[fedora-arm] Re: Fedora 24 Mate Spin fails to start all cpus on Odroid-Xu4

Post by Stewart Samuels
Hi Peter,
Here is the result of lscpu.
---------------------------------------------------------------------------------------
Architecture: armv7l
Byte Order: Little Endian
CPU(s): 8
On-line CPU(s) list: 0-4
Off-line CPU(s) list: 5-7
Thread(s) per core: 1
Core(s) per socket: 2
Socket(s): 2
Model name: ARMv7 Processor rev 3 (v7l)
CPU max MHz: 1300.0000
CPU min MHz: 200.0000
----------------------------------------------------------------------------------------
Is there any way to enable these other cpus? My Ubuntu 16.04 installation
has them all enabled and the Ubuntu responsiveness is much quicker. I
suspect this has something to do with it.

So it's shut them off, it's something with the way the big.LITTLE
stuff works, so it's basically as expected. I believe it's handled as
part of the cpufreq policies from user space but I've done little with
the b.L stuff so I'm not sure. I'd try with the performance policy
first.

In terms of speed vs other distros, it would likely depend on a lot
more than just the cores that are running but I have no idea what
you're doing with it (remote server/desktop/what ever) so there's
likely a lot that will come into play.

Stewart Samuels

2016-09-08 12:19:53 UTC

Hi Peter,

I am not doing anything with the system other than booting up and
logging in. This is true for the Ubuntu build as well.

Where are these policies set and can you provide any me any direction
for documentation on them? seeming these are distro specific, I would
expect something relative to Fedora.

Thanks.

Stewart

So it's shut them off, it's something with the way the big.LITTLE
stuff works, so it's basically as expected. I believe it's handled as
part of the cpufreq policies from user space but I've done little with
the b.L stuff so I'm not sure. I'd try with the performance policy
first.
In terms of speed vs other distros, it would likely depend on a lot
more than just the cores that are running but I have no idea what
you're doing with it (remote server/desktop/what ever) so there's
likely a lot that will come into play.

Peter Robinson

2016-09-08 12:40:02 UTC

Post by Stewart Samuels
Hi Peter,
I am not doing anything with the system other than booting up and logging
in. This is true for the Ubuntu build as well.
Where are these policies set and can you provide any me any direction for
documentation on them? seeming these are distro specific, I would expect
something relative to Fedora.

Nope, they are upstream kernel (and possibly even upstream u-boot)
specific. The only default we set in this regard that may, or may not,
be Fedora specific is we use the On Demand governor as the default.
This is architecture in dependent default across Fedora.

I doubt the Ubuntu build ships an upstream mainline kernel but then I
don't follow any of what they do so TBH not sure there, I also have no
idea what they set their default policy to.

So doing a quick google for "cpufreq" I get some of the following
links that look remotely relevant, no idea how much they are, sorry.

https://docs.fedoraproject.org/en-US/Fedora/15/html/Power_Management_Guide/cpufreq_governors.html
https://wiki.archlinux.org/index.php/CPU_frequency_scaling
https://www.kernel.org/doc/Documentation/cpu-freq/governors.txt
https://www.pantz.org/software/cpufreq/usingcpufreqonlinux.html
http://www.ibm.com/developerworks/library/l-cpufreq-1/index.html
https://wiki.debian.org/HowTo/CpuFrequencyScaling

So it's shut them off, it's something with the way the big.LITTLE
stuff works, so it's basically as expected. I believe it's handled as
part of the cpufreq policies from user space but I've done little with
the b.L stuff so I'm not sure. I'd try with the performance policy
first.
In terms of speed vs other distros, it would likely depend on a lot
more than just the cores that are running but I have no idea what
you're doing with it (remote server/desktop/what ever) so there's
likely a lot that will come into play.

Stewart Samuels

2016-09-08 12:57:07 UTC

Thanks Peter,

This will be very disappointing if we cannot enable all the cpus.

BTW, when you refer to upstream here, is it the Redhat team or the
Kernel team beyond?

Stewart

Nope, they are upstream kernel (and possibly even upstream u-boot)
specific. The only default we set in this regard that may, or may not,
be Fedora specific is we use the On Demand governor as the default.
This is architecture in dependent default across Fedora.
I doubt the Ubuntu build ships an upstream mainline kernel but then I
don't follow any of what they do so TBH not sure there, I also have no
idea what they set their default policy to.
So doing a quick google for "cpufreq" I get some of the following
links that look remotely relevant, no idea how much they are, sorry.
https://docs.fedoraproject.org/en-US/Fedora/15/html/Power_Management_Guide/cpufreq_governors.html
https://wiki.archlinux.org/index.php/CPU_frequency_scaling
https://www.kernel.org/doc/Documentation/cpu-freq/governors.txt
https://www.pantz.org/software/cpufreq/usingcpufreqonlinux.html
http://www.ibm.com/developerworks/library/l-cpufreq-1/index.html
https://wiki.debian.org/HowTo/CpuFrequencyScaling

So it's shut them off, it's something with the way the big.LITTLE
stuff works, so it's basically as expected. I believe it's handled as
part of the cpufreq policies from user space but I've done little with
the b.L stuff so I'm not sure. I'd try with the performance policy
first.
In terms of speed vs other distros, it would likely depend on a lot
more than just the cores that are running but I have no idea what
you're doing with it (remote server/desktop/what ever) so there's
likely a lot that will come into play.

