selftests/resctrl/mbm_test.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Memory Bandwidth Monitoring (MBM) 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
0013 #define RESULT_FILE_NAME    "result_mbm"
0014 #define MAX_DIFF_PERCENT    5
0015 #define NUM_OF_RUNS     5
0016
0017 static int
0018 show_bw_info(unsigned long *bw_imc, unsigned long *bw_resc, int span)
0019 {
0020     unsigned long avg_bw_imc = 0, avg_bw_resc = 0;
0021     unsigned long sum_bw_imc = 0, sum_bw_resc = 0;
0022     int runs, ret, avg_diff_per;
0023     float avg_diff = 0;
0024
0025     /*
0026      * Discard the first value which is inaccurate due to monitoring setup
0027      * transition phase.
0028      */
0029     for (runs = 1; runs < NUM_OF_RUNS ; runs++) {
0030         sum_bw_imc += bw_imc[runs];
0031         sum_bw_resc += bw_resc[runs];
0032     }
0033
0034     avg_bw_imc = sum_bw_imc / 4;
0035     avg_bw_resc = sum_bw_resc / 4;
0036     avg_diff = (float)labs(avg_bw_resc - avg_bw_imc) / avg_bw_imc;
0037     avg_diff_per = (int)(avg_diff * 100);
0038
0039     ret = avg_diff_per > MAX_DIFF_PERCENT;
0040     ksft_print_msg("%s Check MBM diff within %d%%\n",
0041                ret ? "Fail:" : "Pass:", MAX_DIFF_PERCENT);
0042     ksft_print_msg("avg_diff_per: %d%%\n", avg_diff_per);
0043     ksft_print_msg("Span (MB): %d\n", span);
0044     ksft_print_msg("avg_bw_imc: %lu\n", avg_bw_imc);
0045     ksft_print_msg("avg_bw_resc: %lu\n", avg_bw_resc);
0046
0047     return ret;
0048 }
0049
0050 static int check_results(int span)
0051 {
0052     unsigned long bw_imc[NUM_OF_RUNS], bw_resc[NUM_OF_RUNS];
0053     char temp[1024], *token_array[8];
0054     char output[] = RESULT_FILE_NAME;
0055     int runs, ret;
0056     FILE *fp;
0057
0058     ksft_print_msg("Checking for pass/fail\n");
0059
0060     fp = fopen(output, "r");
0061     if (!fp) {
0062         perror(output);
0063
0064         return errno;
0065     }
0066
0067     runs = 0;
0068     while (fgets(temp, sizeof(temp), fp)) {
0069         char *token = strtok(temp, ":\t");
0070         int i = 0;
0071
0072         while (token) {
0073             token_array[i++] = token;
0074             token = strtok(NULL, ":\t");
0075         }
0076
0077         bw_resc[runs] = strtoul(token_array[5], NULL, 0);
0078         bw_imc[runs] = strtoul(token_array[3], NULL, 0);
0079         runs++;
0080     }
0081
0082     ret = show_bw_info(bw_imc, bw_resc, span);
0083
0084     fclose(fp);
0085
0086     return ret;
0087 }
0088
0089 static int mbm_setup(int num, ...)
0090 {
0091     struct resctrl_val_param *p;
0092     static int num_of_runs;
0093     va_list param;
0094     int ret = 0;
0095
0096     /* Run NUM_OF_RUNS times */
0097     if (num_of_runs++ >= NUM_OF_RUNS)
0098         return -1;
0099
0100     va_start(param, num);
0101     p = va_arg(param, struct resctrl_val_param *);
0102     va_end(param);
0103
0104     /* Set up shemata with 100% allocation on the first run. */
0105     if (num_of_runs == 0)
0106         ret = write_schemata(p->ctrlgrp, "100", p->cpu_no,
0107                      p->resctrl_val);
0108
0109     return ret;
0110 }
0111
0112 void mbm_test_cleanup(void)
0113 {
0114     remove(RESULT_FILE_NAME);
0115 }
0116
0117 int mbm_bw_change(int span, int cpu_no, char *bw_report, char **benchmark_cmd)
0118 {
0119     struct resctrl_val_param param = {
0120         .resctrl_val    = MBM_STR,
0121         .ctrlgrp    = "c1",
0122         .mongrp     = "m1",
0123         .span       = span,
0124         .cpu_no     = cpu_no,
0125         .mum_resctrlfs  = 1,
0126         .filename   = RESULT_FILE_NAME,
0127         .bw_report  =  bw_report,
0128         .setup      = mbm_setup
0129     };
0130     int ret;
0131
0132     remove(RESULT_FILE_NAME);
0133
0134     ret = resctrl_val(benchmark_cmd, &param);
0135     if (ret)
0136         return ret;
0137
0138     ret = check_results(span);
0139     if (ret)
0140         return ret;
0141
0142     mbm_test_cleanup();
0143
0144     return 0;
0145 }