Messages in this thread Patch in this message | | | From | "Srivatsa S. Bhat" <> | Subject | [PATCH 2/2] perf, cpu hotplug: Use cached value of smp_processor_id() | Date | Thu, 13 Sep 2012 20:12:26 +0530 |
| |
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> ---
include/linux/perf_event.h | 7 ++++--- 1 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index cc4574d..5b5b017 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1346,15 +1346,16 @@ 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)
| |