Re: [PATCH v4 -mm] make swapin readahead skip over holes

On 01/25/2012 08:23 PM, Andrew Morton wrote:

Just to show that I'm paying attention...

quoted

--- a/mm/swap_state.c
+++ b/mm/swap_state.c

@@ -382,25 +382,23 @@ struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
  struct page *swapin_readahead(swp_entry_t entry, gfp_t gfp_mask,
  			struct vm_area_struct *vma, unsigned long addr)
  {
-	int nr_pages;
  	struct page *page;
-	unsigned long offset;
-	unsigned long end_offset;
+	unsigned long offset = swp_offset(entry);
+	unsigned long start_offset, end_offset;
+	unsigned long mask = (1<<  page_cluster) - 1;

This is broken for page_cluster>  31.  Fix:

I don't know who would want to do their swapins in chunks
of 8GB or large at a time, but still a good catch.

Want me to send in a v5, or do you prefer to merge a -fix
patch in your tree?

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