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	5
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  */
25 static 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 
32 	va_start(param, num);
33 	p = va_arg(param, struct resctrl_val_param *);
34 	va_end(param);
35 
36 	if (runs_per_allocation >= NUM_OF_RUNS)
37 		runs_per_allocation = 0;
38 
39 	/* Only set up schemata once every NUM_OF_RUNS of allocations */
40 	if (runs_per_allocation++ != 0)
41 		return 0;
42 
43 	if (allocation < ALLOCATION_MIN || allocation > ALLOCATION_MAX)
44 		return -1;
45 
46 	sprintf(allocation_str, "%d", allocation);
47 
48 	write_schemata(p->ctrlgrp, allocation_str, p->cpu_no, p->resctrl_val);
49 	allocation -= ALLOCATION_STEP;
50 
51 	return 0;
52 }
53 
54 static void show_mba_info(unsigned long *bw_imc, unsigned long *bw_resc)
55 {
56 	int allocation, runs;
57 	bool failed = 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 			failed = true;
94 	}
95 
96 	ksft_print_msg("%s Check schemata change using MBA\n",
97 		       failed ? "Fail:" : "Pass:");
98 	if (failed)
99 		ksft_print_msg("At least one test failed\n");
100 }
101 
102 static int check_results(void)
103 {
104 	char *token_array[8], output[] = RESULT_FILE_NAME, temp[512];
105 	unsigned long bw_imc[1024], bw_resc[1024];
106 	int runs;
107 	FILE *fp;
108 
109 	fp = fopen(output, "r");
110 	if (!fp) {
111 		perror(output);
112 
113 		return errno;
114 	}
115 
116 	runs = 0;
117 	while (fgets(temp, sizeof(temp), fp)) {
118 		char *token = strtok(temp, ":\t");
119 		int fields = 0;
120 
121 		while (token) {
122 			token_array[fields++] = token;
123 			token = strtok(NULL, ":\t");
124 		}
125 
126 		/* Field 3 is perf imc value */
127 		bw_imc[runs] = strtoul(token_array[3], NULL, 0);
128 		/* Field 5 is resctrl value */
129 		bw_resc[runs] = strtoul(token_array[5], NULL, 0);
130 		runs++;
131 	}
132 
133 	fclose(fp);
134 
135 	show_mba_info(bw_imc, bw_resc);
136 
137 	return 0;
138 }
139 
140 void mba_test_cleanup(void)
141 {
142 	remove(RESULT_FILE_NAME);
143 }
144 
145 int mba_schemata_change(int cpu_no, char *bw_report, char **benchmark_cmd)
146 {
147 	struct resctrl_val_param param = {
148 		.resctrl_val	= MBA_STR,
149 		.ctrlgrp	= "c1",
150 		.mongrp		= "m1",
151 		.cpu_no		= cpu_no,
152 		.mum_resctrlfs	= 1,
153 		.filename	= RESULT_FILE_NAME,
154 		.bw_report	= bw_report,
155 		.setup		= mba_setup
156 	};
157 	int ret;
158 
159 	remove(RESULT_FILE_NAME);
160 
161 	ret = resctrl_val(benchmark_cmd, &param);
162 	if (ret)
163 		return ret;
164 
165 	ret = check_results();
166 	if (ret)
167 		return ret;
168 
169 	mba_test_cleanup();
170 
171 	return 0;
172 }
173