--- include/linux/mm.h

+++ include/linux/mm.h

@@ -1509,8 +1509,10 @@ int write_one_page(struct page *page, in

void task_dirty_inc(struct task_struct *tsk);

/* readahead.c */

-#define VM_MAX_READAHEAD 128 /* kbytes */

-#define VM_MIN_READAHEAD 16 /* kbytes (includes current page) */

+#define VM_MAX_READAHEAD 2048 /* kbytes */

+#define VM_MIN_READAHEAD 64 /* kbytes (includes current page) */

+

+extern unsigned long max_readahead_pages;

int force_page_cache_readahead(struct address_space *mapping, struct file *filp,

pgoff_t offset, unsigned long nr_to_read);