[patch 054/163] mm/swap_slots.c: simplify alloc_swap_slot_cache()

Andrew Morton
2020-08-07T06:20:08Z

From: Zhen Lei <thunder.leizhen@huawei.com>
Subject: mm/swap_slots.c: simplify alloc_swap_slot_cache()

Patch series "clean up some functions in mm/swap_slots.c".

When I studied the code of mm/swap_slots.c, I found some places can be
improved.

This patch (of 3):

Both "slots" and "slots_ret" are only need to be freed when cache already
allocated. Make them closer, seems more clear.

No functional change.

Link: http://lkml.kernel.org/r/20200430061143.450-1-thunder.leizhen@huawei.com
Link: http://lkml.kernel.org/r/20200430061143.450-2-thunder.leizhen@huawei.com
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

mm/swap_slots.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)

--- a/mm/swap_slots.c~mm-swap-simplify-alloc_swap_slot_cache
+++ a/mm/swap_slots.c
@@ -136,9 +136,16 @@ static int alloc_swap_slot_cache(unsigne

mutex_lock(&swap_slots_cache_mutex);
cache = &per_cpu(swp_slots, cpu);
- if (cache->slots || cache->slots_ret)
+ if (cache->slots || cache->slots_ret) {
/* cache already allocated */
- goto out;
+ mutex_unlock(&swap_slots_cache_mutex);
+
+ kvfree(slots);
+ kvfree(slots_ret);
+
+ return 0;
+ }
+
if (!cache->lock_initialized) {
mutex_init(&cache->alloc_lock);
spin_lock_init(&cache->free_lock);
@@ -155,15 +162,8 @@ static int alloc_swap_slot_cache(unsigne
*/
mb();
cache->slots = slots;
- slots = NULL;
cache->slots_ret = slots_ret;
- slots_ret = NULL;
-out:
mutex_unlock(&swap_slots_cache_mutex);
- if (slots)
- kvfree(slots);
- if (slots_ret)
- kvfree(slots_ret);
return 0;
}

_