summaryrefslogtreecommitdiff
path: root/tools/testing/selftests/resctrl/fill_buf.c
blob: 0d425f26583a9596479ae8a017c70d3523fa25a8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
// SPDX-License-Identifier: GPL-2.0
/*
 * fill_buf benchmark
 *
 * Copyright (C) 2018 Intel Corporation
 *
 * Authors:
 *    Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
 *    Fenghua Yu <fenghua.yu@intel.com>
 */
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <inttypes.h>
#include <string.h>

#include "resctrl.h"

#define CL_SIZE			(64)
#define PAGE_SIZE		(4 * 1024)
#define MB			(1024 * 1024)

static void sb(void)
{
#if defined(__i386) || defined(__x86_64)
	asm volatile("sfence\n\t"
		     : : : "memory");
#endif
}

static void cl_flush(void *p)
{
#if defined(__i386) || defined(__x86_64)
	asm volatile("clflush (%0)\n\t"
		     : : "r"(p) : "memory");
#endif
}

static void mem_flush(unsigned char *buf, size_t buf_size)
{
	unsigned char *cp = buf;
	size_t i = 0;

	buf_size = buf_size / CL_SIZE; /* mem size in cache lines */

	for (i = 0; i < buf_size; i++)
		cl_flush(&cp[i * CL_SIZE]);

	sb();
}

static void *malloc_and_init_memory(size_t buf_size)
{
	void *p = NULL;
	uint64_t *p64;
	size_t s64;
	int ret;

	ret = posix_memalign(&p, PAGE_SIZE, buf_size);
	if (ret < 0)
		return NULL;

	p64 = (uint64_t *)p;
	s64 = buf_size / sizeof(uint64_t);

	while (s64 > 0) {
		*p64 = (uint64_t)rand();
		p64 += (CL_SIZE / sizeof(uint64_t));
		s64 -= (CL_SIZE / sizeof(uint64_t));
	}

	return p;
}

static int fill_one_span_read(unsigned char *buf, size_t buf_size)
{
	unsigned char *end_ptr = buf + buf_size;
	unsigned char sum, *p;

	sum = 0;
	p = buf;
	while (p < end_ptr) {
		sum += *p;
		p += (CL_SIZE / 2);
	}

	return sum;
}

static void fill_one_span_write(unsigned char *buf, size_t buf_size)
{
	unsigned char *end_ptr = buf + buf_size;
	unsigned char *p;

	p = buf;
	while (p < end_ptr) {
		*p = '1';
		p += (CL_SIZE / 2);
	}
}

static int fill_cache_read(unsigned char *buf, size_t buf_size, bool once)
{
	int ret = 0;
	FILE *fp;

	while (1) {
		ret = fill_one_span_read(buf, buf_size);
		if (once)
			break;
	}

	/* Consume read result so that reading memory is not optimized out. */
	fp = fopen("/dev/null", "w");
	if (!fp) {
		perror("Unable to write to /dev/null");
		return -1;
	}
	fprintf(fp, "Sum: %d ", ret);
	fclose(fp);

	return 0;
}

static int fill_cache_write(unsigned char *buf, size_t buf_size, bool once)
{
	while (1) {
		fill_one_span_write(buf, buf_size);
		if (once)
			break;
	}

	return 0;
}

static int fill_cache(size_t buf_size, int memflush, int op, bool once)
{
	unsigned char *buf;
	int ret;

	buf = malloc_and_init_memory(buf_size);
	if (!buf)
		return -1;

	/* Flush the memory before using to avoid "cache hot pages" effect */
	if (memflush)
		mem_flush(buf, buf_size);

	if (op == 0)
		ret = fill_cache_read(buf, buf_size, once);
	else
		ret = fill_cache_write(buf, buf_size, once);

	free(buf);

	if (ret) {
		printf("\n Error in fill cache read/write...\n");
		return -1;
	}


	return 0;
}

int run_fill_buf(size_t span, int memflush, int op, bool once)
{
	size_t cache_size = span;
	int ret;

	ret = fill_cache(cache_size, memflush, op, once);
	if (ret) {
		printf("\n Error in fill cache\n");
		return -1;
	}

	return 0;
}