From: Peter Zijlstra <peterz@infradead.org>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: mingo@kernel.org, linux-kernel@vger.kernel.org, kernellwp@gmail.com
Subject: Re: [PATCH] sched/schedutil : optimize utilization scaling for guest kernel
Date: Wed, 29 Aug 2018 14:45:03 +0200 [thread overview]
Message-ID: <20180829124503.GU24124@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <1535532702-3508-1-git-send-email-vincent.guittot@linaro.org>
On Wed, Aug 29, 2018 at 10:51:42AM +0200, Vincent Guittot wrote:
> Scaling the utilization of CPUs with irq util_avg in schedutil doesn't give
> any benefit and just waste CPU cycles when irq time is not accounted but
> only steal time.
> Add an internal _scale_irq_capacity() for scale_rt_capacity but scale
> cpu utilization in schedutil only if we are accounting irq time.
This makes a mess of things; also it doesn't really do what it says.
Even if we have CONFIG_IRQ_TIME_ACCOUNTING, that doesn't mean we do it,
just that it is capable.
next prev parent reply other threads:[~2018-08-29 12:45 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-29 8:51 Vincent Guittot
2018-08-29 12:45 ` Peter Zijlstra [this message]
2018-08-29 14:06 ` Vincent Guittot
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