1 /* 2 * This is a reproducer copied from one of LKML patch submission, 3 * which subject is 4 * 5 * [PATCH] mlock: revert the optimization for dirtying pages and triggering writeback. 6 * 7 * "In 5ecfda0, we do some optimization in mlock, but it causes 8 * a very basic test case(attached below) of mlock to fail. So 9 * this patch revert it with some tiny modification so that it 10 * apply successfully with the lastest 38-rc2 kernel." 11 * 12 * Copyright (C) 2010 Red Hat, Inc. 13 * This program is free software; you can redistribute it and/or 14 * modify it under the terms of version 2 of the GNU General Public 15 * License as published by the Free Software Foundation. 16 * 17 * This program is distributed in the hope that it would be useful, 18 * but WITHOUT ANY WARRANTY; without even the implied warranty of 19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 20 * 21 * Further, this software is distributed without any warranty that it 22 * is free of the rightful claim of any third person regarding 23 * infringement or the like. Any license provided herein, whether 24 * implied or otherwise, applies only to this software file. Patent 25 * licenses, if any, provided herein do not apply to combinations of 26 * this program with other software, or any other product whatsoever. 27 * 28 * You should have received a copy of the GNU General Public License 29 * along with this program; if not, write the Free Software 30 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 31 * 02110-1301, USA. 32 */ 33 #include "test.h" 34 #include "config.h" 35 36 char *TCID = "mlock04"; 37 int TST_TOTAL = 1; 38 39 #include <sys/mman.h> 40 #include <stdio.h> 41 #include <sys/types.h> 42 #include <sys/stat.h> 43 #include <errno.h> 44 #include <fcntl.h> 45 #include <unistd.h> 46 #include <sys/types.h> 47 48 int fd, file_len = 40960; 49 char *testfile = "test_mlock"; 50 51 static void setup(void); 52 static void cleanup(void); 53 54 int main(void) 55 { 56 char *buf; 57 int lc; 58 59 setup(); 60 61 for (lc = 0; TEST_LOOPING(lc); lc++) { 62 buf = mmap(NULL, file_len, PROT_WRITE, MAP_SHARED, fd, 0); 63 64 if (buf == MAP_FAILED) 65 tst_brkm(TBROK | TERRNO, cleanup, "mmap"); 66 67 if (mlock(buf, file_len) == -1) 68 tst_brkm(TBROK | TERRNO, cleanup, "mlock"); 69 70 tst_resm(TINFO, "locked %d bytes from %p", file_len, buf); 71 72 if (munlock(buf, file_len) == -1) 73 tst_brkm(TBROK | TERRNO, cleanup, "munlock"); 74 75 if (munmap(buf, file_len) == -1) 76 tst_brkm(TBROK | TERRNO, cleanup, "munmap"); 77 } 78 79 tst_resm(TPASS, "test succeeded."); 80 81 cleanup(); 82 83 tst_exit(); 84 } 85 86 static void setup(void) 87 { 88 tst_tmpdir(); 89 90 fd = open(testfile, O_CREAT | O_RDWR, S_IRUSR | S_IWUSR); 91 if (fd == -1) 92 tst_brkm(TBROK | TERRNO, cleanup, "open"); 93 94 if (ftruncate(fd, file_len) == -1) 95 tst_brkm(TBROK | TERRNO, cleanup, "ftruncate"); 96 97 TEST_PAUSE; 98 } 99 100 static void cleanup(void) 101 { 102 close(fd); 103 104 tst_rmdir(); 105 } 106