Re: [PATCH] perf_counter: cleanup for __perf_event_sched_in()

[Peter Zijlstra <peterz@infradead.org>]

On Tue, 2009-09-22 at 16:47 +0800, Xiao Guangrong wrote:
> It must be a group leader if event->attr.pinned is "1"

Since we already enforce that on counter creation, this seems OK.

Thanks

> Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
> ---
>  kernel/perf_event.c |   11 +++++------
>  1 files changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/kernel/perf_event.c b/kernel/perf_event.c
> index 76ac4db..fdd9c94 100644
> --- a/kernel/perf_event.c
> +++ b/kernel/perf_event.c
> @@ -1258,12 +1258,11 @@ __perf_event_sched_in(struct perf_event_context *ctx,
>  		if (event->cpu != -1 && event->cpu != cpu)
>  			continue;
>  
> -		if (event != event->group_leader)
> -			event_sched_in(event, cpuctx, ctx, cpu);
> -		else {
> -			if (group_can_go_on(event, cpuctx, 1))
> -				group_sched_in(event, cpuctx, ctx, cpu);
> -		}
> +		/* Only a group leader can be pinned */
> +		BUG_ON(event != event->group_leader);
> +
> +		if (group_can_go_on(event, cpuctx, 1))
> +			group_sched_in(event, cpuctx, ctx, cpu);
>  
>  		/*
>  		 * If this pinned group hasn't been scheduled,