Peter Robinson

2016-09-08 13:01:04 UTC

Post by Stewart Samuels
Thanks Peter,
This will be very disappointing if we cannot enable all the cpus.
BTW, when you refer to upstream here, is it the Redhat team or the Kernel
team beyond?

Never Red Hat. Fedora is upstream to Red Hat, so upstream means the
linux kernel upstream at kernel.org and the kernel at large.

Nope, they are upstream kernel (and possibly even upstream u-boot)
specific. The only default we set in this regard that may, or may not,
be Fedora specific is we use the On Demand governor as the default.
This is architecture in dependent default across Fedora.
I doubt the Ubuntu build ships an upstream mainline kernel but then I
don't follow any of what they do so TBH not sure there, I also have no
idea what they set their default policy to.
So doing a quick google for "cpufreq" I get some of the following
links that look remotely relevant, no idea how much they are, sorry.
https://docs.fedoraproject.org/en-US/Fedora/15/html/Power_Management_Guide/cpufreq_governors.html
https://wiki.archlinux.org/index.php/CPU_frequency_scaling
https://www.kernel.org/doc/Documentation/cpu-freq/governors.txt
https://www.pantz.org/software/cpufreq/usingcpufreqonlinux.html
http://www.ibm.com/developerworks/library/l-cpufreq-1/index.html
https://wiki.debian.org/HowTo/CpuFrequencyScaling

So it's shut them off, it's something with the way the big.LITTLE
stuff works, so it's basically as expected. I believe it's handled as
part of the cpufreq policies from user space but I've done little with
the b.L stuff so I'm not sure. I'd try with the performance policy
first.
In terms of speed vs other distros, it would likely depend on a lot
more than just the cores that are running but I have no idea what
you're doing with it (remote server/desktop/what ever) so there's
likely a lot that will come into play.

Stewart Samuels

2016-09-09 00:48:45 UTC

Based on what I've read in the Fedora Docs, I should be able to change
the cpu governor by using the following command:

cpupower frequency-set --governor [governor]

However, if I replace the [governor] string with "userspace" (quotes
not include)
nothing seems to happen. I do not get any errors from the command and
"ondemand" seems to remain the governor, as shown by the following command:

[***@myodroid ~]# cpupower frequency-info --policy
analyzing CPU 0:
current policy: frequency should be within 200 MHz and 1.30
GHz.
The governor "ondemand" may decide
which speed to use
within this range.

"userspace" is an available governor on my system, as shown by the
following command:

[***@myodroid ~]# cpupower frequency-info --governors
analyzing CPU 0:
available cpufreq governors: conservative userspace
powersave ondemand performance

In fact, it doesn't seem to matter to which governor I set it. Nothing
changes.

Is there something I am missing? What could be happening here?

Stewart

Post by Stewart Samuels
Thanks Peter,
This will be very disappointing if we cannot enable all the cpus.
BTW, when you refer to upstream here, is it the Redhat team or the Kernel
team beyond?

Never Red Hat. Fedora is upstream to Red Hat, so upstream means the
linux kernel upstream at kernel.org and the kernel at large.

Nope, they are upstream kernel (and possibly even upstream u-boot)
specific. The only default we set in this regard that may, or may not,
be Fedora specific is we use the On Demand governor as the default.
This is architecture in dependent default across Fedora.
I doubt the Ubuntu build ships an upstream mainline kernel but then I
don't follow any of what they do so TBH not sure there, I also have no
idea what they set their default policy to.
So doing a quick google for "cpufreq" I get some of the following
links that look remotely relevant, no idea how much they are, sorry.
https://docs.fedoraproject.org/en-US/Fedora/15/html/Power_Management_Guide/cpufreq_governors.html
https://wiki.archlinux.org/index.php/CPU_frequency_scaling
https://www.kernel.org/doc/Documentation/cpu-freq/governors.txt
https://www.pantz.org/software/cpufreq/usingcpufreqonlinux.html
http://www.ibm.com/developerworks/library/l-cpufreq-1/index.html
https://wiki.debian.org/HowTo/CpuFrequencyScaling