mirror of
https://github.com/cirosantilli/linux-kernel-module-cheat.git
synced 2026-01-23 10:15:57 +01:00
104 lines
2.9 KiB
C
104 lines
2.9 KiB
C
/* https://cirosantilli.com/linux-kernel-module-cheat#perf-event-open
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* Adapted from `man perf_event_open` in manpages 5.05-1. */
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#include <asm/unistd.h>
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#include <linux/perf_event.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/ioctl.h>
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#include <unistd.h>
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#define LKMC_M5OPS_ENABLE 1
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#include <lkmc.h>
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static long perf_event_open(struct perf_event_attr *hw_event,
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uint32_t type, uint64_t config, pid_t pid,
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int cpu, int group_fd, unsigned long flags
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) {
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int ret;
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memset(hw_event, 0, sizeof(struct perf_event_attr));
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hw_event->type = type;
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hw_event->size = sizeof(struct perf_event_attr);
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hw_event->config = config;
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hw_event->disabled = 1;
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hw_event->exclude_kernel = 1;
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/* Don't count hypervisor events. */
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hw_event->exclude_hv = 1;
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ret = syscall(__NR_perf_event_open, hw_event, pid, cpu,
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group_fd, flags);
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if (ret == -1) {
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fprintf(stderr, "Error opening leader %llx\n", hw_event->config);
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exit(EXIT_FAILURE);
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}
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return ret;
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}
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typedef struct {
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char *name;
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uint32_t type;
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uint64_t config;
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} Desc;
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#define DESC(type,config) {#config, type, config}
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int
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main(int argc, char **argv) {
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size_t i;
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int gem5;
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long long count;
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uint64_t n;
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Desc descs[] = {
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DESC(PERF_TYPE_HARDWARE, PERF_COUNT_HW_BRANCH_INSTRUCTIONS),
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DESC(PERF_TYPE_HARDWARE, PERF_COUNT_HW_BRANCH_MISSES),
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DESC(PERF_TYPE_HARDWARE, PERF_COUNT_HW_CPU_CYCLES),
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DESC(PERF_TYPE_HARDWARE, PERF_COUNT_HW_INSTRUCTIONS),
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DESC(PERF_TYPE_HW_CACHE, PERF_COUNT_HW_CACHE_L1D | PERF_COUNT_HW_CACHE_OP_READ << 8 | PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
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};
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struct perf_event_attr pes[LKMC_ARRAY_SIZE(descs)];
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int fds[LKMC_ARRAY_SIZE(descs)];
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if (argc > 1) {
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n = strtoll(argv[1], NULL, 0);
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} else {
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n = 10000;
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}
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if (argc > 2) {
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gem5 = argv[2][0] == '1';
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} else {
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gem5 = 0;
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}
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for (i = 0; i < LKMC_ARRAY_SIZE(descs); i++)
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fds[i] = perf_event_open(&pes[i],
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descs[i].type, descs[i].config, 0, -1, -1, 0);
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/* Start the counts. */
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for (i = 0; i < LKMC_ARRAY_SIZE(descs); i++)
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ioctl(fds[i], PERF_EVENT_IOC_RESET, 0);
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for (i = 0; i < LKMC_ARRAY_SIZE(descs); i++)
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ioctl(fds[i], PERF_EVENT_IOC_ENABLE, 0);
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if (gem5) {
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/* Cross check with gem5 stats to see if things make sense.. */
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LKMC_M5OPS_RESETSTATS;
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}
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/* Mesure this function. */
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lkmc_busy_loop(n, 1);
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/* Stop the count. */
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if (gem5) { LKMC_M5OPS_DUMPSTATS; }
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for (i = 0; i < LKMC_ARRAY_SIZE(descs); i++)
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ioctl(fds[i], PERF_EVENT_IOC_DISABLE, 0);
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/* Print results. */
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for (i = 0; i < LKMC_ARRAY_SIZE(descs); i++) {
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read(fds[i], &count, sizeof(long long));
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printf("%s %lld\n", descs[i].name, count);
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}
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for (i = 0; i < LKMC_ARRAY_SIZE(descs); i++)
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close(fds[i]);
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}
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