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authorRob Landley <rob@landley.net>2013-02-24 12:51:40 -0600
committerRob Landley <rob@landley.net>2013-02-24 12:51:40 -0600
commit53832006245010487d8d12599ce011d67bf19f94 (patch)
tree5194c129d58ce7ab021c6d06159a02203311cd5b /toys/other
parent9559c2c4a0e99975782fa283c77f5a22a50e1bff (diff)
downloadtoybox-53832006245010487d8d12599ce011d67bf19f94.tar.gz
Add readahead.
Diffstat (limited to 'toys/other')
-rw-r--r--toys/other/readahead.c37
1 files changed, 37 insertions, 0 deletions
diff --git a/toys/other/readahead.c b/toys/other/readahead.c
new file mode 100644
index 00000000..4edd6516
--- /dev/null
+++ b/toys/other/readahead.c
@@ -0,0 +1,37 @@
+/* readahead.c - preload files into disk cache.
+ *
+ * Copyright 2013 Rob Landley <rob@landley.net>
+ *
+ * No standard.
+
+USE_READAHEAD(NEWTOY(readahead, NULL, TOYFLAG_BIN))
+
+config READAHEAD
+ bool "readahead"
+ default y
+ help
+ usage: readahead FILE...
+
+ Preload files into disk cache.
+*/
+
+#include "toys.h"
+
+#include <sys/syscall.h>
+
+static void do_readahead(int fd, char *name)
+{
+ int rc;
+
+ // Since including fcntl.h doesn't give us the wrapper, use the syscall.
+ // 32 bits takes LO/HI offset (we don't care about endianness of 0).
+ if (sizeof(long) == 4) rc = syscall(__NR_readahead, fd, 0, 0, INT_MAX);
+ else rc = syscall(__NR_readahead, fd, 0, INT_MAX);
+
+ if (rc) perror_msg("readahead: %s", name);
+}
+
+void readahead_main(void)
+{
+ loopfiles(toys.optargs, do_readahead);
+}