xref: /aosp_15_r20/external/toybox/toys/other/readahead.c (revision cf5a6c84e2b8763fc1a7db14496fd4742913b199)
1*cf5a6c84SAndroid Build Coastguard Worker /* readahead.c - preload files into disk cache.
2*cf5a6c84SAndroid Build Coastguard Worker  *
3*cf5a6c84SAndroid Build Coastguard Worker  * Copyright 2013 Rob Landley <[email protected]>
4*cf5a6c84SAndroid Build Coastguard Worker  *
5*cf5a6c84SAndroid Build Coastguard Worker  * No standard.
6*cf5a6c84SAndroid Build Coastguard Worker 
7*cf5a6c84SAndroid Build Coastguard Worker USE_READAHEAD(NEWTOY(readahead, NULL, TOYFLAG_BIN))
8*cf5a6c84SAndroid Build Coastguard Worker 
9*cf5a6c84SAndroid Build Coastguard Worker config READAHEAD
10*cf5a6c84SAndroid Build Coastguard Worker   bool "readahead"
11*cf5a6c84SAndroid Build Coastguard Worker   default y
12*cf5a6c84SAndroid Build Coastguard Worker   help
13*cf5a6c84SAndroid Build Coastguard Worker     usage: readahead FILE...
14*cf5a6c84SAndroid Build Coastguard Worker 
15*cf5a6c84SAndroid Build Coastguard Worker     Preload files into disk cache.
16*cf5a6c84SAndroid Build Coastguard Worker */
17*cf5a6c84SAndroid Build Coastguard Worker 
18*cf5a6c84SAndroid Build Coastguard Worker #include "toys.h"
19*cf5a6c84SAndroid Build Coastguard Worker 
do_readahead(int fd,char * name)20*cf5a6c84SAndroid Build Coastguard Worker static void do_readahead(int fd, char *name)
21*cf5a6c84SAndroid Build Coastguard Worker {
22*cf5a6c84SAndroid Build Coastguard Worker   int rc;
23*cf5a6c84SAndroid Build Coastguard Worker 
24*cf5a6c84SAndroid Build Coastguard Worker   // Since including fcntl.h doesn't give us the wrapper, use the syscall.
25*cf5a6c84SAndroid Build Coastguard Worker   // 32 bits takes LO/HI offset (we don't care about endianness of 0).
26*cf5a6c84SAndroid Build Coastguard Worker   if (sizeof(long) == 4) rc = syscall(__NR_readahead, fd, 0, 0, INT_MAX);
27*cf5a6c84SAndroid Build Coastguard Worker   else rc = syscall(__NR_readahead, fd, 0, INT_MAX);
28*cf5a6c84SAndroid Build Coastguard Worker 
29*cf5a6c84SAndroid Build Coastguard Worker   if (rc) perror_msg("readahead: %s", name);
30*cf5a6c84SAndroid Build Coastguard Worker }
31*cf5a6c84SAndroid Build Coastguard Worker 
readahead_main(void)32*cf5a6c84SAndroid Build Coastguard Worker void readahead_main(void)
33*cf5a6c84SAndroid Build Coastguard Worker {
34*cf5a6c84SAndroid Build Coastguard Worker   loopfiles(toys.optargs, do_readahead);
35*cf5a6c84SAndroid Build Coastguard Worker }
36