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

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

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.

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.

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

@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).

https://github.com/armbian/build/pull/2377 Tested to fix the issue.

Awesome guys, when will the change be in the current build?

 

Out of curiosity: What is “ZSMALLOC_PGTABLE_MAPPING“ actually doing?