybe_unused, int subtest __maybe_unused) 42 { 43 struct perf_evlist *evlist = NULL; 44 struct perf_evsel *evsel = NULL; 45 struct perf_event_attr pe; 46 int i, fd[2], flag, ret; 47 size_t mmap_len; 48 void *event; 49 pid_t pid; 50 int err = TEST_FAIL; 51 52 flag = perf_event_open_cloexec_flag(); 53 54 evlist = perf_evlist__new(); 55 if (!evlist) { 56 pr_debug("perf_evlist__new failed\n"); 57 return TEST_FAIL; 58 } 59 60 ret = parse_events(evlist, "intel_cqm/llc_occupancy/", NULL); 61 if (ret) { 62 pr_debug("parse_events failed, is \"intel_cqm/llc_occupancy/\" available?\n"); 63 err = TEST_SKIP; 64 goto out; 65 } 66 67 evsel = perf_evlist__first(evlist); 68 if (!evsel) { 69 pr_debug("perf_evlist__first failed\n"); 70 goto out; 71 } 72 73 memset(&pe, 0, sizeof(pe)); 74 pe.size = sizeof(pe); 75 76 pe.type = PERF_TYPE_HARDWARE; 77 pe.config = PERF_COUNT_HW_CPU_CYCLES; 78 pe.read_format = PERF_FORMAT_GROUP; 79 80 pe.sample_period = 128; 81 pe.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_READ; 82 83 pid = spawn(); 84 85 fd[0] = sys_perf_event_open(&pe, pid, -1, -1, flag); 86 if (fd[0] < 0) { 87 pr_debug("failed to open event\n"); 88 goto out; 89 } 90 91 memset(&pe, 0, sizeof(pe)); 92 pe.size = sizeof(pe); 93 94 pe.type = evsel->attr.type; 95 pe.config = evsel->attr.config; 96 97 fd[1] = sys_perf_event_open(&pe, pid, -1, fd[0], flag); 98 if (fd[1] < 0) { 99 pr_debug("failed to open event\n"); 100 goto out; 101 } 102 103 /* 104 * Pick a power-of-two number of pages + 1 for the meta-data 105 * page (struct perf_event_mmap_page). See tools/perf/design.txt. 106 */ 107 mmap_len = page_size * 65; 108 109 event = mmap(NULL, mmap_len, PROT_READ, MAP_SHARED, fd[0], 0); 110 if (event == (void *)(-1)) { 111 pr_debug("failed to mmap %d\n", errno); 112 goto out; 113 } 114 115 sleep(1); 116 117 err = TEST_OK; 118 119 munmap(event, mmap_len); 120 121 for (i = 0; i < 2; i++) 122 close(fd[i]); 123 124 kill(pid, SIGKILL); 125 wait(NULL); 126 out: 127 perf_evlist__delete(evlist); 128 return err; 129 } 130