| /* |
| * Copyright (c) 2004-2005 Silicon Graphics, Inc. |
| * All Rights Reserved. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License as |
| * published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it would be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| #include "command.h" |
| #include "input.h" |
| #include <sys/mman.h> |
| #include "init.h" |
| #include "io.h" |
| |
| static cmdinfo_t madvise_cmd; |
| |
| static void |
| madvise_help(void) |
| { |
| printf(_( |
| "\n" |
| " advise the page cache about access patterns expected for a mapping\n" |
| "\n" |
| " Modifies page cache behavior when operating on the current mapping.\n" |
| " The range arguments are required by some advise commands ([*] below).\n" |
| " With no arguments, the POSIX_MADV_NORMAL advice is implied.\n" |
| " -d -- don't need these pages (POSIX_MADV_DONTNEED) [*]\n" |
| " -r -- expect random page references (POSIX_MADV_RANDOM)\n" |
| " -s -- expect sequential page references (POSIX_MADV_SEQUENTIAL)\n" |
| " -w -- will need these pages (POSIX_MADV_WILLNEED) [*]\n" |
| " Notes:\n" |
| " NORMAL sets the default readahead setting on the file.\n" |
| " RANDOM sets the readahead setting on the file to zero.\n" |
| " SEQUENTIAL sets double the default readahead setting on the file.\n" |
| " WILLNEED forces the maximum readahead.\n" |
| "\n")); |
| } |
| |
| int |
| madvise_f( |
| int argc, |
| char **argv) |
| { |
| off64_t offset, llength; |
| size_t length; |
| void *start; |
| int advise = MADV_NORMAL, c; |
| size_t blocksize, sectsize; |
| |
| while ((c = getopt(argc, argv, "drsw")) != EOF) { |
| switch (c) { |
| case 'd': /* Don't need these pages */ |
| advise = MADV_DONTNEED; |
| break; |
| case 'r': /* Expect random page references */ |
| advise = MADV_RANDOM; |
| break; |
| case 's': /* Expect sequential page references */ |
| advise = MADV_SEQUENTIAL; |
| break; |
| case 'w': /* Will need these pages */ |
| advise = MADV_WILLNEED; |
| break; |
| default: |
| return command_usage(&madvise_cmd); |
| } |
| } |
| |
| if (optind == argc) { |
| offset = mapping->offset; |
| length = mapping->length; |
| } else if (optind == argc - 2) { |
| init_cvtnum(&blocksize, §size); |
| offset = cvtnum(blocksize, sectsize, argv[optind]); |
| if (offset < 0) { |
| printf(_("non-numeric offset argument -- %s\n"), |
| argv[optind]); |
| return 0; |
| } |
| optind++; |
| llength = cvtnum(blocksize, sectsize, argv[optind]); |
| if (llength < 0) { |
| printf(_("non-numeric length argument -- %s\n"), |
| argv[optind]); |
| return 0; |
| } else if (llength > (size_t)llength) { |
| printf(_("length argument too large -- %lld\n"), |
| (long long)llength); |
| return 0; |
| } else |
| length = (size_t)llength; |
| } else { |
| return command_usage(&madvise_cmd); |
| } |
| |
| start = check_mapping_range(mapping, offset, length, 1); |
| if (!start) |
| return 0; |
| |
| if (madvise(start, length, advise) < 0) { |
| perror("madvise"); |
| return 0; |
| } |
| return 0; |
| } |
| |
| void |
| madvise_init(void) |
| { |
| madvise_cmd.name = "madvise"; |
| madvise_cmd.altname = "ma"; |
| madvise_cmd.cfunc = madvise_f; |
| madvise_cmd.argmin = 0; |
| madvise_cmd.argmax = -1; |
| madvise_cmd.flags = CMD_NOFILE_OK | CMD_FOREIGN_OK; |
| madvise_cmd.args = _("[-drsw] [off len]"); |
| madvise_cmd.oneline = _("give advice about use of memory"); |
| madvise_cmd.help = madvise_help; |
| |
| add_command(&madvise_cmd); |
| } |