From: Srivatsa S. Bhat Date: Tue, 16 Oct 2012 07:58:17 +0000 (+0530) Subject: perf, cpu hotplug: Use cached value of smp_processor_id() X-Git-Tag: v3.7-rc3~20^2~8 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c13d38e4a1fd5dd07135403c613c8091af444169;p=platform%2Fupstream%2Fkernel-adaptation-pc.git 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 Reviewed-by: Paul E. McKenney 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 --- 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)