[PATCH 2/3] swap: call free_swap_slot() in __swap_entry_free()

From: Huang Ying
Date: Mon Aug 27 2018 - 03:55:47 EST


This is a code cleanup patch without functionality change.

Originally, when __swap_entry_free() is called, and its return value
is 0, free_swap_slot() will always be called to free the swap entry to
the per-CPU pool. So move the call to free_swap_slot() to
__swap_entry_free() to simplify the code.

Signed-off-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Shaohua Li <shli@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
---
mm/swapfile.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 409926079607..ef974bbd7715 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1241,6 +1241,8 @@ static unsigned char __swap_entry_free(struct swap_info_struct *p,
ci = lock_cluster_or_swap_info(p, offset);
usage = __swap_entry_free_locked(p, offset, usage);
unlock_cluster_or_swap_info(p, ci);
+ if (!usage)
+ free_swap_slot(entry);

return usage;
}
@@ -1271,10 +1273,8 @@ void swap_free(swp_entry_t entry)
struct swap_info_struct *p;

p = _swap_info_get(entry);
- if (p) {
- if (!__swap_entry_free(p, entry, 1))
- free_swap_slot(entry);
- }
+ if (p)
+ __swap_entry_free(p, entry, 1);
}

/*
@@ -1705,8 +1705,6 @@ int free_swap_and_cache(swp_entry_t entry)
!swap_page_trans_huge_swapped(p, entry))
__try_to_reclaim_swap(p, swp_offset(entry),
TTRS_UNMAPPED | TTRS_FULL);
- else if (!count)
- free_swap_slot(entry);
}
return p != NULL;
}
--
2.16.4