From: Arjan van de Ven <arjan@infradead.org>
To: Pavel Machek <pavel@ucw.cz>
Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
mingo@elte.hu, peterz@infradead.org, tglx@linutronix.de,
davej@redhat.com, cpufreq@vger.kernel.org
Subject: Re: [PATCH 7/7] ondemand: Solve the big performance issue with ondemand during disk IO
Date: Fri, 23 Apr 2010 06:52:48 -0700 [thread overview]
Message-ID: <20100423065248.3b0a98ab@infradead.org> (raw)
In-Reply-To: <20100423052439.GB4829@ucw.cz>
On Fri, 23 Apr 2010 07:24:39 +0200
Pavel Machek <pavel@ucw.cz> wrote:
>
> Well, and now, if you do something like cat /dev/<your usb1.1 hdd> >
> /dev/null, you'll keep cpu on max frequency. Not a problem for new
> core i7, but probably big deal for athlon 64.
do you have facts not speculation for this? Does the athlon 64 really
keep its voltage high during idle? That would surprise me greatly...
(and if it does, does it matter? the clock is stopped anyway there)
the only place where my patch makes a real difference is when the cpu
is idle due to blocking IO! So do you have data that the athlon 64 gets
too hot if you select a high frequency during an idle period, where the
clock is already stopped?
--
Arjan van de Ven Intel Open Source Technology Centre
For development, discussion and tips for power savings,
visit http://www.lesswatts.org
next prev parent reply other threads:[~2010-04-23 13:51 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-18 18:59 [PATCH 0/7] Fix performance issue with ondemand governor Arjan van de Ven
2010-04-18 19:00 ` [PATCH 1/7] sched: add a comment to get_cpu_idle_time_us() Arjan van de Ven
2010-04-26 19:25 ` Rik van Riel
2010-04-18 19:01 ` [PATCH 2/7] sched: introduce a function to update the idle statistics Arjan van de Ven
2010-04-26 20:11 ` Rik van Riel
2010-04-18 19:01 ` [PATCH 3/7] sched: update the idle statistics in get_cpu_idle_time_us() Arjan van de Ven
2010-04-26 20:36 ` Rik van Riel
2010-04-18 19:02 ` [PATCH 4/7] sched: fold updating of the last update time into update_ts_time_stats() Arjan van de Ven
2010-04-26 20:58 ` Rik van Riel
2010-04-18 19:02 ` [PATCH 5/7] sched: eliminate the ts->idle_lastupdate field Arjan van de Ven
2010-04-26 21:00 ` Rik van Riel
2010-04-18 19:03 ` [PATCH 6/7] sched: introduce get_cpu_iowait_time_us() Arjan van de Ven
2010-04-26 21:05 ` Rik van Riel
2010-04-18 19:03 ` [PATCH 7/7] ondemand: Solve the big performance issue with ondemand during disk IO Arjan van de Ven
2010-04-19 8:29 ` Éric Piel
2010-04-19 13:43 ` Arjan van de Ven
2010-04-19 14:30 ` Éric Piel
2010-04-19 14:47 ` Arjan van de Ven
2010-04-20 9:24 ` Thomas Renninger
2010-04-27 0:29 ` Mike Chan
2010-04-27 13:01 ` Pavel Machek
2010-04-27 18:10 ` Mike Chan
2010-04-19 9:09 ` Tvrtko Ursulin
2010-04-19 13:46 ` Arjan van de Ven
2010-04-19 15:29 ` Tvrtko Ursulin
2010-04-20 0:47 ` Arjan van de Ven
2010-04-20 9:10 ` Tvrtko Ursulin
2010-04-20 11:02 ` Arjan van de Ven
2010-04-28 8:57 ` Tvrtko Ursulin
2010-04-23 5:26 ` Pavel Machek
2010-04-20 9:29 ` Thomas Renninger
2010-04-20 11:07 ` Arjan van de Ven
2010-04-23 5:24 ` Pavel Machek
2010-04-23 5:38 ` Willy Tarreau
2010-04-23 8:50 ` Thomas Renninger
2010-04-23 16:08 ` Arjan van de Ven
2010-04-27 11:39 ` Thomas Renninger
2010-05-04 3:48 ` [PATCH 8/7] cpufreq: make the iowait-is-busy-time a sysfs tunable Arjan van de Ven
2010-05-04 4:16 ` Willy Tarreau
2010-05-04 5:43 ` Pavel Machek
2010-05-04 13:51 ` Rik van Riel
2010-04-23 14:10 ` [PATCH 7/7] ondemand: Solve the big performance issue with ondemand during disk IO Arjan van de Ven
2010-04-23 15:35 ` Willy Tarreau
2010-04-23 13:52 ` Arjan van de Ven [this message]
2010-04-23 8:38 ` Pavel Machek
2010-04-23 16:06 ` Arjan van de Ven
2010-04-24 4:56 ` Pavel Machek
2010-05-01 23:29 ` Arjan van de Ven
2010-04-26 21:30 ` Rik van Riel
2010-04-26 21:41 ` [PATCH 0/7] Fix performance issue with ondemand governor Dave Jones
2010-04-26 21:45 ` Dominik Brodowski
2010-04-26 21:59 ` Rik van Riel
2010-04-26 22:05 ` Dominik Brodowski
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