blob: 1d8b53cb516f618bf289b066f4f5a4b251d07337 [file] [log] [blame]
/*
* 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, &sectsize);
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);
}