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(const struct resctrl_test *test,
 26		     const struct user_params *uparams,
 27		     struct resctrl_val_param *p)
 28{
 29	static int runs_per_allocation, allocation = 100;
 30	char allocation_str[64];
 31	int ret;
 32
 33	if (runs_per_allocation >= NUM_OF_RUNS)
 34		runs_per_allocation = 0;
 35
 36	/* Only set up schemata once every NUM_OF_RUNS of allocations */
 37	if (runs_per_allocation++ != 0)
 38		return 0;
 39
 40	if (allocation < ALLOCATION_MIN || allocation > ALLOCATION_MAX)
 41		return END_OF_TESTS;
 42
 43	sprintf(allocation_str, "%d", allocation);
 44
 45	ret = write_schemata(p->ctrlgrp, allocation_str, uparams->cpu, test->resource);
 46	if (ret < 0)
 47		return ret;
 48
 49	allocation -= ALLOCATION_STEP;
 50
 51	return 0;
 52}
 53
 54static bool show_mba_info(unsigned long *bw_imc, unsigned long *bw_resc)
 55{
 56	int allocation, runs;
 57	bool ret = false;
 58
 59	ksft_print_msg("Results are displayed in (MB)\n");
 60	/* Memory bandwidth from 100% down to 10% */
 61	for (allocation = 0; allocation < ALLOCATION_MAX / ALLOCATION_STEP;
 62	     allocation++) {
 63		unsigned long avg_bw_imc, avg_bw_resc;
 64		unsigned long sum_bw_imc = 0, sum_bw_resc = 0;
 65		int avg_diff_per;
 66		float avg_diff;
 67
 68		/*
 69		 * The first run is discarded due to inaccurate value from
 70		 * phase transition.
 71		 */
 72		for (runs = NUM_OF_RUNS * allocation + 1;
 73		     runs < NUM_OF_RUNS * allocation + NUM_OF_RUNS ; runs++) {
 74			sum_bw_imc += bw_imc[runs];
 75			sum_bw_resc += bw_resc[runs];
 76		}
 77
 78		avg_bw_imc = sum_bw_imc / (NUM_OF_RUNS - 1);
 79		avg_bw_resc = sum_bw_resc / (NUM_OF_RUNS - 1);
 80		avg_diff = (float)labs(avg_bw_resc - avg_bw_imc) / avg_bw_imc;
 81		avg_diff_per = (int)(avg_diff * 100);
 82
 83		ksft_print_msg("%s Check MBA diff within %d%% for schemata %u\n",
 84			       avg_diff_per > MAX_DIFF_PERCENT ?
 85			       "Fail:" : "Pass:",
 86			       MAX_DIFF_PERCENT,
 87			       ALLOCATION_MAX - ALLOCATION_STEP * allocation);
 88
 89		ksft_print_msg("avg_diff_per: %d%%\n", avg_diff_per);
 90		ksft_print_msg("avg_bw_imc: %lu\n", avg_bw_imc);
 91		ksft_print_msg("avg_bw_resc: %lu\n", avg_bw_resc);
 92		if (avg_diff_per > MAX_DIFF_PERCENT)
 93			ret = true;
 94	}
 95
 96	ksft_print_msg("%s Check schemata change using MBA\n",
 97		       ret ? "Fail:" : "Pass:");
 98	if (ret)
 99		ksft_print_msg("At least one test failed\n");
100
101	return ret;
102}
103
104static int check_results(void)
105{
106	char *token_array[8], output[] = RESULT_FILE_NAME, temp[512];
107	unsigned long bw_imc[1024], bw_resc[1024];
108	int runs;
109	FILE *fp;
110
111	fp = fopen(output, "r");
112	if (!fp) {
113		ksft_perror(output);
114
115		return -1;
116	}
117
118	runs = 0;
119	while (fgets(temp, sizeof(temp), fp)) {
120		char *token = strtok(temp, ":\t");
121		int fields = 0;
122
123		while (token) {
124			token_array[fields++] = token;
125			token = strtok(NULL, ":\t");
126		}
127
128		/* Field 3 is perf imc value */
129		bw_imc[runs] = strtoul(token_array[3], NULL, 0);
130		/* Field 5 is resctrl value */
131		bw_resc[runs] = strtoul(token_array[5], NULL, 0);
132		runs++;
133	}
134
135	fclose(fp);
136
137	return show_mba_info(bw_imc, bw_resc);
138}
139
140void mba_test_cleanup(void)
141{
142	remove(RESULT_FILE_NAME);
143}
144
145static int mba_run_test(const struct resctrl_test *test, const struct user_params *uparams)
146{
147	struct resctrl_val_param param = {
148		.resctrl_val	= MBA_STR,
149		.ctrlgrp	= "c1",
150		.mongrp		= "m1",
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(test, uparams, uparams->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}
170
171static bool mba_feature_check(const struct resctrl_test *test)
172{
173	return test_resource_feature_check(test) &&
174	       resctrl_mon_feature_exists("L3_MON", "mbm_local_bytes");
175}
176
177struct resctrl_test mba_test = {
178	.name = "MBA",
179	.resource = "MB",
180	.vendor_specific = ARCH_INTEL,
181	.feature_check = mba_feature_check,
182	.run_test = mba_run_test,
183};