Re: [GIT PULL rcu/next] RCU commits for 3.1

["Paul E. McKenney" <paulmck@linux.vnet.ibm.com>]

On Mon, Nov 07, 2011 at 06:09:49PM +0100, Peter Zijlstra wrote:
> On Mon, 2011-11-07 at 08:56 -0800, Paul E. McKenney wrote:
> > 
> > If this really is a false positive, what should be used to get rid of
> > the splats? 
> 
> 
> Probably something slightly less horrid than the below.. ;-)

Hmmm...  Could the "1" below be replaced by the task's reference count?
Probabilistic, but should eventually catch it.

							Thanx, Paul

> ---
> 
> diff --git a/kernel/events/core.c b/kernel/events/core.c
> index d1a1bee..8f05201 100644
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -229,7 +229,7 @@ static void perf_ctx_unlock(struct perf_cpu_context *cpuctx,
>  static inline struct perf_cgroup *
>  perf_cgroup_from_task(struct task_struct *task)
>  {
> -	return container_of(task_subsys_state(task, perf_subsys_id),
> +	return container_of(task_subsys_state_check(task, perf_subsys_id, 1),
>  			struct perf_cgroup, css);
>  }
>  
>