1/* readahead.c - preload files into disk cache. 2 * 3 * Copyright 2013 Rob Landley <rob@landley.net> 4 * 5 * No standard. 6 7USE_READAHEAD(NEWTOY(readahead, NULL, TOYFLAG_BIN)) 8 9config 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 22static 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 34void readahead_main(void) 35{ 36 loopfiles(toys.optargs, do_readahead); 37} 38