[Arm-dev] unable to configure zram-swap on RPI 4 8G model (32bit)

Tue Jan 19 13:36:04 UTC 2021
mark <mark at havak.nl>

-----Original message-----
> From: mark <mark at havak.nl>
> Sent: Thursday December 17th, 2020 22:10
> To: Pablo Sebastián Greco <pablo at fliagreco.com.ar>; Conversations around CentOS on ARM hardware <arm-dev at centos.org>
> Subject: RE: [Arm-dev] unable to configure zram-swap on RPI 4 8G model (32bit)
> 
> -----Original message-----
> > From: Pablo Sebastián Greco <pablo at fliagreco.com.ar>
> > Sent: Thursday, December 17, 2020 9:39 PM
> > To: mark <mark at havak.nl>; Conversations around CentOS on ARM hardware <arm-dev at centos.org>
> > Subject: Re: [Arm-dev] unable to configure zram-swap on RPI 4 8G model (32bit)
> >
> >
> > On 17/12/20 14:09, mark wrote:
> > > -----Original message-----
> > >> From: mark <mark at havak.nl>
> > >> Sent: Monday, December 14, 2020 6:15 PM
> > >> To: Pablo Sebastián Greco <pablo at fliagreco.com.ar>; Conversations around
> > CentOS on ARM hardware <arm-dev at centos.org>
> > >> Subject: RE: [Arm-dev] unable to configure zram-swap on RPI 4 8G model
> > (32bit)
> > >>
> > >>
> > >>
> > >> -----Original message-----
> > >>> From: Pablo Sebastián Greco <pablo at fliagreco.com.ar>
> > >>> Sent: Monday, December 14, 2020 6:00 PM
> > >>> To: Conversations around CentOS on ARM hardware <arm-dev at centos.org>;
> > mark
> > >> <mark at havak.nl>
> > >>> 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 at fliagreco.com.ar>
> > >>>> Sent: maandag 14 december 2020 17:20
> > >>>> To: Conversations around CentOS on ARM hardware <arm-dev at centos.org>;
> > >> mark
> > >>> <mark at havak.nl>
> > >>>> 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 (very recently) in kernel 5.4.81
> (1)
> > >>>>>
> > >>>>> As mentioned this is very 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?
> 
> About 01:45; (mock) state.log building on an odroid hc1:
> 
> 2020-12-17 15:46:56,190 - Mock Version: 2.7
> 2020-12-17 15:46:58,637 - Start: yum update
> 2020-12-17 15:47:11,414 - Finish: yum update
> 2020-12-17 15:47:11,458 - Finish: chroot init
> 2020-12-17 15:47:11,470 - Start: build phase for raspberrypi2-5.4.72-v7.1.1.ns7.src.rpm
> 2020-12-17 15:47:11,488 - Start: build setup for raspberrypi2-5.4.72-v7.1.1.ns7.src.rpm
> 2020-12-17 15:48:41,143 - Finish: build setup for raspberrypi2-5.4.72-v7.1.1.ns7.src.rpm
> 2020-12-17 15:48:41,147 - Start: Outputting list of installed packages
> 2020-12-17 15:48:41,842 - Finish: Outputting list of installed packages
> 2020-12-17 15:48:41,843 - Start: rpmbuild raspberrypi2-5.4.72-v7.1.1.ns7.src.rpm
> 2020-12-17 17:28:49,731 - Finish: rpmbuild raspberrypi2-5.4.72-v7.1.1.ns7.src.rpm
> 2020-12-17 17:28:51,856 - Finish: build phase for raspberrypi2-5.4.72-v7.1.1.ns7.src.rpm
> 2020-12-17 17:28:51,884 - Start: clean chroot
> 2020-12-17 17:30:32,678 - Finish: clean chroot
> 2020-12-17 17:30:32,683 - Finish: run
> 
> probably going to move to a (faster) platform in the future;
> it is hard to just say goodbye to a device that served you well :)
> 
> >
> > > 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

Hi, is there a status update on this?

Did run your test build (5.4.84-v8.1.el7.armhfp) from buildlogs it solved the issue 
and just saw (as in now) a build of 5.4.88-v8.1.el7.armhfp, wil test that one too

> > >>>>> 1) https://github.com/raspberrypi/linux/commit/1bef5f25a69234613b92a0e2456870fee4a57efc
> > >>>>>
> > >>>>>    
> > >>>> Pablo.
> > >>>>
> > >>>> _______________________________________________
> > >>>> Arm-dev mailing list
> > >>>> Arm-dev at centos.org
> > >>>> https://lists.centos.org/mailman/listinfo/arm-dev
> > Pablo.
> >
>