1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Memory Bandwidth Monitoring (MBM) 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_mbm"
 14#define MAX_DIFF_PERCENT	8
 15#define NUM_OF_RUNS		5
 16
 17static int
 18show_bw_info(unsigned long *bw_imc, unsigned long *bw_resc, size_t span)
 19{
 20	unsigned long sum_bw_imc = 0, sum_bw_resc = 0;
 21	long avg_bw_imc = 0, avg_bw_resc = 0;
 22	int runs, ret, avg_diff_per;
 23	float avg_diff = 0;
 24
 25	for (runs = 0; runs < NUM_OF_RUNS; runs++) {
 26		sum_bw_imc += bw_imc[runs];
 27		sum_bw_resc += bw_resc[runs];
 28	}
 29
 30	avg_bw_imc = sum_bw_imc / NUM_OF_RUNS;
 31	avg_bw_resc = sum_bw_resc / NUM_OF_RUNS;
 32	avg_diff = (float)labs(avg_bw_resc - avg_bw_imc) / avg_bw_imc;
 33	avg_diff_per = (int)(avg_diff * 100);
 34
 35	ret = avg_diff_per > MAX_DIFF_PERCENT;
 36	ksft_print_msg("%s Check MBM diff within %d%%\n",
 37		       ret ? "Fail:" : "Pass:", MAX_DIFF_PERCENT);
 38	ksft_print_msg("avg_diff_per: %d%%\n", avg_diff_per);
 39	if (span)
 40		ksft_print_msg("Span (MB): %zu\n", span / MB);
 41	ksft_print_msg("avg_bw_imc: %lu\n", avg_bw_imc);
 42	ksft_print_msg("avg_bw_resc: %lu\n", avg_bw_resc);
 43
 44	return ret;
 45}
 46
 47static int check_results(size_t span)
 48{
 49	unsigned long bw_imc[NUM_OF_RUNS], bw_resc[NUM_OF_RUNS];
 50	char temp[1024], *token_array[8];
 51	char output[] = RESULT_FILE_NAME;
 52	int runs, ret;
 53	FILE *fp;
 54
 55	ksft_print_msg("Checking for pass/fail\n");
 56
 57	fp = fopen(output, "r");
 58	if (!fp) {
 59		ksft_perror(output);
 60
 61		return -1;
 62	}
 63
 64	runs = 0;
 65	while (fgets(temp, sizeof(temp), fp)) {
 66		char *token = strtok(temp, ":\t");
 67		int i = 0;
 68
 69		while (token) {
 70			token_array[i++] = token;
 71			token = strtok(NULL, ":\t");
 72		}
 73
 74		bw_resc[runs] = strtoul(token_array[5], NULL, 0);
 75		bw_imc[runs] = strtoul(token_array[3], NULL, 0);
 76		runs++;
 77	}
 78
 79	ret = show_bw_info(bw_imc, bw_resc, span);
 80
 81	fclose(fp);
 82
 83	return ret;
 84}
 85
 86static int mbm_init(const struct resctrl_val_param *param, int domain_id)
 87{
 88	int ret;
 89
 90	ret = initialize_read_mem_bw_imc();
 91	if (ret)
 92		return ret;
 93
 94	initialize_mem_bw_resctrl(param, domain_id);
 95
 96	return 0;
 97}
 98
 99static int mbm_setup(const struct resctrl_test *test,
100		     const struct user_params *uparams,
101		     struct resctrl_val_param *p)
102{
103	int ret = 0;
104
105	/* Run NUM_OF_RUNS times */
106	if (p->num_of_runs >= NUM_OF_RUNS)
107		return END_OF_TESTS;
108
109	/* Set up shemata with 100% allocation on the first run. */
110	if (p->num_of_runs == 0 && resctrl_resource_exists("MB"))
111		ret = write_schemata(p->ctrlgrp, "100", uparams->cpu, test->resource);
112
113	p->num_of_runs++;
114
115	return ret;
116}
117
118static int mbm_measure(const struct user_params *uparams,
119		       struct resctrl_val_param *param, pid_t bm_pid)
120{
121	return measure_read_mem_bw(uparams, param, bm_pid);
122}
123
124static void mbm_test_cleanup(void)
125{
126	remove(RESULT_FILE_NAME);
127}
128
129static int mbm_run_test(const struct resctrl_test *test, const struct user_params *uparams)
130{
131	struct resctrl_val_param param = {
132		.ctrlgrp	= "c1",
133		.filename	= RESULT_FILE_NAME,
134		.init		= mbm_init,
135		.setup		= mbm_setup,
136		.measure	= mbm_measure,
137	};
138	struct fill_buf_param fill_buf = {};
139	int ret;
140
141	remove(RESULT_FILE_NAME);
142
143	if (uparams->fill_buf) {
144		fill_buf.buf_size = uparams->fill_buf->buf_size;
145		fill_buf.memflush = uparams->fill_buf->memflush;
146		param.fill_buf = &fill_buf;
147	} else if (!uparams->benchmark_cmd[0]) {
148		ssize_t buf_size;
149
150		buf_size = get_fill_buf_size(uparams->cpu, "L3");
151		if (buf_size < 0)
152			return buf_size;
153		fill_buf.buf_size = buf_size;
154		fill_buf.memflush = true;
155		param.fill_buf = &fill_buf;
156	}
157
158	ret = resctrl_val(test, uparams, &param);
159	if (ret)
160		return ret;
161
162	ret = check_results(param.fill_buf ? param.fill_buf->buf_size : 0);
163	if (ret && (get_vendor() == ARCH_INTEL))
164		ksft_print_msg("Intel MBM may be inaccurate when Sub-NUMA Clustering is enabled. Check BIOS configuration.\n");
165
166	return ret;
167}
168
169static bool mbm_feature_check(const struct resctrl_test *test)
170{
171	return resctrl_mon_feature_exists("L3_MON", "mbm_total_bytes") &&
172	       resctrl_mon_feature_exists("L3_MON", "mbm_local_bytes");
173}
174
175struct resctrl_test mbm_test = {
176	.name = "MBM",
177	.resource = "MB",
178	.vendor_specific = ARCH_INTEL,
179	.feature_check = mbm_feature_check,
180	.run_test = mbm_run_test,
181	.cleanup = mbm_test_cleanup,
182};