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this_cpu: Use this_cpu ops for VM statistics 

Using per cpu atomics for the vm statistics reduces their overhead.
And in the case of x86 we are guaranteed that they will never race even
in the lax form used for vm statistics.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Christoph Lameter 2009-10-03 19:48:23 +09:00 committed by Tejun Heo
parent 0b44f4861f
commit 4dac3e9884
1 changed files with 4 additions and 6 deletions
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10
include/linux/vmstat.h
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@ -76,24 +76,22 @@ DECLARE_PER_CPU(struct vm_event_state, vm_event_states);
static inline void __count_vm_event(enum vm_event_item item) static inline void __count_vm_event(enum vm_event_item item)
{ {
__get_cpu_var(vm_event_states).event[item]++; __this_cpu_inc(per_cpu_var(vm_event_states).event[item]);
} }
static inline void count_vm_event(enum vm_event_item item) static inline void count_vm_event(enum vm_event_item item)
{ {
get_cpu_var(vm_event_states).event[item]++; this_cpu_inc(per_cpu_var(vm_event_states).event[item]);
put_cpu();
} }
static inline void __count_vm_events(enum vm_event_item item, long delta) static inline void __count_vm_events(enum vm_event_item item, long delta)
{ {
__get_cpu_var(vm_event_states).event[item] += delta; __this_cpu_add(per_cpu_var(vm_event_states).event[item], delta);
} }
static inline void count_vm_events(enum vm_event_item item, long delta) static inline void count_vm_events(enum vm_event_item item, long delta)
{ {
get_cpu_var(vm_event_states).event[item] += delta; this_cpu_add(per_cpu_var(vm_event_states).event[item], delta);
put_cpu();
} }
extern void all_vm_events(unsigned long *); extern void all_vm_events(unsigned long *);