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Subject[PATCH v4 4/8] swap: Unify normal/huge code path in swap_page_trans_huge_swapped()
Date
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

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>
---
mm/swapfile.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 833613e59ef7..97814a01170d 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -270,7 +270,9 @@ 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)
@@ -1492,9 +1494,6 @@ 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]))
--
2.16.4
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