1 // SPDX-License-Identifier: GPL-2.0 2 3 #include <stdint.h> 4 #include "resctrl.h" 5 6 char llc_occup_path[1024]; 7 8 void 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 */ 25 int 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 40 void 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 46 int 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 FS 63 * For CMT, 64 * 1. If con_mon grp and mon grp given, then read from mon grp in 65 * con_mon grp 66 * 2. If only con_mon grp given, then read from con_mon grp 67 * 3. If both not given, then read from root con_mon grp 68 * For CAT, 69 * 1. If con_mon grp given, then read from it 70 * 2. If con_mon grp not given, then read from root con_mon grp 71 * 72 * Return: =0 on success. <0 on failure. 73 */ 74 static 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 file 97 * @filename: file that stores the results 98 * @bm_pid: child pid that runs benchmark 99 * @llc_value: perf miss value / 100 * llc occupancy value reported by resctrl FS 101 * 102 * Return: 0 on success, < 0 on error. 103 */ 104 static 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 events 126 * @filename: Filename for writing the results 127 * @bm_pid: PID that runs the benchmark 128 * 129 * Measures perf events (e.g., cache misses) and writes the results into 130 * @filename. @bm_pid is written to the results file along with the measured 131 * value. 132 * 133 * Return: =0 on success. <0 on failure. 134 */ 135 int 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 resctrl 156 * @filename: Filename for writing the results 157 * @bm_pid: PID that runs the benchmark 158 * 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 */ 164 int 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 information 178 * @no_of_bits: Number of bits 179 * @avg_llc_val: Average of LLC cache result data 180 * @cache_span: Cache span 181 * @lines: @cache_span in lines or bytes 182 */ 183 void 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