From: Daniel Lezcano <daniel.lezcano@linaro.org>
To: Vincent Guittot <vincent.guittot@linaro.org>,
xuwei5@hisilicon.com, robh+dt@kernel.org,
linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org
Cc: leo.yan@linaro.org
Subject: Re: [PATCH] arm64: hikey960: update idle-states
Date: Fri, 6 Jul 2018 09:59:15 +0200 [thread overview]
Message-ID: <722aed2b-673b-7f17-2337-a7b3442dca56@linaro.org> (raw)
In-Reply-To: <1530860246-29072-1-git-send-email-vincent.guittot@linaro.org>
On 06/07/2018 08:57, Vincent Guittot wrote:
> Update entry/exit latency and residency time of hikey960 to use more
> realistic figures based on unitary tests done on the platform.
>
> The complete results (in us) :
> big cluster
> cluster CPU
> max entry latency 800 400
> max exit latency 2900 550
> residency 903Mhz 5000 1500
> residency 2363Mhz 0 1500
>
> little cluster
> cluster CPU
> max entry latency 500 400
> max exit latency 1600 650
> residency 533Mhz 8000 4500
> residency 1844Mhz 0 1500
>
> We can see that the residency time depends of the running OPP which is not
> handled for now. Then we also have to take into account the constraint of
> a residency time shorter than the tick to get full advantage of idle loop
> reordering(tick is stopped if idle duration is higher than tick period).
> Finally the selected residency value are :
> big cluster
> cluster CPU
> residency 3700 1500
>
> little cluster
> cluster CPU
> residency 3500 1500
>
> A simple test with a task waking up every 11,111ms shows improvement:
> - 5% a lowest OPP
> - 22% at highest OPP
>
> The period has been chosen:
> - to be shorter than old cluster residency time and longer than new
> residency time od cluster off C-state
> - to prevent any sync with tick (4ms) when running tests that can add
> some variances between tests
>
> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
> ---
Great! Thanks for fixing the values.
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
--
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog
next prev parent reply other threads:[~2018-07-06 7:59 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-06 6:57 [PATCH] arm64: hikey960: update idle-states Vincent Guittot
2018-07-06 7:59 ` Daniel Lezcano [this message]
2018-07-08 14:01 ` leo.yan
2018-07-08 21:15 ` Daniel Lezcano
2018-07-08 23:26 ` leo.yan
2018-07-11 8:27 ` Vincent Guittot
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=722aed2b-673b-7f17-2337-a7b3442dca56@linaro.org \
--to=daniel.lezcano@linaro.org \
--cc=devicetree@vger.kernel.org \
--cc=leo.yan@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=robh+dt@kernel.org \
--cc=vincent.guittot@linaro.org \
--cc=xuwei5@hisilicon.com \
/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;
as well as URLs for NNTP newsgroup(s).