190 lines · c
1// SPDX-License-Identifier: GPL-2.02 3#include <stdint.h>4#include "resctrl.h"5 6char llc_occup_path[1024];7 8void perf_event_attr_initialize(struct perf_event_attr *pea, __u64 config)9{10 memset(pea, 0, sizeof(*pea));11 pea->type = PERF_TYPE_HARDWARE;12 pea->size = sizeof(*pea);13 pea->read_format = PERF_FORMAT_GROUP;14 pea->exclude_kernel = 1;15 pea->exclude_hv = 1;16 pea->exclude_idle = 1;17 pea->exclude_callchain_kernel = 1;18 pea->inherit = 1;19 pea->exclude_guest = 1;20 pea->disabled = 1;21 pea->config = config;22}23 24/* Start counters to log values */25int perf_event_reset_enable(int pe_fd)26{27 int ret;28 29 ret = ioctl(pe_fd, PERF_EVENT_IOC_RESET, 0);30 if (ret < 0)31 return ret;32 33 ret = ioctl(pe_fd, PERF_EVENT_IOC_ENABLE, 0);34 if (ret < 0)35 return ret;36 37 return 0;38}39 40void perf_event_initialize_read_format(struct perf_event_read *pe_read)41{42 memset(pe_read, 0, sizeof(*pe_read));43 pe_read->nr = 1;44}45 46int perf_open(struct perf_event_attr *pea, pid_t pid, int cpu_no)47{48 int pe_fd;49 50 pe_fd = perf_event_open(pea, pid, cpu_no, -1, PERF_FLAG_FD_CLOEXEC);51 if (pe_fd == -1) {52 ksft_perror("Error opening leader");53 return -1;54 }55 56 perf_event_reset_enable(pe_fd);57 58 return pe_fd;59}60 61/*62 * Get LLC Occupancy as reported by RESCTRL FS63 * For CMT,64 * 1. If con_mon grp and mon grp given, then read from mon grp in65 * con_mon grp66 * 2. If only con_mon grp given, then read from con_mon grp67 * 3. If both not given, then read from root con_mon grp68 * For CAT,69 * 1. If con_mon grp given, then read from it70 * 2. If con_mon grp not given, then read from root con_mon grp71 *72 * Return: =0 on success. <0 on failure.73 */74static int get_llc_occu_resctrl(unsigned long *llc_occupancy)75{76 FILE *fp;77 78 fp = fopen(llc_occup_path, "r");79 if (!fp) {80 ksft_perror("Failed to open results file");81 82 return -1;83 }84 if (fscanf(fp, "%lu", llc_occupancy) <= 0) {85 ksft_perror("Could not get llc occupancy");86 fclose(fp);87 88 return -1;89 }90 fclose(fp);91 92 return 0;93}94 95/*96 * print_results_cache: the cache results are stored in a file97 * @filename: file that stores the results98 * @bm_pid: child pid that runs benchmark99 * @llc_value: perf miss value /100 * llc occupancy value reported by resctrl FS101 *102 * Return: 0 on success, < 0 on error.103 */104static int print_results_cache(const char *filename, pid_t bm_pid, __u64 llc_value)105{106 FILE *fp;107 108 if (strcmp(filename, "stdio") == 0 || strcmp(filename, "stderr") == 0) {109 printf("Pid: %d \t LLC_value: %llu\n", (int)bm_pid, llc_value);110 } else {111 fp = fopen(filename, "a");112 if (!fp) {113 ksft_perror("Cannot open results file");114 115 return -1;116 }117 fprintf(fp, "Pid: %d \t llc_value: %llu\n", (int)bm_pid, llc_value);118 fclose(fp);119 }120 121 return 0;122}123 124/*125 * perf_event_measure - Measure perf events126 * @filename: Filename for writing the results127 * @bm_pid: PID that runs the benchmark128 *129 * Measures perf events (e.g., cache misses) and writes the results into130 * @filename. @bm_pid is written to the results file along with the measured131 * value.132 *133 * Return: =0 on success. <0 on failure.134 */135int perf_event_measure(int pe_fd, struct perf_event_read *pe_read,136 const char *filename, pid_t bm_pid)137{138 int ret;139 140 /* Stop counters after one span to get miss rate */141 ret = ioctl(pe_fd, PERF_EVENT_IOC_DISABLE, 0);142 if (ret < 0)143 return ret;144 145 ret = read(pe_fd, pe_read, sizeof(*pe_read));146 if (ret == -1) {147 ksft_perror("Could not get perf value");148 return -1;149 }150 151 return print_results_cache(filename, bm_pid, pe_read->values[0].value);152}153 154/*155 * measure_llc_resctrl - Measure resctrl LLC value from resctrl156 * @filename: Filename for writing the results157 * @bm_pid: PID that runs the benchmark158 *159 * Measures LLC occupancy from resctrl and writes the results into @filename.160 * @bm_pid is written to the results file along with the measured value.161 *162 * Return: =0 on success. <0 on failure.163 */164int measure_llc_resctrl(const char *filename, pid_t bm_pid)165{166 unsigned long llc_occu_resc = 0;167 int ret;168 169 ret = get_llc_occu_resctrl(&llc_occu_resc);170 if (ret < 0)171 return ret;172 173 return print_results_cache(filename, bm_pid, llc_occu_resc);174}175 176/*177 * show_cache_info - Show generic cache test information178 * @no_of_bits: Number of bits179 * @avg_llc_val: Average of LLC cache result data180 * @cache_span: Cache span181 * @lines: @cache_span in lines or bytes182 */183void show_cache_info(int no_of_bits, __u64 avg_llc_val, size_t cache_span, bool lines)184{185 ksft_print_msg("Number of bits: %d\n", no_of_bits);186 ksft_print_msg("Average LLC val: %llu\n", avg_llc_val);187 ksft_print_msg("Cache span (%s): %zu\n", lines ? "lines" : "bytes",188 cache_span);189}190