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 static void perf_event_reset_enable(int pe_fd) 26 { 27 ioctl(pe_fd, PERF_EVENT_IOC_RESET, 0); 28 ioctl(pe_fd, PERF_EVENT_IOC_ENABLE, 0); 29 } 30 31 void perf_event_initialize_read_format(struct perf_event_read *pe_read) 32 { 33 memset(pe_read, 0, sizeof(*pe_read)); 34 pe_read->nr = 1; 35 } 36 37 int perf_open(struct perf_event_attr *pea, pid_t pid, int cpu_no) 38 { 39 int pe_fd; 40 41 pe_fd = perf_event_open(pea, pid, cpu_no, -1, PERF_FLAG_FD_CLOEXEC); 42 if (pe_fd == -1) { 43 ksft_perror("Error opening leader"); 44 return -1; 45 } 46 47 perf_event_reset_enable(pe_fd); 48 49 return pe_fd; 50 } 51 52 /* 53 * Get LLC Occupancy as reported by RESCTRL FS 54 * For CMT, 55 * 1. If con_mon grp and mon grp given, then read from mon grp in 56 * con_mon grp 57 * 2. If only con_mon grp given, then read from con_mon grp 58 * 3. If both not given, then read from root con_mon grp 59 * For CAT, 60 * 1. If con_mon grp given, then read from it 61 * 2. If con_mon grp not given, then read from root con_mon grp 62 * 63 * Return: =0 on success. <0 on failure. 64 */ 65 static int get_llc_occu_resctrl(unsigned long *llc_occupancy) 66 { 67 FILE *fp; 68 69 fp = fopen(llc_occup_path, "r"); 70 if (!fp) { 71 ksft_perror("Failed to open results file"); 72 73 return -1; 74 } 75 if (fscanf(fp, "%lu", llc_occupancy) <= 0) { 76 ksft_perror("Could not get llc occupancy"); 77 fclose(fp); 78 79 return -1; 80 } 81 fclose(fp); 82 83 return 0; 84 } 85 86 /* 87 * print_results_cache: the cache results are stored in a file 88 * @filename: file that stores the results 89 * @bm_pid: child pid that runs benchmark 90 * @llc_value: perf miss value / 91 * llc occupancy value reported by resctrl FS 92 * 93 * Return: 0 on success, < 0 on error. 94 */ 95 static int print_results_cache(const char *filename, int bm_pid, __u64 llc_value) 96 { 97 FILE *fp; 98 99 if (strcmp(filename, "stdio") == 0 || strcmp(filename, "stderr") == 0) { 100 printf("Pid: %d \t LLC_value: %llu\n", bm_pid, llc_value); 101 } else { 102 fp = fopen(filename, "a"); 103 if (!fp) { 104 ksft_perror("Cannot open results file"); 105 106 return -1; 107 } 108 fprintf(fp, "Pid: %d \t llc_value: %llu\n", bm_pid, llc_value); 109 fclose(fp); 110 } 111 112 return 0; 113 } 114 115 /* 116 * perf_event_measure - Measure perf events 117 * @filename: Filename for writing the results 118 * @bm_pid: PID that runs the benchmark 119 * 120 * Measures perf events (e.g., cache misses) and writes the results into 121 * @filename. @bm_pid is written to the results file along with the measured 122 * value. 123 * 124 * Return: =0 on success. <0 on failure. 125 */ 126 int perf_event_measure(int pe_fd, struct perf_event_read *pe_read, 127 const char *filename, int bm_pid) 128 { 129 int ret; 130 131 /* Stop counters after one span to get miss rate */ 132 ioctl(pe_fd, PERF_EVENT_IOC_DISABLE, 0); 133 134 ret = read(pe_fd, pe_read, sizeof(*pe_read)); 135 if (ret == -1) { 136 ksft_perror("Could not get perf value"); 137 return -1; 138 } 139 140 return print_results_cache(filename, bm_pid, pe_read->values[0].value); 141 } 142 143 /* 144 * measure_llc_resctrl - Measure resctrl LLC value from resctrl 145 * @filename: Filename for writing the results 146 * @bm_pid: PID that runs the benchmark 147 * 148 * Measures LLC occupancy from resctrl and writes the results into @filename. 149 * @bm_pid is written to the results file along with the measured value. 150 * 151 * Return: =0 on success. <0 on failure. 152 */ 153 int measure_llc_resctrl(const char *filename, int bm_pid) 154 { 155 unsigned long llc_occu_resc = 0; 156 int ret; 157 158 ret = get_llc_occu_resctrl(&llc_occu_resc); 159 if (ret < 0) 160 return ret; 161 162 return print_results_cache(filename, bm_pid, llc_occu_resc); 163 } 164 165 /* 166 * show_cache_info - Show generic cache test information 167 * @no_of_bits: Number of bits 168 * @avg_llc_val: Average of LLC cache result data 169 * @cache_span: Cache span 170 * @lines: @cache_span in lines or bytes 171 */ 172 void show_cache_info(int no_of_bits, __u64 avg_llc_val, size_t cache_span, bool lines) 173 { 174 ksft_print_msg("Number of bits: %d\n", no_of_bits); 175 ksft_print_msg("Average LLC val: %llu\n", avg_llc_val); 176 ksft_print_msg("Cache span (%s): %zu\n", lines ? "lines" : "bytes", 177 cache_span); 178 } 179