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

Mon Dec 14 17:20:53 UTC 2020
mark <mark at havak.nl>


-----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 (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 😉
> > There's no test build yet, I'm still adjusting to what happened last
> > week, but hopefully we'll have a new kernel soon
> >> 1) https://github.com/raspberrypi/linux/commit/1bef5f25a69234613b92a0e2456870fee4a57efc
> >>
> >>    
> > Pablo.
> >
> > _______________________________________________
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>