Re: PROBLEM: bcache related kernel BUG() since Linux 5.12

[Coly Li <colyli@suse.de>]

On 6/4/21 9:38 PM, Rolf Fokkens wrote:
> Hoi Coly,
>
> The common applications I used, which for sure benefit from bcache:
>
>   * Gnome 3.38
>   * Libreoffice-7.0.6.2
>   * teams-1.4.00.7556
>   * Terminator
>   * Evolution-3.38.4
>   * Thunderbird evolution-3.38.4
>   * thunderbird-78.10.1
>   * firefox-88.0.1
>   * google-chrome-stable-91.0.4472.77
>
> So it's a typical desktop wordload with most I/O during startup of
> applications.
>
> For overall stress/stability testing:
>
>   * Doom (steam/proton)
>   * Rise of the Tombraider (steam)
>   * The Witcher 3 (steam)
>
> Overall stats after (should have done before) starting the steam games:
>
> bash-5.0$ bcache-status
> --- bcache ---
> UUID                        b191549d-4455-43ca-b9b8-8e32dd68751c
> Block Size                  512 B
> Bucket Size                 512.00 KiB
> Congested?                  False
> Read Congestion             0.0ms
> Write Congestion            20.0ms
> Total Cache Size            128 GiB
> Total Cache Used            128 GiB    (100%)
> Total Cache Unused          0 B    (0%)
> Evictable Cache             106 GiB    (83%)
> Replacement Policy          [lru] fifo random
> Cache Mode                  writethrough [writeback] writearound none
> Total Hits                  3006361    (95%)
> Total Misses                126463
> Total Bypass Hits           4552    (68%)
> Total Bypass Misses         2061
> Total Bypassed              730.1 MiB
> bash-5.0$
>
> Hope this gives you a good impression of the workload.
>
> Let me know if you like me to do specific stress tests.

[snipped]

Hi Rolf and Thorsten,

I run the following workloads for 48+ hours, no panic or data corruption
so far,
- tar, untar, gzip, gunzip
- git clone/fsck/gc/archive
- copy iso files, checksum calculation and check for all the iso files
- kernel source code compiling
- ext4 file system check

The fix might not be perfect yet, but IMHO we should provide a fix now.
If there is any other known issue triggered, let's fix and verify later.

Thank you all for the testing and verification these days.

Coly Li