[PATCH] migration: remove unnecessary PageSwapCache checks

Remove two unnecessary PageSwapCache checks.  The page refcount is raised
and therefore page migration cannot occur in both functions.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

mm/shmem.c

@@ -1081,14 +1081,6 @@ static int shmem_getpage(struct inode *inode, unsigned long idx,
 			page_cache_release(swappage);
 			goto repeat;
 		}
-		if (!PageSwapCache(swappage)) {
-			/* Page migration has occured */
-			shmem_swp_unmap(entry);
-			spin_unlock(&info->lock);
-			unlock_page(swappage);
-			page_cache_release(swappage);
-			goto repeat;
-		}
 		if (PageWriteback(swappage)) {
 			shmem_swp_unmap(entry);
 			spin_unlock(&info->lock);

mm/swapfile.c

@@ -716,7 +716,6 @@ static int try_to_unuse(unsigned int type)
 		 */
 		swap_map = &si->swap_map[i];
 		entry = swp_entry(type, i);
-again:
 		page = read_swap_cache_async(entry, NULL, 0);
 		if (!page) {
 			/*
@@ -751,12 +750,6 @@ static int try_to_unuse(unsigned int type)
 		wait_on_page_locked(page);
 		wait_on_page_writeback(page);
 		lock_page(page);
-		if (!PageSwapCache(page)) {
-			/* Page migration has occured */
-			unlock_page(page);
-			page_cache_release(page);
-			goto again;
-		}
 		wait_on_page_writeback(page);
 
 		/*