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authorSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>2012-10-16 13:28:17 +0530
committerIngo Molnar <mingo@kernel.org>2012-10-24 10:01:59 +0200
commitc13d38e4a1fd5dd07135403c613c8091af444169 (patch)
tree85bdc667286f9c9d4437c2020f2dd0d60a8f2c89 /include/linux/perf_event.h
parent6760bca9fd16256210f4922a3e9f067d2c7017d7 (diff)
downloadop-kernel-dev-c13d38e4a1fd5dd07135403c613c8091af444169.zip
op-kernel-dev-c13d38e4a1fd5dd07135403c613c8091af444169.tar.gz
perf, cpu hotplug: Use cached value of smp_processor_id()
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>
Diffstat (limited to 'include/linux/perf_event.h')
-rw-r--r--include/linux/perf_event.h7
1 files changed, 4 insertions, 3 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 0647805..6bfb2faa 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -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)
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