1 /*
2 * Kernel Samepage Merging (KSM) for Memory Resource Controller
3 *
4 * Basic tests were to start several programs with same and different
5 * memory contents and ensure only to merge the ones with the same
6 * contents. When changed the content of one of merged pages in a
7 * process and to the mode "unmerging", it should discard all merged
8 * pages there. Also tested it is possible to disable KSM. There are
9 * also command-line options to specify the memory allocation size, and
10 * number of processes have same memory contents so it is possible to
11 * test more advanced things like KSM + OOM etc.
12 *
13 * Prerequisites:
14 *
15 * 1) ksm and ksmtuned daemons need to be disabled. Otherwise, it could
16 * distrub the testing as they also change some ksm tunables depends
17 * on current workloads.
18 *
19 * The test steps are:
20 * - Check ksm feature and backup current run setting.
21 * - Change run setting to 1 - merging.
22 * - 3 memory allocation programs have the memory contents that 2 of
23 * them are all 'a' and one is all 'b'.
24 * - Check ksm statistics and verify the content.
25 * - 1 program changes the memory content from all 'a' to all 'b'.
26 * - Check ksm statistics and verify the content.
27 * - All programs change the memory content to all 'd'.
28 * - Check ksm statistics and verify the content.
29 * - Change one page of a process.
30 * - Check ksm statistics and verify the content.
31 * - Change run setting to 2 - unmerging.
32 * - Check ksm statistics and verify the content.
33 * - Change run setting to 0 - stop.
34 *
35 * Copyright (C) 2010 Red Hat, Inc.
36 *
37 * This program is free software; you can redistribute it and/or
38 * modify it under the terms of version 2 of the GNU General Public
39 * License as published by the Free Software Foundation.
40 *
41 * This program is distributed in the hope that it would be useful,
42 * but WITHOUT ANY WARRANTY; without even the implied warranty of
43 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
44 *
45 * Further, this software is distributed without any warranty that it
46 * is free of the rightful claim of any third person regarding
47 * infringement or the like. Any license provided herein, whether
48 * implied or otherwise, applies only to this software file. Patent
49 * licenses, if any, provided herein do not apply to combinations of
50 * this program with other software, or any other product whatsoever.
51 *
52 * You should have received a copy of the GNU General Public License
53 * along with this program; if not, write the Free Software
54 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
55 * 02110-1301, USA.
56 */
57
58 #include <sys/types.h>
59 #include <sys/mman.h>
60 #include <sys/stat.h>
61 #include <sys/wait.h>
62 #include <errno.h>
63 #include <fcntl.h>
64 #include <signal.h>
65 #include <stdio.h>
66 #include <stdlib.h>
67 #include <string.h>
68 #include <unistd.h>
69 #include "test.h"
70 #include "mem.h"
71
72 char *TCID = "ksm03";
73 int TST_TOTAL = 1;
74
75 static int merge_across_nodes;
76
77 option_t ksm_options[] = {
78 {"n:", &opt_num, &opt_numstr},
79 {"s:", &opt_size, &opt_sizestr},
80 {"u:", &opt_unit, &opt_unitstr},
81 {NULL, NULL, NULL}
82 };
83
main(int argc,char * argv[])84 int main(int argc, char *argv[])
85 {
86 int lc;
87 int size = 128, num = 3, unit = 1;
88
89 tst_parse_opts(argc, argv, ksm_options, ksm_usage);
90 setup();
91 for (lc = 0; TEST_LOOPING(lc); lc++) {
92 tst_count = 0;
93 check_ksm_options(&size, &num, &unit);
94 write_memcg();
95 create_same_memory(size, num, unit);
96 }
97 cleanup();
98 tst_exit();
99 }
100
setup(void)101 void setup(void)
102 {
103 tst_require_root();
104
105 if (tst_kvercmp(2, 6, 32) < 0)
106 tst_brkm(TCONF, NULL, "2.6.32 or greater kernel required");
107 if (access(PATH_KSM, F_OK) == -1)
108 tst_brkm(TCONF, NULL, "KSM configuration is not enabled");
109
110 if (access(PATH_KSM "merge_across_nodes", F_OK) == 0) {
111 SAFE_FILE_SCANF(NULL, PATH_KSM "merge_across_nodes",
112 "%d", &merge_across_nodes);
113 SAFE_FILE_PRINTF(NULL, PATH_KSM "merge_across_nodes", "1");
114 }
115
116 save_max_page_sharing();
117
118 mount_mem("memcg", "cgroup", "memory", MEMCG_PATH, MEMCG_PATH_NEW);
119 tst_sig(FORK, DEF_HANDLER, NULL);
120 TEST_PAUSE;
121 }
122
cleanup(void)123 void cleanup(void)
124 {
125 if (access(PATH_KSM "merge_across_nodes", F_OK) == 0)
126 FILE_PRINTF(PATH_KSM "merge_across_nodes",
127 "%d", merge_across_nodes);
128
129 restore_max_page_sharing();
130
131 umount_mem(MEMCG_PATH, MEMCG_PATH_NEW);
132 }
133