1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Memory Bandwidth Allocation (MBA) 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
 13#define RESULT_FILE_NAME	"result_mba"
 14#define NUM_OF_RUNS		5
 15#define MAX_DIFF_PERCENT	8
 16#define ALLOCATION_MAX		100
 17#define ALLOCATION_MIN		10
 18#define ALLOCATION_STEP		10
 19
 20/*
 21 * Change schemata percentage from 100 to 10%. Write schemata to specified
 22 * con_mon grp, mon_grp in resctrl FS.
 23 * For each allocation, run 5 times in order to get average values.
 24 */
 25static int mba_setup(struct resctrl_val_param *p)
 26{
 27	static int runs_per_allocation, allocation = 100;
 28	char allocation_str[64];
 29	int ret;
 30
 31	if (runs_per_allocation >= NUM_OF_RUNS)
 32		runs_per_allocation = 0;
 33
 34	/* Only set up schemata once every NUM_OF_RUNS of allocations */
 35	if (runs_per_allocation++ != 0)
 36		return 0;
 37
 38	if (allocation < ALLOCATION_MIN || allocation > ALLOCATION_MAX)
 39		return END_OF_TESTS;
 40
 41	sprintf(allocation_str, "%d", allocation);
 42
 43	ret = write_schemata(p->ctrlgrp, allocation_str, p->cpu_no,
 44			     p->resctrl_val);
 45	if (ret < 0)
 46		return ret;
 47
 48	allocation -= ALLOCATION_STEP;
 49
 50	return 0;
 51}
 52
 53static bool show_mba_info(unsigned long *bw_imc, unsigned long *bw_resc)
 54{
 55	int allocation, runs;
 56	bool ret = false;
 57
 58	ksft_print_msg("Results are displayed in (MB)\n");
 59	/* Memory bandwidth from 100% down to 10% */
 60	for (allocation = 0; allocation < ALLOCATION_MAX / ALLOCATION_STEP;
 61	     allocation++) {
 62		unsigned long avg_bw_imc, avg_bw_resc;
 63		unsigned long sum_bw_imc = 0, sum_bw_resc = 0;
 64		int avg_diff_per;
 65		float avg_diff;
 66
 67		/*
 68		 * The first run is discarded due to inaccurate value from
 69		 * phase transition.
 70		 */
 71		for (runs = NUM_OF_RUNS * allocation + 1;
 72		     runs < NUM_OF_RUNS * allocation + NUM_OF_RUNS ; runs++) {
 73			sum_bw_imc += bw_imc[runs];
 74			sum_bw_resc += bw_resc[runs];
 75		}
 76
 77		avg_bw_imc = sum_bw_imc / (NUM_OF_RUNS - 1);
 78		avg_bw_resc = sum_bw_resc / (NUM_OF_RUNS - 1);
 79		avg_diff = (float)labs(avg_bw_resc - avg_bw_imc) / avg_bw_imc;
 80		avg_diff_per = (int)(avg_diff * 100);
 81
 82		ksft_print_msg("%s Check MBA diff within %d%% for schemata %u\n",
 83			       avg_diff_per > MAX_DIFF_PERCENT ?
 84			       "Fail:" : "Pass:",
 85			       MAX_DIFF_PERCENT,
 86			       ALLOCATION_MAX - ALLOCATION_STEP * allocation);
 87
 88		ksft_print_msg("avg_diff_per: %d%%\n", avg_diff_per);
 89		ksft_print_msg("avg_bw_imc: %lu\n", avg_bw_imc);
 90		ksft_print_msg("avg_bw_resc: %lu\n", avg_bw_resc);
 91		if (avg_diff_per > MAX_DIFF_PERCENT)
 92			ret = true;
 93	}
 94
 95	ksft_print_msg("%s Check schemata change using MBA\n",
 96		       ret ? "Fail:" : "Pass:");
 97	if (ret)
 98		ksft_print_msg("At least one test failed\n");
 99
100	return ret;
101}
102
103static int check_results(void)
104{
105	char *token_array[8], output[] = RESULT_FILE_NAME, temp[512];
106	unsigned long bw_imc[1024], bw_resc[1024];
107	int runs;
108	FILE *fp;
109
110	fp = fopen(output, "r");
111	if (!fp) {
112		perror(output);
113
114		return errno;
115	}
116
117	runs = 0;
118	while (fgets(temp, sizeof(temp), fp)) {
119		char *token = strtok(temp, ":\t");
120		int fields = 0;
121
122		while (token) {
123			token_array[fields++] = token;
124			token = strtok(NULL, ":\t");
125		}
126
127		/* Field 3 is perf imc value */
128		bw_imc[runs] = strtoul(token_array[3], NULL, 0);
129		/* Field 5 is resctrl value */
130		bw_resc[runs] = strtoul(token_array[5], NULL, 0);
131		runs++;
132	}
133
134	fclose(fp);
135
136	return show_mba_info(bw_imc, bw_resc);
137}
138
139void mba_test_cleanup(void)
140{
141	remove(RESULT_FILE_NAME);
142}
143
144int mba_schemata_change(int cpu_no, const char * const *benchmark_cmd)
145{
146	struct resctrl_val_param param = {
147		.resctrl_val	= MBA_STR,
148		.ctrlgrp	= "c1",
149		.mongrp		= "m1",
150		.cpu_no		= cpu_no,
151		.filename	= RESULT_FILE_NAME,
152		.bw_report	= "reads",
153		.setup		= mba_setup
154	};
155	int ret;
156
157	remove(RESULT_FILE_NAME);
158
159	ret = resctrl_val(benchmark_cmd, &param);
160	if (ret)
161		goto out;
162
163	ret = check_results();
164
165out:
166	mba_test_cleanup();
167
168	return ret;
169}