diff --git a/mm/readahead.c b/mm/readahead.c
index 88ea0f29aac898fa4ce49f07cf1e56584f74e3b4..7f9bf588c93630800629b71201939866721ca4ca 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -21,8 +21,16 @@ void default_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
 }
 EXPORT_SYMBOL(default_unplug_io_fn);
 
+/*
+ * Convienent macros for min/max read-ahead pages.
+ * Note that MAX_RA_PAGES is rounded down, while MIN_RA_PAGES is rounded up.
+ * The latter is necessary for systems with large page size(i.e. 64k).
+ */
+#define MAX_RA_PAGES	(VM_MAX_READAHEAD*1024 / PAGE_CACHE_SIZE)
+#define MIN_RA_PAGES	DIV_ROUND_UP(VM_MIN_READAHEAD*1024, PAGE_CACHE_SIZE)
+
 struct backing_dev_info default_backing_dev_info = {
-	.ra_pages	= (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE,
+	.ra_pages	= MAX_RA_PAGES,
 	.state		= 0,
 	.capabilities	= BDI_CAP_MAP_COPY,
 	.unplug_io_fn	= default_unplug_io_fn,
@@ -51,7 +59,7 @@ static inline unsigned long get_max_readahead(struct file_ra_state *ra)
 
 static inline unsigned long get_min_readahead(struct file_ra_state *ra)
 {
-	return (VM_MIN_READAHEAD * 1024) / PAGE_CACHE_SIZE;
+	return MIN_RA_PAGES;
 }
 
 static inline void reset_ahead_window(struct file_ra_state *ra)