sshadow
Posts: 2
Joined: Wed Jan 01, 2020 8:28 pm

Re: Pi4 64-bit raspbian kernel for testing - Focus on Pi4

Thu Jan 02, 2020 4:51 am

I note that the 64-bit kernel keeps my Pi4 significantly cooler than the 32-bit one.
64-bit temp: ~125 F, or ~51.5 C
32-bit temp: ~150 F, or ~65.5 C

This is without cooling or a heat sink. When I turn my fan on, both numbers plunge to more reasonable values.

dom
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 5378
Joined: Wed Aug 17, 2011 7:41 pm
Location: Cambridge

Re: Pi4 64-bit raspbian kernel for testing - Focus on Pi4

Thu Jan 02, 2020 8:00 pm

sshadow wrote:
Thu Jan 02, 2020 4:51 am
I note that the 64-bit kernel keeps my Pi4 significantly cooler than the 32-bit one.
Are you comparing the updating firmware/kernel with and without arm_64bit=1?
Or are you comparing and old firmware/kernel with a new one?

The temperature difference seems more likely to come from firmware improvements than 64bit.

sshadow
Posts: 2
Joined: Wed Jan 01, 2020 8:28 pm

Re: Pi4 64-bit raspbian kernel for testing - Focus on Pi4

Thu Jan 02, 2020 8:51 pm

You're right, I was comparing the old firmware with the new.
dom wrote:The temperature difference seems more likely to come from firmware improvements than 64bit.
That would explain it.

noma
Posts: 1
Joined: Tue Jan 07, 2020 9:21 pm

Re: Pi4 64-bit raspbian kernel for testing - Focus on Pi4

Tue Jan 07, 2020 9:29 pm

gishten wrote:
Tue Oct 22, 2019 2:04 pm
I'm having trouble running rtorrent 0.9.7 on this kernel. It crashes intermittently, though never running longer than ~4 hours.

Code: Select all

Caught SIGBUS, dumping stack:
rtorrent() [0x1ed84]
/lib/arm-linux-gnueabihf/libc.so.6(__default_rt_sa_restorer+0) [0xf75a3130]
/usr/lib/arm-linux-gnueabihf/libtorrent.so.20(+0xb9f9c) [0xf7a39f9c]
/usr/lib/arm-linux-gnueabihf/libtorrent.so.20(_ZN7torrent9PollEPoll7performEv+0xdc) [0xf79af4e8]
/usr/lib/arm-linux-gnueabihf/libtorrent.so.20(_ZN7torrent9PollEPoll7do_pollExi+0xa8) [0xf79af69c]
/usr/lib/arm-linux-gnueabihf/libtorrent.so.20(_ZN7torrent11thread_base10event_loopEPS0_+0x17c) [0xf79e8b7c]
rtorrent() [0x1d8f4]
/lib/arm-linux-gnueabihf/libc.so.6(__libc_start_main+0x10c) [0xf758d718]

Error: Success
Signal code '1': Invalid address alignment.
Fault address: 0xe8ad91
The fault address is not part of any chunk.
Aborted
Having a similar issue with Borg Backup, see details here:

https://github.com/borgbackup/borg/issues/4891

It looks like the handling for unaligned memory accesses is different in the 32 and 64-bit kernel.

https://www.kernel.org/doc/html/v5.4/ar ... nment.html

This might be related, as well:

https://github.com/raspberrypi/linux/issues/2283
You should have mentioned that yours was a 64-bit build - alignment trap is not available on any arm64 kernel.
Looks like all the software causing unaligned accesses will be problematic on the 64-bit kernel, if this statement is still true.

fruitoftheloom
Posts: 21314
Joined: Tue Mar 25, 2014 12:40 pm
Location: Delightful Dorset

Re: Pi4 64-bit raspbian kernel for testing - Focus on Pi4

Fri Jan 10, 2020 9:48 am

akschu wrote:
Thu Dec 26, 2019 1:15 am
RandyOo wrote:
Thu Nov 14, 2019 10:35 pm
Reporting in... I bought a 4GB Pi4 with the sole intent of having it perform the role of a small ZFS-based NAS, now that it has USB 3.0, gigabit ethernet, and lots more RAM. I had already managed to get ZFS up and running on Pi3, so I knew it could be done.

I managed to get ZFS compiled and running on the 32 bit kernel, but kept encountering killed tasks due to OOM (out-of-memory) errors while running a simple (but large) rsync between two ZFS pools, and even though swap was set up and present, it was unused. Seems to be some kind of manifestation of ZFS not being happy on a 32-bit kernel.

After conquering the learning curve of getting a chroot environment set up to compile arm64, and kernel source downloaded from git and built, I finally managed to get the ZFS module compiled for arm64, and subsequently installed.

Now, with the 64-bit kernel running, the memory issue is gone, and throughput on the rsync file copy between two USB 3.0 drives appears to have doubled! :D

Although I do enjoy learning, I'll look forward to the day when ZFS is just an apt-get install away... :lol:
How were you able to compile the ZFS kernel module? I'm trying to do the same, but there isn't a kernel-headers or kernel-source package I can find, and downloading the official raspberrypi kernel source and building it results in "gcc: error: unrecognized command line option ‘-mgeneral-regs-only’"

I can't figure out how to build modules for this kernel. Any help would be greatly appreciated.

schu

https://www.realworldtech.com/forum/?th ... tid=189841
Retired disgracefully.....
This at present is my daily "computer" https://www.asus.com/us/Chrome-Devices/Chromebit-CS10/

tw99
Posts: 13
Joined: Thu Sep 20, 2012 4:54 pm

unifi wifi controller is working

Fri Jan 10, 2020 1:14 pm

I was interested to try the 64 bit kernel as a way of enabling the Unifi WiFi controller to run more effectively on a PI. While it can be run in 32 bit mode, it is somewhat compromised. This software has a bunch of annoying dependencies. It uses mongodb and needs a 64 bit version of mongo in order to store more than a few weeks worth of statistics without crashing. It also requires Java 8 due to some dependencies that have been removed from later versions of OpenJDK.

The good news is I was able to get it working, roughly as follows:

- PI4 with latest buster, 64 bit kernel enabled
- Use debootstrap to install a basic 64 bit user environment
- schroot into this environment and use glennr's script to install Unifi. This includes openjdk8, unifi, mongodb (the script is smart enough to grab the ubuntu version of mongodb, since debian no longer include it)
- use a persistent schroot session to start the unifi service

I may look into systemd-nspawn in future, but this seems to be good enough for now.

jdonald
Posts: 425
Joined: Fri Nov 03, 2017 4:36 pm

Re: Pi4 64-bit raspbian kernel for testing - Focus on Pi4

Sat Jan 18, 2020 5:14 am

moirainesedai wrote:
Sat Sep 28, 2019 3:11 am
Is it possible to run 64-bit docker images with this kernel? e.g. `docker run arm64v8/fedora:31 uname -a` does not work for me...
In that GitHub issue: https://github.com/docker/distribution/issues/3008 they've posted some workarounds. You can add either --privileged or --security-opt seccomp:unconfined. For example:

Code: Select all

docker run --security-opt seccomp:unconfined -it arm64v8/fedora:31
Then you'll be in a Fedora container where you can install aarch64 packages via yum.

Wish I had tried --privileged years ago!

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