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Subject: Re: [PATCH] perf_event: fix slow and broken cgroup context switch
 code
From: Peter Zijlstra <peterz@infradead.org>
To: Stephane Eranian <eranian@google.com>
Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, ming.m.lin@intel.com
Date: Thu, 25 Aug 2011 16:22:28 +0200
In-Reply-To: <20110825135803.GA4697@quad>
References: <20110825135803.GA4697@quad>
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On Thu, 2011-08-25 at 15:58 +0200, Stephane Eranian wrote:
> +static inline void perf_event_task_sched_in(struct task_struct *prev,
> +                                           struct task_struct *task)
>  {
>         if (static_branch(&perf_sched_events))
> +               __perf_event_task_sched_in(prev, task);
>  }
>  
> +static inline void perf_event_task_sched_out(struct task_struct *prev,
> +                                            struct task_struct *next)
>  {
>         perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, NULL, 0);
>  
> +       if (static_branch(&perf_sched_events))
> +               __perf_event_task_sched_out(prev, next);
>  }

BTW, Ingo, is there any particular reason we have these two calls and
not a single perf_event_task_switch() call?