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Subject: Re: [tg_shares_up rewrite v3 09/11] sched: demand based
 update_cfs_load()
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Paul Turner <pjt@google.com>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@elte.hu>,
        Srivatsa Vaddagiri <vatsa@in.ibm.com>,
        Chris Friesen <cfriesen@nortel.com>,
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        Pierre Bourdon <pbourdon@excellency.fr>,
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	 <20101112032702.028843817@google.com>
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Date: Fri, 12 Nov 2010 11:53:18 +0100
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On Thu, 2010-11-11 at 19:24 -0800, Paul Turner wrote:
> +#ifdef CONFIG_FAIR_GROUP_SCHED
> +       cfs_rq->load_unacc_exec_time += delta_exec;
> +       if (cfs_rq->load_unacc_exec_time > sysctl_sched_shares_window)
> {
> +               update_cfs_load(cfs_rq);
> +               update_cfs_shares(cfs_rq, 0);

Why not:
+		cfs_rq->load_unacc_exec_time -= sysctl_sched_shares_window;

(although you probably want to read the sysctl value into a local
variable using ACCESS_ONCE() and use that for both cases).

> +       }
> +#endif
>  }
>  
>  static void update_curr(struct cfs_rq *cfs_rq)
> @@ -713,6 +724,7 @@ static void update_cfs_load(struct cfs_r
>         }
>  
>         cfs_rq->load_stamp = now;
> +       cfs_rq->load_unacc_exec_time = 0; 

and drop this one?