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) for Memory Resource Controller 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 <sys/types.h> 49 #include <sys/mman.h> 50 #include <sys/stat.h> 51 #include <sys/wait.h> 52 #include <errno.h> 53 #include <fcntl.h> 54 #include <signal.h> 55 #include <stdio.h> 56 #include <stdlib.h> 57 #include <string.h> 58 #include <unistd.h> 59 #include "mem.h" 60 #include "ksm_common.h" 61 62 static int memcg_mounted; 63 64 static void verify_ksm(void) 65 { 66 write_memcg(); 67 create_same_memory(size, num, unit); 68 } 69 70 static void setup(void) 71 { 72 if (access(PATH_KSM, F_OK) == -1) 73 tst_brk(TCONF, "KSM configuration is not enabled"); 74 75 if (access(PATH_KSM "merge_across_nodes", F_OK) == 0) { 76 SAFE_FILE_SCANF(PATH_KSM "merge_across_nodes", 77 "%d", &merge_across_nodes); 78 SAFE_FILE_PRINTF(PATH_KSM "merge_across_nodes", "1"); 79 } 80 81 parse_ksm_options(opt_sizestr, &size, opt_numstr, &num, opt_unitstr, &unit); 82 mount_mem("memcg", "cgroup", "memory", MEMCG_PATH, MEMCG_PATH_NEW); 83 memcg_mounted = 1; 84 } 85 86 static void cleanup(void) 87 { 88 if (access(PATH_KSM "merge_across_nodes", F_OK) == 0) 89 FILE_PRINTF(PATH_KSM "merge_across_nodes", 90 "%d", merge_across_nodes); 91 92 if (memcg_mounted) 93 umount_mem(MEMCG_PATH, MEMCG_PATH_NEW); 94 } 95 96 static struct tst_test test = { 97 .needs_root = 1, 98 .forks_child = 1, 99 .options = ksm_options, 100 .setup = setup, 101 .cleanup = cleanup, 102 .save_restore = save_restore, 103 .test_all = verify_ksm, 104 .min_kver = "2.6.32", 105 }; 106
