Re: [RFC][PATCH 4/5] sched: Clean up ttwu stats

[Frank Rowand <frank.rowand@am.sony.com>]

On 12/16/10 06:56, Peter Zijlstra wrote:
> Collect all ttwu stat code into a single function and ensure its
> always called for an actual wakeup (changing p->state to
> TASK_RUNNING).
> 
> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
> ---
>  kernel/sched.c |   66 ++++++++++++++++++++++++++-------------------------------
>  1 file changed, 31 insertions(+), 35 deletions(-)

Looks good to me.  Nice cleanup...

A couple of nits inline if you want them.

Acked-by: Frank Rowand <frank.rowand@am.sony.com>

> 
> Index: linux-2.6/kernel/sched.c
> ===================================================================
> --- linux-2.6.orig/kernel/sched.c
> +++ linux-2.6/kernel/sched.c
> @@ -2310,21 +2310,35 @@ static void update_avg(u64 *avg, u64 sam
>  }
>  #endif
>  
> -static inline void ttwu_activate(struct task_struct *p, struct rq *rq,
> -				 bool is_sync, bool is_migrate, bool is_local,
> -				 unsigned long en_flags)
> +static void
> +ttwu_stat(struct rq *rq, struct task_struct *p, int cpu, int wake_flags)
>  {
> +#ifdef CONFIG_SCHEDSTATS
> +

        int this_cpu = smp_processor_id();

> +	schedstat_inc(rq, ttwu_count);
>  	schedstat_inc(p, se.statistics.nr_wakeups);
> -	if (is_sync)
> +
> +	if (wake_flags & WF_SYNC)
>  		schedstat_inc(p, se.statistics.nr_wakeups_sync);
> -	if (is_migrate)
> +
> +	if (cpu != task_cpu(p))
>  		schedstat_inc(p, se.statistics.nr_wakeups_migrate);
> -	if (is_local)
> +
> +	if (cpu == smp_processor_id()) {

                    ^^^^^^  this_cpu

> +		schedstat_inc(rq, ttwu_local);
>  		schedstat_inc(p, se.statistics.nr_wakeups_local);
> -	else
> -		schedstat_inc(p, se.statistics.nr_wakeups_remote);
> +	} else {
> +		struct sched_domain *sd;
>  
> -	activate_task(rq, p, en_flags);
> +		schedstat_inc(p, se.statistics.nr_wakeups_remote);
> +		for_each_domain(smp_processor_id(), sd) {

                                ^^^^^ this_cpu

> +			if (cpumask_test_cpu(cpu, sched_domain_span(sd))) {
> +				schedstat_inc(sd, ttwu_wake_remote);
> +				break;
> +			}
> +		}
> +	}
> +#endif /* CONFIG_SCHEDSTATS */
>  }
>  
>  static void