tools/testing/selftests/resctrl/cat_test.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Cache Allocation Technology (CAT) test
   4  *
   5  * Copyright (C) 2018 Intel Corporation
   6  *
   7  * Authors:
   8  *    Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
   9  *    Fenghua Yu <fenghua.yu@intel.com>
  10  */
  11 #include "resctrl.h"
  12 #include <unistd.h>
  13
  14 #define RESULT_FILE_NAME1       "result_cat1"
  15 #define RESULT_FILE_NAME2       "result_cat2"
  16 #define NUM_OF_RUNS             5
  17 #define MAX_DIFF_PERCENT        4
  18 #define MAX_DIFF                1000000
  19
  20 int count_of_bits;
  21 char cbm_mask[256];
  22 unsigned long long_mask;
  23 unsigned long cache_size;
  24
  25 /*
  26  * Change schemata. Write schemata to specified
  27  * con_mon grp, mon_grp in resctrl FS.
  28  * Run 5 times in order to get average values.
  29  */
  30 static int cat_setup(int num, ...)
  31 {
  32         struct resctrl_val_param *p;
  33         char schemata[64];
  34         va_list param;
  35         int ret = 0;
  36
  37         va_start(param, num);
  38         p = va_arg(param, struct resctrl_val_param *);
  39         va_end(param);
  40
  41         /* Run NUM_OF_RUNS times */
  42         if (p->num_of_runs >= NUM_OF_RUNS)
  43                 return -1;
  44
  45         if (p->num_of_runs == 0) {
  46                 sprintf(schemata, "%lx", p->mask);
  47                 ret = write_schemata(p->ctrlgrp, schemata, p->cpu_no,
  48                                      p->resctrl_val);
  49         }
  50         p->num_of_runs++;
  51
  52         return ret;
  53 }
  54
  55 static void show_cache_info(unsigned long sum_llc_perf_miss, int no_of_bits,
  56                             unsigned long span)
  57 {
  58         unsigned long allocated_cache_lines = span / 64;
  59         unsigned long avg_llc_perf_miss = 0;
  60         float diff_percent;
  61
  62         avg_llc_perf_miss = sum_llc_perf_miss / (NUM_OF_RUNS - 1);
  63         diff_percent = ((float)allocated_cache_lines - avg_llc_perf_miss) /
  64                                 allocated_cache_lines * 100;
  65
  66         printf("%sok CAT: cache miss rate within %d%%\n",
  67                !is_amd && abs((int)diff_percent) > MAX_DIFF_PERCENT ?
  68                "not " : "", MAX_DIFF_PERCENT);
  69         tests_run++;
  70         printf("# Percent diff=%d\n", abs((int)diff_percent));
  71         printf("# Number of bits: %d\n", no_of_bits);
  72         printf("# Avg_llc_perf_miss: %lu\n", avg_llc_perf_miss);
  73         printf("# Allocated cache lines: %lu\n", allocated_cache_lines);
  74 }
  75
  76 static int check_results(struct resctrl_val_param *param)
  77 {
  78         char *token_array[8], temp[512];
  79         unsigned long sum_llc_perf_miss = 0;
  80         int runs = 0, no_of_bits = 0;
  81         FILE *fp;
  82
  83         printf("# Checking for pass/fail\n");
  84         fp = fopen(param->filename, "r");
  85         if (!fp) {
  86                 perror("# Cannot open file");
  87
  88                 return errno;
  89         }
  90
  91         while (fgets(temp, sizeof(temp), fp)) {
  92                 char *token = strtok(temp, ":\t");
  93                 int fields = 0;
  94
  95                 while (token) {
  96                         token_array[fields++] = token;
  97                         token = strtok(NULL, ":\t");
  98                 }
  99                 /*
 100                  * Discard the first value which is inaccurate due to monitoring
 101                  * setup transition phase.
