| Message ID | 20200430061143.450-4-thunder.leizhen@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | clean up some functions in mm/swap_slots.c | expand |
On 4/29/20 11:11 PM, Zhen Lei wrote: > 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. > > Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> > --- > mm/swap_slots.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/mm/swap_slots.c b/mm/swap_slots.c > index b40394473a3c..3e6453573a89 100644 > --- a/mm/swap_slots.c > +++ b/mm/swap_slots.c > @@ -46,8 +46,7 @@ static void __drain_swap_slots_cache(unsigned int type); > 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) Yes, swap_slot_cache_enabled does imply swap_slot_cache_initialized in current code. So checking swap_slot_cache_enabled is enough here. > #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) This simplification is okay. !swap_slot_cache_initialize implies !swap_slot_cache_enabled. So only !swap_slot_cache_enabled needs to be checked. > return false; > > pages = get_nr_swap_pages(); > Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
diff --git a/mm/swap_slots.c b/mm/swap_slots.c index b40394473a3c..3e6453573a89 100644 --- a/mm/swap_slots.c +++ b/mm/swap_slots.c @@ -46,8 +46,7 @@ static void __drain_swap_slots_cache(unsigned int type); 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();
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. Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> --- mm/swap_slots.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)