From: Thomas Gleixner <tglx@linutronix.de>
To: Lina Iyer <lina.iyer@linaro.org>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>,
Kevin Hilman <khilman@kernel.org>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Alan Stern <stern@rowland.harvard.edu>,
Russell King - ARM Linux <linux@arm.linux.org.uk>,
Mark Rutland <mark.rutland@arm.com>,
ulf.hansson@linaro.org,
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
linux-pm@vger.kernel.org,
Catalin Marinas <catalin.marinas@arm.com>,
k.kozlowski@samsung.com, msivasub@codeaurora.org,
geert@linux-m68k.org, agross@codeaurora.org,
sboyd@codeaurora.org, linux-arm-kernel@lists.infradead.org,
Ingo Molnar <mingo@kernel.org>,
john.stultz@linaro.org
Subject: Re: [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]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=alpine.DEB.2.11.1509222251070.5606@nanos \
--to=tglx@linutronix.de \
--cc=agross@codeaurora.org \
--cc=catalin.marinas@arm.com \
--cc=geert@linux-m68k.org \
--cc=grygorii.strashko@ti.com \
--cc=john.stultz@linaro.org \
--cc=k.kozlowski@samsung.com \
--cc=khilman@kernel.org \
--cc=lina.iyer@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-pm@vger.kernel.org \
--cc=linux@arm.linux.org.uk \
--cc=lorenzo.pieralisi@arm.com \
--cc=mark.rutland@arm.com \
--cc=mingo@kernel.org \
--cc=msivasub@codeaurora.org \
--cc=rjw@rjwysocki.net \
--cc=sboyd@codeaurora.org \
--cc=stern@rowland.harvard.edu \
--cc=ulf.hansson@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox