Problems with Zram on H2/3/5 boards - zram: Decompression failed! err=-22

Hammy · November 20, 2020

Armbianmonitor:

Good evening,

I ran into some problems with sbc-bench on a couple of Allwinner boards Orange Pi Zero, Orange Pi Zero+, Orange Pi One and Nanopi Neo 2 spcifically. The 7 Zip benchmark causes the following error:

./sbc-bench.sh: Zeile 611: 4206 Bus-Zugriffsfehler "${SevenZip}" b >> ${TempLog}

Most likely due to a problem with the ZRam:

zram: Decompression failed! err=-22

This happens on all boards under Debian and focal with different SD cards and power supplies. The benchmark ran previously on this setups without any issues – unfortunately I don’t know when it stopped working and hence cannot narrow down the change that caused the problem.

The benchmark results and armbianmonitor output from the Orange Pi one as an example:

http://ix.io/2EPZ

http://ix.io/2ES2

Is this a known issue? Is there a solution?

Daniel

Hammy · November 21, 2020

Small update:

going back to Armbian 20.08.17 Buster with Linux 5.4.62-sunxi64 "solves" the problem.

http://ix.io/2EYt

Can anyone confirm this behavior?

Daniel

Igor · November 21, 2020

I didn't checked yet, but I read on OpenHAb forum that their ZRAM implementation is failing. On Rpi. Which makes me believe the problem comes from the upstream.

Icenowy · November 22, 2020

Could you try to switch the ZRAM algorithm to zstd to try out?

This seems to be fixing issue when I try to port Armbian to PineCube.

Hammy · November 22, 2020

Thanks for the info, is there any work around?

Switching to zstd caused the same error and crashed the board while benchmarking. After a reboot: http://ix.io/2F3t - Interestingly it says:

### Activated 1 lzo-rle zram swap devices with 491 MB each

While

root@orangepizero:~# zramctl

NAME ALGORITHM DISKSIZE DATA COMPR TOTAL STREAMS MOUNTPOINT

/dev/zram1 zstd 491,6M 4K 58B 4K 4 [SWAP]

/dev/zram0 zstd 50M 1,4M 184,1K 572K 4 /var/log

Daniel

Icenowy · November 24, 2020

@IgorSeems to be https://lore.kernel.org/linux-mm/20201105170249.387069-1-minchan@kernel.org/ .

By the way in mainline kernel the "fix" seems to be dropping ZSMALLOC_PGTABLE_MAPPING , see https://www.spinics.net/lists/stable/msg428110.html (it's already in linux-next).