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		300
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(int num, ...)
26{
27	static int runs_per_allocation, allocation = 100;
28	struct resctrl_val_param *p;
29	char allocation_str[64];
30	va_list param;
31	int ret;
32
33	va_start(param, num);
34	p = va_arg(param, struct resctrl_val_param *);
35	va_end(param);
36
37	if (runs_per_allocation >= NUM_OF_RUNS)
38		runs_per_allocation = 0;
39
40	/* Only set up schemata once every NUM_OF_RUNS of allocations */
41	if (runs_per_allocation++ != 0)
42		return 0;
43
44	if (allocation < ALLOCATION_MIN || allocation > ALLOCATION_MAX)
45		return -1;
46
47	sprintf(allocation_str, "%d", allocation);
48
49	ret = write_schemata(p->ctrlgrp, allocation_str, p->cpu_no,
50			     p->resctrl_val);
51	if (ret < 0)
52		return ret;
53
54	allocation -= ALLOCATION_STEP;
55
56	return 0;
57}
58
59static void show_mba_info(unsigned long *bw_imc, unsigned long *bw_resc)
60{
61	int allocation, runs;
62	bool failed = false;
63
64	printf("# Results are displayed in (MB)\n");
65	/* Memory bandwidth from 100% down to 10% */
66	for (allocation = 0; allocation < ALLOCATION_MAX / ALLOCATION_STEP;
67	     allocation++) {
68		unsigned long avg_bw_imc, avg_bw_resc;
69		unsigned long sum_bw_imc = 0, sum_bw_resc = 0;
70		unsigned long avg_diff;
71
72		/*
73		 * The first run is discarded due to inaccurate value from
74		 * phase transition.
75		 */
76		for (runs = NUM_OF_RUNS * allocation + 1;
77		     runs < NUM_OF_RUNS * allocation + NUM_OF_RUNS ; runs++) {
78			sum_bw_imc += bw_imc[runs];
79			sum_bw_resc += bw_resc[runs];
80		}
81
82		avg_bw_imc = sum_bw_imc / (NUM_OF_RUNS - 1);
83		avg_bw_resc = sum_bw_resc / (NUM_OF_RUNS - 1);
84		avg_diff = labs((long)(avg_bw_resc - avg_bw_imc));
85
86		printf("%sok MBA schemata percentage %u smaller than %d %%\n",
87		       avg_diff > MAX_DIFF ? "not " : "",
88		       ALLOCATION_MAX - ALLOCATION_STEP * allocation,
89		       MAX_DIFF);
90		tests_run++;
91		printf("# avg_diff: %lu\n", avg_diff);
92		printf("# avg_bw_imc: %lu\n", avg_bw_imc);
93		printf("# avg_bw_resc: %lu\n", avg_bw_resc);
94		if (avg_diff > MAX_DIFF)
95			failed = true;
96	}
97
98	printf("%sok schemata change using MBA%s\n", failed ? "not " : "",
99	       failed ? " # at least one test failed" : "");
100	tests_run++;
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	show_mba_info(bw_imc, bw_resc);
137
138	return 0;
139}
140
141void mba_test_cleanup(void)
142{
143	remove(RESULT_FILE_NAME);
144}
145
146int mba_schemata_change(int cpu_no, char *bw_report, char **benchmark_cmd)
147{
148	struct resctrl_val_param param = {
149		.resctrl_val	= MBA_STR,
150		.ctrlgrp	= "c1",
151		.mongrp		= "m1",
152		.cpu_no		= cpu_no,
153		.mum_resctrlfs	= 1,
154		.filename	= RESULT_FILE_NAME,
155		.bw_report	= bw_report,
156		.setup		= mba_setup
157	};
158	int ret;
159
160	remove(RESULT_FILE_NAME);
161
162	if (!validate_resctrl_feature_request("mba"))
163		return -1;
164
165	ret = resctrl_val(benchmark_cmd, &param);
166	if (ret)
167		return ret;
168
169	ret = check_results();
170	if (ret)
171		return ret;
172
173	mba_test_cleanup();
174
175	return 0;
176}
177