mm/swapfile.c: unify normal/huge code path in swap_page_trans_huge_swapped()

yhuang-intel · torvalds · commit 33ee011e5656 · 2018-08-22T10:52:43.000-07:00
As suggested by Dave, we should unify the code path for normal and huge swap support if possible to avoid duplicated code, bugs, etc. and make it easier to review code. In this patch, the normal/huge code path in swap_page_trans_huge_swapped() is unified, the added and removed lines are same. And the binary size is kept almost same when CONFIG_TRANSPARENT_HUGEPAGE=n. text data bss dec hex filename base: 24179 2028 340 26547 67b3 mm/swapfile.o unified: 24215 2028 340 26583 67d7 mm/swapfile.o Link: http://lkml.kernel.org/r/20180720071845.17920-5-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Suggested-and-acked-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Shaohua Li <shli@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/swapfile.c b/mm/swapfile.c
@@ -269,7 +269,9 @@ static inline void cluster_set_null(struct swap_cluster_info *info)
 
 static inline bool cluster_is_huge(struct swap_cluster_info *info)
 {
-	return info->flags & CLUSTER_FLAG_HUGE;
+	if (IS_ENABLED(CONFIG_THP_SWAP))
+		return info->flags & CLUSTER_FLAG_HUGE;
+	return false;
 }
 
 static inline void cluster_clear_huge(struct swap_cluster_info *info)
@@ -1424,9 +1426,6 @@ static bool swap_page_trans_huge_swapped(struct swap_info_struct *si,
 	int i;
 	bool ret = false;
 
-	if (!IS_ENABLED(CONFIG_THP_SWAP))
-		return swap_swapcount(si, entry) != 0;
-
 	ci = lock_cluster_or_swap_info(si, offset);
 	if (!ci || !cluster_is_huge(ci)) {
 		if (swap_count(map[roffset]))
