1 /*
2 * Copyright (c) 2016, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24 #include "precompiled.hpp"
25 #include "runtime/os.hpp"
26 #include "unittest.hpp"
27
28 static size_t small_page_size() {
29 return os::vm_page_size();
30 }
31
32 static size_t large_page_size() {
33 const size_t large_page_size_example = 4 * M;
34 return os::page_size_for_region_aligned(large_page_size_example, 1);
35 }
36
37 TEST_VM(os, page_size_for_region) {
38 size_t large_page_example = 4 * M;
39 size_t large_page = os::page_size_for_region_aligned(large_page_example, 1);
40
41 size_t small_page = os::vm_page_size();
42 if (large_page > small_page) {
43 size_t num_small_in_large = large_page / small_page;
44 size_t page = os::page_size_for_region_aligned(large_page, num_small_in_large);
45 ASSERT_EQ(page, small_page) << "Did not get a small page";
46 }
47 }
48
49 TEST_VM(os, page_size_for_region_aligned) {
50 if (UseLargePages) {
51 const size_t small_page = small_page_size();
52 const size_t large_page = large_page_size();
53
54 if (large_page > small_page) {
55 size_t num_small_pages_in_large = large_page / small_page;
56 size_t page = os::page_size_for_region_aligned(large_page, num_small_pages_in_large);
57
58 ASSERT_EQ(page, small_page);
59 }
60 }
61 }
62
63 TEST_VM(os, page_size_for_region_alignment) {
64 if (UseLargePages) {
65 const size_t small_page = small_page_size();
66 const size_t large_page = large_page_size();
67 if (large_page > small_page) {
68 const size_t unaligned_region = large_page + 17;
69 size_t page = os::page_size_for_region_aligned(unaligned_region, 1);
70 ASSERT_EQ(page, small_page);
71
72 const size_t num_pages = 5;
73 const size_t aligned_region = large_page * num_pages;
74 page = os::page_size_for_region_aligned(aligned_region, num_pages);
75 ASSERT_EQ(page, large_page);
76 }
77 }
78 }
79
80 TEST_VM(os, page_size_for_region_unaligned) {
81 if (UseLargePages) {
82 // Given exact page size, should return that page size.
83 for (size_t i = 0; os::_page_sizes[i] != 0; i++) {
84 size_t expected = os::_page_sizes[i];
85 size_t actual = os::page_size_for_region_unaligned(expected, 1);
86 ASSERT_EQ(expected, actual);
87 }
88
89 // Given slightly larger size than a page size, return the page size.
90 for (size_t i = 0; os::_page_sizes[i] != 0; i++) {
91 size_t expected = os::_page_sizes[i];
92 size_t actual = os::page_size_for_region_unaligned(expected + 17, 1);
93 ASSERT_EQ(expected, actual);
94 }
95
96 // Given a slightly smaller size than a page size,
97 // return the next smaller page size.
98 if (os::_page_sizes[1] > os::_page_sizes[0]) {
99 size_t expected = os::_page_sizes[0];
100 size_t actual = os::page_size_for_region_unaligned(os::_page_sizes[1] - 17, 1);
101 ASSERT_EQ(actual, expected);
102 }
103
104 // Return small page size for values less than a small page.
105 size_t small_page = small_page_size();
106 size_t actual = os::page_size_for_region_unaligned(small_page - 17, 1);
107 ASSERT_EQ(small_page, actual);
108 }
109 }
110
111 TEST(os, test_random) {
112 const double m = 2147483647;
113 double mean = 0.0, variance = 0.0, t;
114 const int reps = 10000;
115 unsigned int seed = 1;
116
117 // tty->print_cr("seed %ld for %ld repeats...", seed, reps);
118 os::init_random(seed);
119 int num;
120 for (int k = 0; k < reps; k++) {
121 num = os::random();
122 double u = (double)num / m;
123 ASSERT_TRUE(u >= 0.0 && u <= 1.0) << "bad random number!";
124
125 // calculate mean and variance of the random sequence
126 mean += u;
127 variance += (u*u);
128 }
129 mean /= reps;
130 variance /= (reps - 1);
131
132 ASSERT_EQ(num, 1043618065) << "bad seed";
133 // tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
134 int intmean = mean*100;
135 ASSERT_EQ(intmean, 50);
136 // tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
137 int intvariance = variance*100;
138 ASSERT_EQ(intvariance, 33);
139 const double eps = 0.0001;
140 t = fabsd(mean - 0.5018);
141 ASSERT_LT(t, eps) << "bad mean";
142 t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
143 ASSERT_LT(t, eps) << "bad variance";
144 }
145
146
147 #ifdef ASSERT
148 TEST_VM_ASSERT_MSG(os, page_size_for_region_with_zero_min_pages, "sanity") {
149 size_t region_size = 16 * os::vm_page_size();
150 os::page_size_for_region_aligned(region_size, 0); // should assert
151 }
152 #endif