From: Mike Galbraith <efault@gmx.de>
To: Shaohua Li <shaohua.li@intel.com>
Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, zheng.z.yan@intel.com
Subject: Re: [PATCH]sched: convert wall-time to vruntime for check_preempt_tick
Date: Thu, 07 Apr 2011 15:34:20 +0200 [thread overview]
Message-ID: <1302183260.8065.9.camel@marge.simson.net> (raw)
In-Reply-To: <20110407124332.GA31809@sli10-conroe.sh.intel.com>
On Thu, 2011-04-07 at 20:43 +0800, Shaohua Li wrote:
> In check_preempt_tick(), delta is vruntime and ideal_runtime is wall runtime.
> Comparing vruntime and ideal_runtime looks buggy.
Why is that buggy? It's a distance in units ns, ala wakeup_granularity,
a number. This number just happens to be variable.
> Signed-off-by: Shaohua Li <shaohua.li@intel.com>
>
> diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
> index 3f7ec9e..0b76e3a 100644
> --- a/kernel/sched_fair.c
> +++ b/kernel/sched_fair.c
> @@ -1121,7 +1121,7 @@ check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
> if (delta < 0)
> return;
>
> - if (delta > ideal_runtime)
> + if (delta > calc_delta_fair(ideal_runtime, curr))
> resched_task(rq_of(cfs_rq)->curr);
> }
> }
> --
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next prev parent reply other threads:[~2011-04-07 13:34 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-07 12:43 [PATCH]sched: convert wall-time to vruntime for check_preempt_tick Shaohua Li
2011-04-07 13:34 ` Mike Galbraith [this message]
2011-04-08 0:35 ` Shaohua Li
2011-04-08 2:49 ` Mike Galbraith
2011-04-08 4:55 ` Shaohua Li
2011-04-08 5:31 ` Mike Galbraith
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