selftests/resctrl/cat_test.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Cache Allocation Technology (CAT) test
0004  *
0005  * Copyright (C) 2018 Intel Corporation
0006  *
0007  * Authors:
0008  *    Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
0009  *    Fenghua Yu <fenghua.yu@intel.com>
0010  */
0011 #include "resctrl.h"
0012 #include <unistd.h>
0013
0014 #define RESULT_FILE_NAME1   "result_cat1"
0015 #define RESULT_FILE_NAME2   "result_cat2"
0016 #define NUM_OF_RUNS     5
0017 #define MAX_DIFF_PERCENT    4
0018 #define MAX_DIFF        1000000
0019
0020 static int count_of_bits;
0021 static char cbm_mask[256];
0022 static unsigned long long_mask;
0023 static unsigned long cache_size;
0024
0025 /*
0026  * Change schemata. Write schemata to specified
0027  * con_mon grp, mon_grp in resctrl FS.
0028  * Run 5 times in order to get average values.
0029  */
0030 static int cat_setup(int num, ...)
0031 {
0032     struct resctrl_val_param *p;
0033     char schemata[64];
0034     va_list param;
0035     int ret = 0;
0036
0037     va_start(param, num);
0038     p = va_arg(param, struct resctrl_val_param *);
0039     va_end(param);
0040
0041     /* Run NUM_OF_RUNS times */
0042     if (p->num_of_runs >= NUM_OF_RUNS)
0043         return -1;
0044
0045     if (p->num_of_runs == 0) {
0046         sprintf(schemata, "%lx", p->mask);
0047         ret = write_schemata(p->ctrlgrp, schemata, p->cpu_no,
0048                      p->resctrl_val);
0049     }
0050     p->num_of_runs++;
0051
0052     return ret;
0053 }
0054
0055 static int check_results(struct resctrl_val_param *param)
0056 {
0057     char *token_array[8], temp[512];
0058     unsigned long sum_llc_perf_miss = 0;
0059     int runs = 0, no_of_bits = 0;
0060     FILE *fp;
0061
0062     ksft_print_msg("Checking for pass/fail\n");
0063     fp = fopen(param->filename, "r");
0064     if (!fp) {
0065         perror("# Cannot open file");
0066
0067         return errno;
0068     }
0069
0070     while (fgets(temp, sizeof(temp), fp)) {
0071         char *token = strtok(temp, ":\t");
0072         int fields = 0;
0073
0074         while (token) {
0075             token_array[fields++] = token;
0076             token = strtok(NULL, ":\t");
0077         }
0078         /*
0079          * Discard the first value which is inaccurate due to monitoring
0080          * setup transition phase.
0081          */
0082         if (runs > 0)
0083             sum_llc_perf_miss += strtoul(token_array[3], NULL, 0);
0084         runs++;
0085     }
0086
0087     fclose(fp);
0088     no_of_bits = count_bits(param->mask);
0089
0090     return show_cache_info(sum_llc_perf_miss, no_of_bits, param->span / 64,
0091                    MAX_DIFF, MAX_DIFF_PERCENT, NUM_OF_RUNS,
0092                    get_vendor() == ARCH_INTEL, false);
0093 }
0094
0095 void cat_test_cleanup(void)
0096 {
0097     remove(RESULT_FILE_NAME1);
0098     remove(RESULT_FILE_NAME2);
0099 }
0100
0101 int cat_perf_miss_val(int cpu_no, int n, char *cache_type)
0102 {
0103     unsigned long l_mask, l_mask_1;
0104     int ret, pipefd[2], sibling_cpu_no;
0105     char pipe_message;
0106     pid_t bm_pid;
0107
0108     cache_size = 0;
0109
0110     ret = remount_resctrlfs(true);
0111     if (ret)
0112         return ret;
0113
0114     /* Get default cbm mask for L3/L2 cache */
0115     ret = get_cbm_mask(cache_type, cbm_mask);
0116     if (ret)
0117         return ret;
0118
0119     long_mask = strtoul(cbm_mask, NULL, 16);
0120
0121     /* Get L3/L2 cache size */
0122     ret = get_cache_size(cpu_no, cache_type, &cache_size);
0123     if (ret)
0124         return ret;
0125     ksft_print_msg("Cache size :%lu\n", cache_size);
0126
0127     /* Get max number of bits from default-cabm mask */
0128     count_of_bits = count_bits(long_mask);
0129
0130     if (!n)
0131         n = count_of_bits / 2;
0132
0133     if (n > count_of_bits - 1) {
0134         ksft_print_msg("Invalid input value for no_of_bits n!\n");
0135         ksft_print_msg("Please enter value in range 1 to %d\n",
0136                    count_of_bits - 1);
0137         return -1;
0138     }
0139
0140     /* Get core id from same socket for running another thread */
0141     sibling_cpu_no = get_core_sibling(cpu_no);
0142     if (sibling_cpu_no < 0)
0143         return -1;
0144
0145     struct resctrl_val_param param = {
0146         .resctrl_val    = CAT_STR,
0147         .cpu_no     = cpu_no,
0148         .mum_resctrlfs  = 0,
0149         .setup      = cat_setup,
0150     };
0151
0152     l_mask = long_mask >> n;
0153     l_mask_1 = ~l_mask & long_mask;
0154
0155     /* Set param values for parent thread which will be allocated bitmask
0156      * with (max_bits - n) bits
0157      */
0158     param.span = cache_size * (count_of_bits - n) / count_of_bits;
0159     strcpy(param.ctrlgrp, "c2");
0160     strcpy(param.mongrp, "m2");
0161     strcpy(param.filename, RESULT_FILE_NAME2);
0162     param.mask = l_mask;
0163     param.num_of_runs = 0;
0164
0165     if (pipe(pipefd)) {
0166         perror("# Unable to create pipe");
0167         return errno;
0168     }
0169
0170     bm_pid = fork();
0171
0172     /* Set param values for child thread which will be allocated bitmask
0173      * with n bits
0174      */
0175     if (bm_pid == 0) {
0176         param.mask = l_mask_1;
0177         strcpy(param.ctrlgrp, "c1");
0178         strcpy(param.mongrp, "m1");
0179         param.span = cache_size * n / count_of_bits;
0180         strcpy(param.filename, RESULT_FILE_NAME1);
0181         param.num_of_runs = 0;
0182         param.cpu_no = sibling_cpu_no;
0183     }
0184
0185     remove(param.filename);
0186
0187     ret = cat_val(&param);
0188     if (ret)
0189         return ret;
0190
0191     ret = check_results(&param);
0192     if (ret)
0193         return ret;
0194
0195     if (bm_pid == 0) {
0196         /* Tell parent that child is ready */
0197         close(pipefd[0]);
0198         pipe_message = 1;
0199         if (write(pipefd[1], &pipe_message, sizeof(pipe_message)) <
0200             sizeof(pipe_message)) {
0201             close(pipefd[1]);
0202             perror("# failed signaling parent process");
0203             return errno;
0204         }
0205
0206         close(pipefd[1]);
0207         while (1)
0208             ;
0209     } else {
0210         /* Parent waits for child to be ready. */
0211         close(pipefd[1]);
0212         pipe_message = 0;
0213         while (pipe_message != 1) {
0214             if (read(pipefd[0], &pipe_message,
0215                  sizeof(pipe_message)) < sizeof(pipe_message)) {
0216                 perror("# failed reading from child process");
0217                 break;
0218             }
0219         }
0220         close(pipefd[0]);
0221         kill(bm_pid, SIGKILL);
0222     }
0223
0224     cat_test_cleanup();
0225     if (bm_pid)
0226         umount_resctrlfs();
0227
0228     return 0;
0229 }