From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC] Fixing CPU Hotplug for RealView Platforms
Date: Mon, 3 Jan 2011 10:46:21 +0000 [thread overview]
Message-ID: <20110103104621.GF26785@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <AANLkTinMobeQBz_ruGAeOSoTWP_9-0Aw4-=8Sk3JxEjX@mail.gmail.com>
On Mon, Dec 20, 2010 at 09:16:15AM +0100, Vincent Guittot wrote:
> I'm also interested in hotplug latency measurement and have done some
> on my CA9 platform u8500. I have the same kind of result for plugging
> a secondary cpu:
> total duration = 295ms
> 166 us for the low level cpu wake up
> 228ms between the return from platform_cpu_die and the cpu becomes online
>
> I have added some trace events for doing these measurements and I'd
> like to add some generic traces point in the cpu hotplug code like we
> already have in power management code (cpuidle, suspend, cpufreq ...)
> These traces could be used with power events for studying the impact
> of cpu hotplug in the complete power management scheme.
Note that if you pass lpj=<number> to the kernel, you'll bypass the
calibration and have a faster response to CPU onlining.
next prev parent reply other threads:[~2011-01-03 10:46 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-20 8:16 [RFC] Fixing CPU Hotplug for RealView Platforms Vincent Guittot
2011-01-03 10:46 ` Russell King - ARM Linux [this message]
2011-01-03 17:39 ` Vincent Guittot
2011-01-03 18:03 ` Russell King - ARM Linux
2011-01-04 8:55 ` Vincent Guittot
-- strict thread matches above, loose matches on Subject: below --
2010-12-07 16:43 Will Deacon
2010-12-07 17:18 ` Russell King - ARM Linux
2010-12-07 17:47 ` Will Deacon
2010-12-08 6:03 ` Santosh Shilimkar
2010-12-08 13:20 ` Will Deacon
2010-12-08 20:20 ` Russell King - ARM Linux
2010-12-18 17:10 ` Russell King - ARM Linux
2010-12-18 17:44 ` Will Deacon
2010-12-18 19:22 ` Russell King - ARM Linux
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