Verdict - ZRAM for lower end machines

[amethyst]

Not impressed with this gimmick. Performance of my 2Gb Ram machine suffered in the end (it basically grinded to an almost halt and the situation persisted even after closing applications and unmounting a partition). I've now got rid of that code in rc.sysinit. Much better now. I do not recommend this for limited RAM machines.
EDIT:Revisiting this. I may have been a bit hasty with this verdict. Been using zram for hours streaming on my old laptop. No problems yet. My previous problem may have been related to something going wrong with a huge download of several gigs (the download failed and the machine stalled). More testing needed.

[LateAdopter]

I had a lot of problems with temporary hangs and screen graphics corruption when testing various Ubuntu 22.04 based Puppy variants on my Intel Braswell N3150 system with 4GB RAM.
Removing ZRAM swap was one of the things that was needed to fix it.

I don't think ZRAM swap was directly responsible for the problem since it was never used and never took any RAM.

My theory was that it was the number of different compression algorithms being used, by Puppy, concurrently in the kernel, could overrun some resource in the CPU and cause long delays processing compressed files.

One common occurrence was that the top pane of the exit (leave) panel would be garbled or black.

[dimkr]

@LateAdopter Have you tried to reduce swappiness?

Code: Select all

sudo sysctl vm.swappiness=5
echo vm.swappiness=5 | sudo tee /etc/sysctl.conf

When swappiness is low, your system won't use zram swap until it's really running low on RAM, so CPU consumption should be unaffected during normal use.

[LateAdopter]

No, because it never did any swapping while I was testing. I checked the available RAM and it never changed. I guessed that it just introduced yet another compressor for the kernel to handle.

I re-squashed some of the SFS so that they all used the same type of compression. I also rolled back to an older kernel because the Intel driver kept losing the connection to the HDMI display, with 5.15 and later. I'd get a grey screen but the system was still running and I could shut down properly.

I have a copy of jrb's jammy64pup that works OK with a 5.10 kernel with ZRAM swap still loaded. That's why I don't think ZRAM swap is directly implicated.

I think there are various difficulties running Jammy on old Intel hardware.