[PATCH] SwapMig: add_to_swap() avoid atomic allocations

Add gfp_mask to add_to_swap

add_to_swap does allocations with GFP_ATOMIC in order not to interfere with
swapping.  During migration we may have use add_to_swap extensively which may
lead to out of memory errors.

This patch makes add_to_swap take a parameter that specifies the gfp mask.
The page migration code can then make add_to_swap use GFP_KERNEL.

Signed-off-by: Hirokazu Takahashi <taka@valinux.co.jp>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/mm/swap_state.c b/mm/swap_state.c
index fc2aecb70a95..7b09ac503fec 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -141,7 +141,7 @@ void __delete_from_swap_cache(struct page *page)
  * Allocate swap space for the page and add the page to the
  * swap cache.  Caller needs to hold the page lock. 
  */
-int add_to_swap(struct page * page)
+int add_to_swap(struct page * page, gfp_t gfp_mask)
 {
         swp_entry_t entry;
         int err;
@@ -166,7 +166,7 @@ int add_to_swap(struct page * page)
                  * Add it to the swap cache and mark it dirty
                  */
                 err = __add_to_swap_cache(page, entry,
-                                GFP_ATOMIC|__GFP_NOMEMALLOC|__GFP_NOWARN);
+                                gfp_mask|__GFP_NOMEMALLOC|__GFP_NOWARN);
 
                 switch (err) {
                 case 0:                         /* Success */