mm: enable MADV_FREE for swapless system

Now MADV_FREE pages can be easily reclaimed even for swapless system. We can safely enable MADV_FREE for all systems. Link: http://lkml.kernel.org/r/155648585589300bfae1d45078e7aebb3d988b87.1487965799.git.shli@fb.com Signed-off-by: Shaohua Li <[email protected]> Acked-by: Johannes Weiner <[email protected]> Acked-by: Michal Hocko <[email protected]> Acked-by: Hillf Danton <[email protected]> Acked-by: Minchan Kim <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Mel Gorman <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
CamonZ · May 3, 2017 · 93e06c7 · 93e06c7
1 parent eb94a87
commit 93e06c7
Showing 1 changed file with 1 addition and 7 deletions.
diff --git a/mm/madvise.c b/mm/madvise.c
@@ -650,13 +650,7 @@ madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev,
 	case MADV_WILLNEED:
 		return madvise_willneed(vma, prev, start, end);
 	case MADV_FREE:
-		/*
-		 * XXX: In this implementation, MADV_FREE works like
-		 * MADV_DONTNEED on swapless system or full swap.
-		 */
-		if (get_nr_swap_pages() > 0)
-			return madvise_free(vma, prev, start, end);
-		/* passthrough */
+		return madvise_free(vma, prev, start, end);
 	case MADV_DONTNEED:
 		return madvise_dontneed(vma, prev, start, end);
 	default: