From: Alex Shi <alex.shi@intel.com>
To: Arjan van de Ven <arjan@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Morten Rasmussen <morten.rasmussen@arm.com>,
mingo@kernel.org, vincent.guittot@linaro.org,
preeti@linux.vnet.ibm.com, efault@gmx.de, pjt@google.com,
len.brown@intel.com, corbet@lwn.net, akpm@linux-foundation.org,
torvalds@linux-foundation.org, tglx@linutronix.de,
catalin.marinas@arm.com, linux-kernel@vger.kernel.org,
linaro-kernel@lists.linaro.org
Subject: Re: [RFC][PATCH 0/9] sched: Power scheduler design proposal
Date: Mon, 15 Jul 2013 10:05:15 +0800 [thread overview]
Message-ID: <51E358DB.4020705@intel.com> (raw)
In-Reply-To: <51E17CDD.30805@linux.intel.com>
On 07/14/2013 12:14 AM, Arjan van de Ven wrote:
>
>
> on thinking more about the short running task thing; there is an
> optimization we currently don't do,
> mostly for hyperthreading. (and HT is just one out of a set of cases
> with similar power behavior)
> If we know a task runs briefly AND is not performance critical, it's
> much much better to place it on
> a hyperthreading buddy of an already busy core than it is to place it on
> an empty core (or to delay it).
> Yes a HT pair isn't the same performance as a full core, but in terms of
> power the 2nd half of a HT pair
> is nearly free... so if there's a task that's not performance sensitive
> (and won't disturb the other task too much,
> e.g. runs briefly enough)... it's better to pack onto a core than to
> spread.
> you can generalize this to a class of systems where adding work to a
> core (read: group of cpus that share resources)
> is significantly cheaper than running on a full empty core.
Right!
That is one of purpose that my old power sheduling's wanna do:
https://lkml.org/lkml/2013/4/3/747
Vincent's patchset also target at this.
--
Thanks
Alex
next prev parent reply other threads:[~2013-07-15 2:06 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-09 15:55 [RFC][PATCH 0/9] sched: Power scheduler design proposal Morten Rasmussen
2013-07-09 15:55 ` [RFC][PATCH 1/9] sched: Introduce power scheduler Morten Rasmussen
2013-07-09 16:48 ` Arjan van de Ven
2013-07-10 2:10 ` Arjan van de Ven
2013-07-10 11:11 ` Morten Rasmussen
2013-07-10 11:19 ` Vincent Guittot
2013-07-09 15:55 ` [RFC][PATCH 2/9] sched: Redirect update_cpu_power to sched/power.c Morten Rasmussen
2013-07-09 15:55 ` [RFC][PATCH 3/9] sched: Make select_idle_sibling() skip cpu with a cpu_power of 1 Morten Rasmussen
2013-07-09 15:55 ` [RFC][PATCH 4/9] sched: Make periodic load-balance disregard cpus " Morten Rasmussen
2013-07-09 15:55 ` [RFC][PATCH 5/9] sched: Make idle_balance() skip " Morten Rasmussen
2013-07-09 15:55 ` [RFC][PATCH 6/9] sched: power: add power_domain data structure Morten Rasmussen
2013-07-09 15:55 ` [RFC][PATCH 7/9] sched: power: Add power driver interface Morten Rasmussen
2013-07-09 15:55 ` [RFC][PATCH 8/9] sched: power: Add initial frequency scaling support to power scheduler Morten Rasmussen
2013-07-10 13:10 ` Arjan van de Ven
2013-07-12 12:51 ` Morten Rasmussen
2013-07-12 13:06 ` Catalin Marinas
2013-07-12 15:37 ` Arjan van de Ven
2013-07-09 15:55 ` [RFC][PATCH 9/9] sched: power: cpufreq: Initial schedpower cpufreq governor Morten Rasmussen
2013-07-09 16:58 ` [RFC][PATCH 0/9] sched: Power scheduler design proposal Arjan van de Ven
2013-07-10 11:16 ` Morten Rasmussen
2013-07-10 13:05 ` Arjan van de Ven
2013-07-12 12:46 ` Morten Rasmussen
2013-07-12 15:35 ` Arjan van de Ven
2013-07-12 13:00 ` Catalin Marinas
2013-07-12 15:44 ` Arjan van de Ven
2013-07-11 11:34 ` Preeti U Murthy
2013-07-12 13:48 ` Morten Rasmussen
2013-07-15 3:43 ` Preeti U Murthy
2013-07-15 9:55 ` Catalin Marinas
2013-07-15 15:24 ` Arjan van de Ven
2013-07-12 13:31 ` Catalin Marinas
2013-07-13 6:49 ` Peter Zijlstra
2013-07-13 10:23 ` Catalin Marinas
2013-07-15 7:53 ` Vincent Guittot
2013-07-15 20:39 ` Peter Zijlstra
2013-07-16 12:42 ` Catalin Marinas
2013-07-16 15:23 ` Arjan van de Ven
2013-07-17 14:14 ` Catalin Marinas
2013-07-24 13:50 ` Morten Rasmussen
2013-07-24 15:16 ` Arjan van de Ven
2013-07-24 16:46 ` Morten Rasmussen
2013-07-24 16:48 ` Arjan van de Ven
2013-07-25 8:00 ` Morten Rasmussen
2013-07-13 14:40 ` Arjan van de Ven
2013-07-15 19:59 ` Peter Zijlstra
2013-07-15 20:37 ` Arjan van de Ven
2013-07-15 21:03 ` Peter Zijlstra
2013-07-15 22:46 ` Arjan van de Ven
2013-07-16 20:45 ` David Lang
2013-07-15 20:41 ` Arjan van de Ven
2013-07-15 21:06 ` Peter Zijlstra
2013-07-15 21:12 ` Peter Zijlstra
2013-07-15 22:52 ` Arjan van de Ven
2013-07-16 17:38 ` Peter Zijlstra
2013-07-16 18:44 ` Arjan van de Ven
2013-07-16 19:21 ` Peter Zijlstra
2013-07-16 19:57 ` Arjan van de Ven
2013-07-16 20:17 ` Peter Zijlstra
2013-07-16 20:21 ` Arjan van de Ven
2013-07-16 20:32 ` Arjan van de Ven
2013-07-15 22:46 ` Arjan van de Ven
2013-07-13 16:14 ` Arjan van de Ven
2013-07-15 2:05 ` Alex Shi [this message]
2013-07-24 13:16 ` Morten Rasmussen
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