The patch titled
Subject: mm/swap_slots.c: remove redundant check for swap_slot_cache_initialized
has been added to the -mm tree. Its filename is
mm-swap-remove-redundant-check-for-swap_slot_cache_initialized.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-swap-remove-redundant-check-for-swap_slot_cache_initialized.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-swap-remove-redundant-check-for-swap_slot_cache_initialized.patch
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------------------------------------------------------
From: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
Subject: mm/swap_slots.c: remove redundant check for swap_slot_cache_initialized
Because enable_swap_slots_cache can only become true in
enable_swap_slots_cache(), and depends on swap_slot_cache_initialized is
true before. That means, when enable_swap_slots_cache is true,
swap_slot_cache_initialized is true also.
So the condition:
"swap_slot_cache_enabled && swap_slot_cache_initialized"
can be reduced to "swap_slot_cache_enabled"
And in mathematics:
"!swap_slot_cache_enabled || !swap_slot_cache_initialized"
is equal to "!(swap_slot_cache_enabled && swap_slot_cache_initialized)"
So no functional change.
Link: http://lkml.kernel.org/r/20200430061143.450-4-thunder.leizhen@xxxxxxxxxx
Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
Acked-by: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/swap_slots.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
--- a/mm/swap_slots.c~mm-swap-remove-redundant-check-for-swap_slot_cache_initialized
+++ a/mm/swap_slots.c
@@ -46,8 +46,7 @@ static void __drain_swap_slots_cache(uns
static void deactivate_swap_slots_cache(void);
static void reactivate_swap_slots_cache(void);
-#define use_swap_slot_cache (swap_slot_cache_active && \
- swap_slot_cache_enabled && swap_slot_cache_initialized)
+#define use_swap_slot_cache (swap_slot_cache_active && swap_slot_cache_enabled)
#define SLOTS_CACHE 0x1
#define SLOTS_CACHE_RET 0x2
@@ -94,7 +93,7 @@ static bool check_cache_active(void)
{
long pages;
- if (!swap_slot_cache_enabled || !swap_slot_cache_initialized)
+ if (!swap_slot_cache_enabled)
return false;
pages = get_nr_swap_pages();
_
Patches currently in -mm which might be from thunder.leizhen@xxxxxxxxxx are
mm-swap-simplify-alloc_swap_slot_cache.patch
mm-swap-simplify-enable_swap_slots_cache.patch
mm-swap-remove-redundant-check-for-swap_slot_cache_initialized.patch
mm-mmap-optimize-a-branch-judgment-in-ksys_mmap_pgoff.patch
