Commit 93e06c7a authored May 03, 2017 by Shaohua Li Committed by Linus Torvalds May 03, 2017

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 <shli@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent eb94a878

mm/madvise.c

+1 −7

Original line number	Diff line number	Diff line
		@@ -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 */
		case MADV_DONTNEED:
		return madvise_dontneed(vma, prev, start, end);
		default: