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perf, cpu hotplug: Use cached value of smp_processor_id()

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The perf_cpu_notifier() macro invokes smp_processor_id()
multiple times. Optimize it by using a local variable.

Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: peterz@infradead.org
Cc: acme@ghostprotocols.net
Link: http://lkml.kernel.org/r/20121016075817.3572.76733.stgit@srivatsabhat.in.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Srivatsa S. Bhat 2012-10-16 13:28:17 +05:30 committed by Ingo Molnar
parent 6760bca9fd
commit c13d38e4a1
1 changed files with 4 additions and 3 deletions
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7
include/linux/perf_event.h
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@ -803,15 +803,16 @@ static inline void perf_event_task_tick(void) { }
do { \
static struct notifier_block fn##_nb __cpuinitdata = \
{ .notifier_call = fn, .priority = CPU_PRI_PERF }; \
unsigned long cpu = smp_processor_id(); \
unsigned long flags; \
fn(&fn##_nb, (unsigned long)CPU_UP_PREPARE, \
(void *)(unsigned long)smp_processor_id()); \
(void *)(unsigned long)cpu); \
local_irq_save(flags); \
fn(&fn##_nb, (unsigned long)CPU_STARTING, \
(void *)(unsigned long)smp_processor_id()); \
(void *)(unsigned long)cpu); \
local_irq_restore(flags); \
fn(&fn##_nb, (unsigned long)CPU_ONLINE, \
(void *)(unsigned long)smp_processor_id()); \
(void *)(unsigned long)cpu); \
register_cpu_notifier(&fn##_nb); \
} while (0)