1 /*
2 * Copyright (C) 2010-2017 Red Hat, Inc.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
12 * the GNU General Public License for more details.
13 *
14 * Kernel Samepage Merging (KSM)
15 *
16 * Basic tests were to start several programs with same and different
17 * memory contents and ensure only to merge the ones with the same
18 * contents. When changed the content of one of merged pages in a
19 * process and to the mode "unmerging", it should discard all merged
20 * pages there. Also tested it is possible to disable KSM. There are
21 * also command-line options to specify the memory allocation size, and
22 * number of processes have same memory contents so it is possible to
23 * test more advanced things like KSM + OOM etc.
24 *
25 * Prerequisites:
26 *
27 * 1) ksm and ksmtuned daemons need to be disabled. Otherwise, it could
28 * distrub the testing as they also change some ksm tunables depends
29 * on current workloads.
30 *
31 * The test steps are:
32 * - Check ksm feature and backup current run setting.
33 * - Change run setting to 1 - merging.
34 * - 3 memory allocation programs have the memory contents that 2 of
35 * them are all 'a' and one is all 'b'.
36 * - Check ksm statistics and verify the content.
37 * - 1 program changes the memory content from all 'a' to all 'b'.
38 * - Check ksm statistics and verify the content.
39 * - All programs change the memory content to all 'd'.
40 * - Check ksm statistics and verify the content.
41 * - Change one page of a process.
42 * - Check ksm statistics and verify the content.
43 * - Change run setting to 2 - unmerging.
44 * - Check ksm statistics and verify the content.
45 * - Change run setting to 0 - stop.
46 */
47
48 #include "config.h"
49 #include <sys/types.h>
50 #include <sys/stat.h>
51 #include <errno.h>
52 #include <fcntl.h>
53 #include <signal.h>
54 #include <stdio.h>
55 #include <unistd.h>
56 #include "mem.h"
57 #include "ksm_common.h"
58
59 #ifdef HAVE_NUMA_V2
60 #include <numaif.h>
61
verify_ksm(void)62 static void verify_ksm(void)
63 {
64 unsigned long nmask[MAXNODES / BITS_PER_LONG] = { 0 };
65 unsigned int node;
66
67 node = get_a_numa_node();
68 set_node(nmask, node);
69
70 if (set_mempolicy(MPOL_BIND, nmask, MAXNODES) == -1) {
71 if (errno != ENOSYS)
72 tst_brk(TBROK | TERRNO, "set_mempolicy");
73 else
74 tst_brk(TCONF, "set_mempolicy syscall is not "
75 "implemented on your system.");
76 }
77 create_same_memory(size, num, unit);
78
79 write_cpusets(tst_cg, node);
80 SAFE_CG_PRINTF(tst_cg, "cgroup.procs", "%d", getpid());
81 create_same_memory(size, num, unit);
82 SAFE_CG_PRINTF(tst_cg_drain, "cgroup.procs", "%d", getpid());
83 }
84
setup(void)85 static void setup(void)
86 {
87 parse_ksm_options(opt_sizestr, &size, opt_numstr, &num, opt_unitstr, &unit);
88
89 if (opt_sizestr && size > DEFAULT_MEMSIZE)
90 tst_set_max_runtime(32 * (size / DEFAULT_MEMSIZE));
91 }
92
93 static struct tst_test test = {
94 .needs_root = 1,
95 .forks_child = 1,
96 .options = (struct tst_option[]) {
97 {"n:", &opt_numstr, "Number of processes"},
98 {"s:", &opt_sizestr, "Memory allocation size in MB"},
99 {"u:", &opt_unitstr, "Memory allocation unit in MB"},
100 {}
101 },
102 .setup = setup,
103 .save_restore = (const struct tst_path_val[]) {
104 {"/sys/kernel/mm/ksm/run", NULL, TST_SR_TBROK},
105 {"/sys/kernel/mm/ksm/sleep_millisecs", NULL, TST_SR_TBROK},
106 {"/sys/kernel/mm/ksm/max_page_sharing", NULL,
107 TST_SR_SKIP_MISSING | TST_SR_TCONF_RO},
108 {"/sys/kernel/mm/ksm/merge_across_nodes", "1",
109 TST_SR_SKIP_MISSING | TST_SR_TCONF_RO},
110 {"/sys/kernel/mm/ksm/smart_scan", "0",
111 TST_SR_SKIP_MISSING | TST_SR_TBROK_RO},
112 {}
113 },
114 .needs_kconfigs = (const char *const[]){
115 "CONFIG_KSM=y",
116 NULL
117 },
118 .test_all = verify_ksm,
119 .max_runtime = 32,
120 .needs_cgroup_ctrls = (const char *const []){ "cpuset", NULL },
121 };
122
123 #else
124 TST_TEST_TCONF(NUMA_ERROR_MSG);
125 #endif
126