Commit 93e06c7a authored by Shaohua Li's avatar Shaohua Li Committed by Linus Torvalds

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.comSigned-off-by: default avatarShaohua Li <shli@fb.com>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Acked-by: default avatarHillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: default avatarMinchan 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent eb94a878
...@@ -650,13 +650,7 @@ madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev, ...@@ -650,13 +650,7 @@ madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev,
case MADV_WILLNEED: case MADV_WILLNEED:
return madvise_willneed(vma, prev, start, end); return madvise_willneed(vma, prev, start, end);
case MADV_FREE: case MADV_FREE:
/* return madvise_free(vma, prev, start, end);
* 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: case MADV_DONTNEED:
return madvise_dontneed(vma, prev, start, end); return madvise_dontneed(vma, prev, start, end);
default: default:
......
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