--- 867f9dd82dcde9d5c11f49bde159c3c6a0276c4e
+++ e18a5c100486a3c0f648294ee44f3760aacfafbf
@@ -17,6 +17,7 @@
 #include <linux/task_io_accounting_ops.h>
 #include <linux/pagevec.h>
 #include <linux/pagemap.h>
+#include <linux/swap.h>
 
 /*
  * Initialise a struct file's readahead state.  Assumes that the caller has
@@ -107,7 +108,7 @@ int read_cache_pages(struct address_spac
 EXPORT_SYMBOL(read_cache_pages);
 
 static int read_pages(struct address_space *mapping, struct file *filp,
-		struct list_head *pages, unsigned nr_pages)
+		struct list_head *pages, unsigned nr_pages, int tail)
 {
 	struct blk_plug plug;
 	unsigned page_idx;
@@ -125,8 +126,8 @@ static int read_pages(struct address_spa
 	for (page_idx = 0; page_idx < nr_pages; page_idx++) {
 		struct page *page = list_to_page(pages);
 		list_del(&page->lru);
-		if (!add_to_page_cache_lru(page, mapping,
-					page->index, GFP_KERNEL)) {
+		if (!__add_to_page_cache_lru(page, mapping,
+					page->index, GFP_KERNEL, tail)) {
 			mapping->a_ops->readpage(filp, page);
 		}
 		page_cache_release(page);
@@ -139,6 +140,28 @@ out:
 	return ret;
 }
 
+static inline int nr_mapped(void)
+{
+	return global_page_state(NR_FILE_MAPPED) +
+		global_page_state(NR_ANON_PAGES);
+}
+
+/*
+ * This examines how large in pages a file size is and returns 1 if it is
+ * more than half the unmapped ram. Avoid doing read_page_state which is
+ * expensive unless we already know it is likely to be large enough.
+ */
+static int large_isize(unsigned long nr_pages)
+{
+	if (nr_pages * 6 > vm_total_pages) {
+		 unsigned long unmapped_ram = vm_total_pages - nr_mapped();
+
+		if (nr_pages * 2 > unmapped_ram)
+			return 1;
+	}
+	return 0;
+}
+
 /*
  * __do_page_cache_readahead() actually reads a chunk of disk.  It allocates all
  * the pages first, then submits them all for I/O. This avoids the very bad
@@ -196,7 +219,8 @@ __do_page_cache_readahead(struct address
 	 * will then handle the error.
 	 */
 	if (ret)
-		read_pages(mapping, filp, &page_pool, ret);
+		read_pages(mapping, filp, &page_pool, ret,
+			   large_isize(end_index));
 	BUG_ON(!list_empty(&page_pool));
 out:
 	return ret;