From afa4711ef1399beb60964dcb2cd0369dfb0ac20a Mon Sep 17 00:00:00 2001 From: Huang Ying Date: Tue, 21 Aug 2018 21:52:09 -0700 Subject: [PATCH] mm/swapfile.c: use swap_count() in swap_page_trans_huge_swapped() In swap_page_trans_huge_swapped(), to identify whether there's any page table mapping for a 4k sized swap entry, "si->swap_map[i] != SWAP_HAS_CACHE" is used. This works correctly now, because all users of the function will only call it after checking SWAP_HAS_CACHE. But as pointed out by Daniel, it is better to use "swap_count(map[i])" here, because it works for "map[i] == 0" case too. And this makes the implementation more consistent between normal and huge swap entry. Link: http://lkml.kernel.org/r/20180720071845.17920-4-ying.huang@intel.com Signed-off-by: "Huang, Ying" Suggested-and-reviewed-by: Daniel Jordan Acked-by: Dave Hansen Cc: Michal Hocko Cc: Johannes Weiner Cc: Shaohua Li Cc: Hugh Dickins Cc: Minchan Kim Cc: Rik van Riel Cc: Dan Williams Cc: Matthew Wilcox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/swapfile.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/swapfile.c b/mm/swapfile.c index 618358ad464b..c291400c4463 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1429,12 +1429,12 @@ static bool swap_page_trans_huge_swapped(struct swap_info_struct *si, ci = lock_cluster_or_swap_info(si, offset); if (!ci || !cluster_is_huge(ci)) { - if (map[roffset] != SWAP_HAS_CACHE) + if (swap_count(map[roffset])) ret = true; goto unlock_out; } for (i = 0; i < SWAPFILE_CLUSTER; i++) { - if (map[offset + i] != SWAP_HAS_CACHE) { + if (swap_count(map[offset + i])) { ret = true; break; } -- GitLab