1 /* readahead.c - preload files into disk cache.
2 *
3 * Copyright 2013 Rob Landley <rob@landley.net>
4 *
5 * No standard.
6
7 USE_READAHEAD(NEWTOY(readahead, NULL, TOYFLAG_BIN))
8
9 config READAHEAD
10 bool "readahead"
11 default y
12 help
13 usage: readahead FILE...
14
15 Preload files into disk cache.
16 */
17
18 #include "toys.h"
19
20 #include <sys/syscall.h>
21
do_readahead(int fd,char * name)22 static void do_readahead(int fd, char *name)
23 {
24 int rc;
25
26 // Since including fcntl.h doesn't give us the wrapper, use the syscall.
27 // 32 bits takes LO/HI offset (we don't care about endianness of 0).
28 if (sizeof(long) == 4) rc = syscall(__NR_readahead, fd, 0, 0, INT_MAX);
29 else rc = syscall(__NR_readahead, fd, 0, INT_MAX);
30
31 if (rc) perror_msg("readahead: %s", name);
32 }
33
readahead_main(void)34 void readahead_main(void)
35 {
36 loopfiles(toys.optargs, do_readahead);
37 }
38