From: tglx@linutronix.de (Thomas Gleixner)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 7/7] ARM: smp: Add runtime PM support for CPU hotplug
Date: Tue, 22 Sep 2015 22:53:14 +0200 (CEST) [thread overview]
Message-ID: <alpine.DEB.2.11.1509222251070.5606@nanos> (raw)
In-Reply-To: <20150922173236.GB19183@linaro.org>
On Tue, 22 Sep 2015, Lina Iyer wrote:
> Talking to John Stultz at Linaro Connect: Is cpuidle relevant in
> -RT kernel? I dont know much about -RT. I thought this might be point
> that we should consider.
There are definitely RT systems out there where power consumption is a
concern.
> As it stands today, on a 800 Mhz ARM quad core, I am seeing a latency of
> 50-70 usec for the additional runtime PM in the cpuidle. Ofcourse, there
> is a definite need to optimize and there are opportunities to do that.
RT is not about being fast. RT is about being deterministic. So if a
power sensitive RT system can afford the extra latencies induced by PM
it will tolerate them. Of course, optimizing that is not a bad thing
at all :)
Thanks,
tglx
prev parent reply other threads:[~2015-09-22 20:53 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-03 19:58 [PATCH v2 0/7] PM / Domains: Generic PM domains for CPUs/Clusters Lina Iyer
2015-09-03 19:58 ` [PATCH v2 1/7] PM / Domains: Allocate memory outside domain locks Lina Iyer
2015-09-03 19:58 ` [PATCH v2 2/7] PM / Domains: Support IRQ safe PM domains Lina Iyer
2015-09-04 10:02 ` Ulf Hansson
2015-09-04 16:05 ` Lina Iyer
2015-10-01 21:11 ` Geert Uytterhoeven
2015-09-03 19:58 ` [PATCH v2 3/7] drivers: cpu: Define CPU devices as IRQ safe Lina Iyer
2015-09-04 4:00 ` Stephen Boyd
2015-09-03 19:58 ` [PATCH v2 4/7] PM / Domains: Introduce PM domains for CPUs/clusters Lina Iyer
2015-09-04 3:54 ` Stephen Boyd
2015-09-03 19:58 ` [PATCH v2 5/7] ARM: cpuidle: Add runtime PM support for CPU idle Lina Iyer
2015-09-03 19:58 ` [PATCH v2 6/7] ARM64: smp: Add runtime PM support for CPU hotplug Lina Iyer
2015-09-30 12:36 ` Geert Uytterhoeven
2015-09-03 19:58 ` [PATCH v2 7/7] ARM: " Lina Iyer
2015-09-04 3:59 ` Stephen Boyd
2015-09-04 15:13 ` Lina Iyer
2015-09-04 7:39 ` Geert Uytterhoeven
2015-09-04 9:17 ` Russell King - ARM Linux
2015-09-04 9:27 ` Russell King - ARM Linux
2015-09-04 15:12 ` Lina Iyer
2015-09-04 16:23 ` Russell King - ARM Linux
2015-09-04 17:02 ` Lina Iyer
2015-09-04 17:46 ` Russell King - ARM Linux
2015-09-04 17:57 ` Grygorii Strashko
2015-09-04 18:45 ` Alan Stern
2015-09-04 21:46 ` Grygorii Strashko
2015-09-05 15:39 ` Alan Stern
2015-09-07 13:04 ` Rafael J. Wysocki
2015-09-07 13:37 ` Grygorii Strashko
2015-09-07 20:42 ` Rafael J. Wysocki
2015-09-08 8:21 ` Grygorii Strashko
2015-09-08 22:03 ` Kevin Hilman
2015-09-10 11:01 ` Grygorii Strashko
2015-09-22 17:32 ` Lina Iyer
2015-09-22 20:53 ` Thomas Gleixner [this message]
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