From: Andre Heider <a.heider@gmail.com>
To: "Marek Behún" <kabel@kernel.org>, arm@kernel.org
Cc: "Tomasz Maciej Nowak" <tmn505@gmail.com>,
"Luka Perkov" <luka.perkov@sartura.hr>,
"Gregory CLEMENT" <gregory.clement@bootlin.com>,
soc@kernel.org, "Vladimir Vid" <vladimir.vid@sartura.hr>,
"Russell King" <rmk+kernel@armlinux.org.uk>,
"Gérald Kerma" <gerald@gk2.net>,
"Miquel Raynal" <miquel.raynal@bootlin.com>,
"Konstantin Porotchkin" <kostap@marvell.com>,
pali@kernel.org, linux-arm-kernel@lists.infradead.org
Subject: Re: Armada 3720 cpufreq bug: request for testing (EspressoBIN, uDPU, ...)
Date: Mon, 12 Oct 2020 07:19:48 +0200 [thread overview]
Message-ID: <d4064524-d59d-15dc-a373-2d1473151b8b@gmail.com> (raw)
In-Reply-To: <20201009125711.0176752a@kernel.org>
Hi Marek,
On 09/10/2020 12:57, Marek Behún wrote:
> I have a request for testing some patches that fix cpufreq issues on
> Armada 3720 (EspressoBIN, uDPU, Devel Board, maybe others?).
>
> It concerns top 4 commits of branch a3720-cpufreq-issues of repository
> https://git.kernel.org/pub/scm/linux/kernel/git/kabel/linux.git/
>
> (log at https://git.kernel.org/pub/scm/linux/kernel/git/kabel/linux.git/log/?h=a3720-cpufreq-issues)
>
> We've discovered a bug in Armada 3720 cpufreq driver that causes
> base CPU frequency to drop to 800 MHz on systems configured to 1 GHz.
> More info here:
> https://www.spinics.net/lists/arm-kernel/msg844752.html
>
> The patchset above led us to discover another bug, in the SOC itself,
> that causes the CPU to behave weirdly when frequency changes to 1 GHz.
> A similar erratum is documented by Marvell but only for systems where
> base frequency is 1.2 GHz.
>
> We've discovered that to make cpufreq scaling stable on Armada 3720
> on systems with base frequency 1 GHz, we also have to set voltage levels
> for L1, L2 and L3 loads to 1108 mV. (We were led to this by patch we found here
> https://forum.armbian.com/topic/10429-how-to-make-espressobin-v7-stable/page/2/?tab=comments#comment-80012).
>
> We would like you to build this sources and test the ondemand cpufreq
> governor on systems with variable CPU load, for at least 1 day (more is better).
> If you could also test the userspace governor and randomly change frequency,
> it would be great.
>
> Please let me know if and when you are willing to do this.
Thanks for hunting this one down!
I've applied your 4 patches to v5.9 and gave it a quick spin.
I'm using schedutil, which had the very same issue. It never actually
switched to 1000mhz. It claimed it did, but the `mhz` util as well as
the 7z benchmark proved it never used anything >800mhz.
Before:
$ 7z b
7-Zip [64] 16.02 : Copyright (c) 1999-2016 Igor Pavlov : 2016-05-21
p7zip Version 16.02 (locale=en_US.UTF-8,Utf16=on,HugeFiles=on,64 bits,2
CPUs LE)
LE
CPU Freq: 793 793 794 793 794 792 793 794
RAM size: 985 MB, # CPU hardware threads: 2
RAM usage: 441 MB, # Benchmark threads: 2
Compressing | Decompressing
Dict Speed Usage R/U Rating | Speed Usage R/U Rating
KiB/s % MIPS MIPS | KiB/s % MIPS MIPS
22: 711 149 464 692 | 17501 194 770 1494
23: 708 155 465 722 | 17595 198 770 1523
24: 682 158 464 734 | 17079 196 764 1499
25: 663 160 473 757 | 15595 189 734 1388
---------------------------------- | ------------------------------
Avr: 156 466 726 | 194 760 1476
Tot: 175 613 1101
After:
$ 7z b
7-Zip [64] 16.02 : Copyright (c) 1999-2016 Igor Pavlov : 2016-05-21
p7zip Version 16.02 (locale=en_US.UTF-8,Utf16=on,HugeFiles=on,64 bits,2
CPUs LE)
LE
CPU Freq: 992 998 998 994 996 997 997 997
RAM size: 987 MB, # CPU hardware threads: 2
RAM usage: 441 MB, # Benchmark threads: 2
Compressing | Decompressing
Dict Speed Usage R/U Rating | Speed Usage R/U Rating
KiB/s % MIPS MIPS | KiB/s % MIPS MIPS
22: 866 151 559 843 | 22334 198 962 1907
23: 872 152 584 889 | 21809 197 959 1888
24: 808 145 599 869 | 11413 110 915 1002
25: 716 137 596 819 | 21092 198 949 1877
---------------------------------- | ------------------------------
Avr: 146 585 855 | 176 946 1669
Tot: 161 765 1262
The measured frequency as well as the performance data finally looks
good, so:
Tested-by: Andre Heider <a.heider@gmail.com>
Thanks,
Andre
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next prev parent reply other threads:[~2020-10-12 5:21 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-09 10:57 Armada 3720 cpufreq bug: request for testing (EspressoBIN, uDPU, ...) Marek Behún
2020-10-12 5:19 ` Andre Heider [this message]
2020-10-26 14:54 ` Pali Rohár
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