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Serenity Operating System
1/*
2 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice, this
9 * list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
22 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <AK/String.h>
28#include <LibCore/ElapsedTimer.h>
29#include <stdio.h>
30#include <string.h>
31#include <unistd.h>
32
33void usage(void)
34{
35 printf("usage: allocate [number [unit (B/KB/MB)]]\n");
36 exit(1);
37}
38
39enum Unit { Bytes, KiloBytes, MegaBytes };
40
41int main(int argc, char** argv)
42{
43 int count = 50;
44 Unit unit = MegaBytes;
45
46 if (argc >= 2) {
47 bool ok;
48 count = String(argv[1]).to_uint(ok);
49 if (!ok) {
50 usage();
51 }
52 }
53
54 if (argc >= 3) {
55 if (strcmp(argv[2], "B") == 0)
56 unit = Bytes;
57 else if (strcmp(argv[2], "KB") == 0)
58 unit = KiloBytes;
59 else if (strcmp(argv[2], "MB") == 0)
60 unit = MegaBytes;
61 else
62 usage();
63 }
64
65 switch (unit) {
66 case Bytes:
67 break;
68 case KiloBytes:
69 count *= 1024;
70 break;
71 case MegaBytes:
72 count *= 1024 * 1024;
73 break;
74 }
75
76 Core::ElapsedTimer timer;
77
78 printf("allocating memory (%d bytes)...\n", count);
79 timer.start();
80 char* ptr = (char*)malloc(count);
81 if (!ptr) {
82 printf("failed.\n");
83 return 1;
84 }
85 printf("done in %dms\n", timer.elapsed());
86
87 auto pages = count / 4096;
88 auto step = pages / 10;
89
90 Core::ElapsedTimer timer2;
91
92 printf("writing one byte to each page of allocated memory...\n");
93 timer.start();
94 timer2.start();
95 for (int i = 0; i < pages; ++i) {
96 ptr[i * 4096] = 1;
97
98 if (i != 0 && (i % step) == 0) {
99 auto ms = timer2.elapsed();
100 if (ms == 0)
101 ms = 1;
102
103 auto bps = double(step * 4096) / (double(ms) / 1000);
104
105 printf("step took %dms (%fMB/s)\n", ms, bps / 1024 / 1024);
106
107 timer2.start();
108 }
109 }
110 printf("done in %dms\n", timer.elapsed());
111
112 printf("sleeping for ten seconds...\n");
113 for (int i = 0; i < 10; i++) {
114 printf("%d\n", i);
115 sleep(1);
116 }
117 printf("done.\n");
118
119 printf("freeing memory...\n");
120 timer.start();
121 free(ptr);
122 printf("done in %dms\n", timer.elapsed());
123
124 return 0;
125}