 102                  */
 103                 if (runs > 0)
 104                         sum_llc_perf_miss += strtoul(token_array[3], NULL, 0);
 105                 runs++;
 106         }
 107
 108         fclose(fp);
 109         no_of_bits = count_bits(param->mask);
 110
 111         show_cache_info(sum_llc_perf_miss, no_of_bits, param->span);
 112
 113         return 0;
 114 }
 115
 116 void cat_test_cleanup(void)
 117 {
 118         remove(RESULT_FILE_NAME1);
 119         remove(RESULT_FILE_NAME2);
 120 }
 121
 122 int cat_perf_miss_val(int cpu_no, int n, char *cache_type)
 123 {
 124         unsigned long l_mask, l_mask_1;
 125         int ret, pipefd[2], sibling_cpu_no;
 126         char pipe_message;
 127         pid_t bm_pid;
 128
 129         cache_size = 0;
 130
 131         ret = remount_resctrlfs(true);
 132         if (ret)
 133                 return ret;
 134
 135         if (!validate_resctrl_feature_request("cat"))
 136                 return -1;
 137
 138         /* Get default cbm mask for L3/L2 cache */
 139         ret = get_cbm_mask(cache_type);
 140         if (ret)
 141                 return ret;
 142
 143         long_mask = strtoul(cbm_mask, NULL, 16);
 144
 145         /* Get L3/L2 cache size */
 146         ret = get_cache_size(cpu_no, cache_type, &cache_size);
 147         if (ret)
 148                 return ret;
 149         printf("cache size :%lu\n", cache_size);
 150
 151         /* Get max number of bits from default-cabm mask */
 152         count_of_bits = count_bits(long_mask);
 153
 154         if (n < 1 || n > count_of_bits - 1) {
 155                 printf("Invalid input value for no_of_bits n!\n");
 156                 printf("Please Enter value in range 1 to %d\n",
 157                        count_of_bits - 1);
 158                 return -1;
 159         }
 160
 161         /* Get core id from same socket for running another thread */
 162         sibling_cpu_no = get_core_sibling(cpu_no);
 163         if (sibling_cpu_no < 0)
 164                 return -1;
 165
 166         struct resctrl_val_param param = {
 167                 .resctrl_val    = "cat",
 168                 .cpu_no         = cpu_no,
 169                 .mum_resctrlfs  = 0,
 170                 .setup          = cat_setup,
 171         };
 172
 173         l_mask = long_mask >> n;
 174         l_mask_1 = ~l_mask & long_mask;
 175
 176         /* Set param values for parent thread which will be allocated bitmask
 177          * with (max_bits - n) bits
 178          */
 179         param.span = cache_size * (count_of_bits - n) / count_of_bits;
 180         strcpy(param.ctrlgrp, "c2");
 181         strcpy(param.mongrp, "m2");
 182         strcpy(param.filename, RESULT_FILE_NAME2);
 183         param.mask = l_mask;
 184         param.num_of_runs = 0;
 185
 186         if (pipe(pipefd)) {
 187                 perror("# Unable to create pipe");
 188                 return errno;
 189         }
 190
 191         bm_pid = fork();
 192
 193         /* Set param values for child thread which will be allocated bitmask
 194          * with n bits
 195          */
 196         if (bm_pid == 0) {
 197                 param.mask = l_mask_1;
 198                 strcpy(param.ctrlgrp, "c1");
 199                 strcpy(param.mongrp, "m1");
 200                 param.span = cache_size * n / count_of_bits;
 201                 strcpy(param.filename, RESULT_FILE_NAME1);
 202                 param.num_of_runs = 0;
 203                 param.cpu_no = sibling_cpu_no;
 204         }
 205
 206         remove(param.filename);
 207
 208         ret = cat_val(&param);
 209         if (ret)
 210                 return ret;
 211
 212         ret = check_results(&param);
 213         if (ret)
 214                 return ret;
 215
 216         if (bm_pid == 0) {
 217                 /* Tell parent that child is ready */
 218                 close(pipefd[0]);
 219                 pipe_message = 1;
 220                 if (write(pipefd[1], &pipe_message, sizeof(pipe_message)) <
 221                     sizeof(pipe_message)) {
 222                         close(pipefd[1]);
 223                         perror("# failed signaling parent process");
 224                         return errno;
 225                 }
 226
 227                 close(pipefd[1]);
 228                 while (1)
 229                         ;
 230         } else {
 231                 /* Parent waits for child to be ready. */
 232                 close(pipefd[1]);
 233                 pipe_message = 0;
 234                 while (pipe_message != 1) {
 235                         if (read(pipefd[0], &pipe_message,
 236                                  sizeof(pipe_message)) < sizeof(pipe_message)) {
 237                                 perror("# failed reading from child process");
 238                                 break;
 239                         }
 240                 }
 241                 close(pipefd[0]);
 242                 kill(bm_pid, SIGKILL);
 243         }
 244
 245         cat_test_cleanup();
 246         if (bm_pid)
 247                 umount_resctrlfs();
 248
 249         return 0;
 250 }