On Tue, Oct 16, 2012 at 01:28:17PM +0530, Srivatsa S. Bhat wrote:
> 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.b...@linux.vnet.ibm.com>
Reviewed-by: Paul E. McKenney <paul...@linux.vnet.ibm.com>
> ---
>
> include/linux/perf_event.h | 7 ++++---
> 1 file 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)
>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
