On 17/12/20 14:09, mark wrote:
-----Original message-----
From: mark mark@havak.nl Sent: Monday, December 14, 2020 6:15 PM To: Pablo Sebastián Greco pablo@fliagreco.com.ar; Conversations around CentOS on ARM hardware arm-dev@centos.org Subject: RE: [Arm-dev] unable to configure zram-swap on RPI 4 8G model (32bit)
-----Original message-----
From: Pablo Sebastián Greco pablo@fliagreco.com.ar Sent: Monday, December 14, 2020 6:00 PM To: Conversations around CentOS on ARM hardware arm-dev@centos.org; mark
Subject: Re: [Arm-dev] unable to configure zram-swap on RPI 4 8G model (32bit)
On 14/12/20 13:43, mark wrote:
-----Original Message----- From: Pablo Sebastián Greco pablo@fliagreco.com.ar Sent: maandag 14 december 2020 17:20 To: Conversations around CentOS on ARM hardware arm-dev@centos.org;
mark
Subject: Re: [Arm-dev] unable to configure zram-swap on RPI 4 8G model
(32bit)
On 14/12/20 11:42, mark wrote:
Being aware using zram-swap is not a default feature on the CentOS Userland for armv7hl, Still want to share the problem I ran in to.
I turns out the arm 32bit kernel with large memory support OOPS if zram-swap
is deployed if the system has more than 4GB ram.
I'm a heavy user of zram-swap, even not being default, but I have only
used
with devices that have 2G max, this is interesting. Does it still happen
if
you limit the size?
Did not test limiting the ram to 4GB myself jet, it does according to
:
https://github.com/raspberrypi/linux/issues/3839#issuecomment-723027652
I meant limiting the size of the zram-swap
No the size of the swap does not seem matter: I tried 512, 1024 and 4096MB
On a RPI4 4GB model it works just fine, on a 8GB model I get a "Internal error: Oops: 207"
BTW running a fresh homebrew image of CentOS 7.9.2009 without a swap-partition and kernel: 5.4.72-v7l.1.el7 #1 SMP Wed Oct 21 17:20:56 UTC 2020 armv7l armv7l armv7l GNU/Linux
This issue seems to be addressed (verry recently) in kernel 5.4.81 (1)
As mentioned this is verry recently, version 5.4.81 is just 12 day's
old..
However if there is a testbuild of this rpi2-kernel4: I'm eager to test
it
Just a heads-up,
I could not figure out how to make a test build of a kernel => 5.4.81 based on the current raspberrypi2-kernel4-5.4.72 kernel. Not knowledgeable enough to update the rpi-5.4.x.patch... My Bad
However was able to rebuild the current kernel with the patch mentioned in the commit (1); needed to include an other, quite harmless looking, patch in order to get it applied clean
That's even better actually, because we can confirm that it actually that patch that fixes it, thanks!!!
Just curious, how long did it take to rebuild the kernel?
Long story short, zram-swap works on my RPI4 8G model:
# swapon --show NAME TYPE SIZE USED PRIO /dev/zram0 partition 3.7G 0B -2
# uname -a Linux localhost 5.4.72-v7l.1.1.el7 #1 SMP Thu Dec 17 16:13:03 CET 2020 armv7l armv7l armv7l GNU/Linux
# free -m total used free shared buff/cache available Mem: 7876 94 7469 16 312 7691 Swap: 3755 0 3755
In my (probably short lived) git repo the changes I made: https://github.com/markVnl/Centos-raspberrypi2-kernel/tree/zram-swap-oops
There's no test build yet, I'm still adjusting to what happened last week, but hopefully we'll have a new kernel soon
Pablo.
Arm-dev mailing list Arm-dev@centos.org https://lists.centos.org/mailman/listinfo/arm-dev
Pablo.