129 lines · c
1// SPDX-License-Identifier: GPL-2.02#include "tests/tests.h"3#include "cloexec.h"4#include "debug.h"5#include "evlist.h"6#include "evsel.h"7#include "arch-tests.h"8#include <internal/lib.h> // page_size9 10#include <signal.h>11#include <sys/mman.h>12#include <sys/wait.h>13#include <errno.h>14#include <string.h>15 16static pid_t spawn(void)17{18 pid_t pid;19 20 pid = fork();21 if (pid)22 return pid;23 24 while(1)25 sleep(5);26 return 0;27}28 29/*30 * Create an event group that contains both a sampled hardware31 * (cpu-cycles) and software (intel_cqm/llc_occupancy/) event. We then32 * wait for the hardware perf counter to overflow and generate a PMI,33 * which triggers an event read for both of the events in the group.34 *35 * Since reading Intel CQM event counters requires sending SMP IPIs, the36 * CQM pmu needs to handle the above situation gracefully, and return37 * the last read counter value to avoid triggering a WARN_ON_ONCE() in38 * smp_call_function_many() caused by sending IPIs from NMI context.39 */40int test__intel_cqm_count_nmi_context(struct test_suite *test __maybe_unused, int subtest __maybe_unused)41{42 struct evlist *evlist = NULL;43 struct evsel *evsel = NULL;44 struct perf_event_attr pe;45 int i, fd[2], flag, ret;46 size_t mmap_len;47 void *event;48 pid_t pid;49 int err = TEST_FAIL;50 51 flag = perf_event_open_cloexec_flag();52 53 evlist = evlist__new();54 if (!evlist) {55 pr_debug("evlist__new failed\n");56 return TEST_FAIL;57 }58 59 ret = parse_event(evlist, "intel_cqm/llc_occupancy/");60 if (ret) {61 pr_debug("parse_events failed, is \"intel_cqm/llc_occupancy/\" available?\n");62 err = TEST_SKIP;63 goto out;64 }65 66 evsel = evlist__first(evlist);67 if (!evsel) {68 pr_debug("evlist__first failed\n");69 goto out;70 }71 72 memset(&pe, 0, sizeof(pe));73 pe.size = sizeof(pe);74 75 pe.type = PERF_TYPE_HARDWARE;76 pe.config = PERF_COUNT_HW_CPU_CYCLES;77 pe.read_format = PERF_FORMAT_GROUP;78 79 pe.sample_period = 128;80 pe.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_READ;81 82 pid = spawn();83 84 fd[0] = sys_perf_event_open(&pe, pid, -1, -1, flag);85 if (fd[0] < 0) {86 pr_debug("failed to open event\n");87 goto out;88 }89 90 memset(&pe, 0, sizeof(pe));91 pe.size = sizeof(pe);92 93 pe.type = evsel->attr.type;94 pe.config = evsel->attr.config;95 96 fd[1] = sys_perf_event_open(&pe, pid, -1, fd[0], flag);97 if (fd[1] < 0) {98 pr_debug("failed to open event\n");99 goto out;100 }101 102 /*103 * Pick a power-of-two number of pages + 1 for the meta-data104 * page (struct perf_event_mmap_page). See tools/perf/design.txt.105 */106 mmap_len = page_size * 65;107 108 event = mmap(NULL, mmap_len, PROT_READ, MAP_SHARED, fd[0], 0);109 if (event == (void *)(-1)) {110 pr_debug("failed to mmap %d\n", errno);111 goto out;112 }113 114 sleep(1);115 116 err = TEST_OK;117 118 munmap(event, mmap_len);119 120 for (i = 0; i < 2; i++)121 close(fd[i]);122 123 kill(pid, SIGKILL);124 wait(NULL);125out:126 evlist__delete(evlist);127 return err;128}129