Scrub incredibly slow with 13.0-RC3 (as well as RC1 & 2)

[Martin Simmons]

>>>>> On Mon, 22 Mar 2021 11:17:42 +0100, Mathieu Chouquet-Stringer said:
> 
>   PID USER      PRI  NI  VIRT   RES S CPU% MEM%   TIME+  Command
>     0 root      -16   0     0 12976 S 22.5  0.0  9h45:36 kernel
>     1 root       24   0 11824    32 S  0.0  0.0  0:00.36 /sbin/init
>  3453 root       20   0 17668  2224 S  0.0  0.0  0:00.48 /usr/local/sbin/smartd -A /usr/local/
>  3974 root       52   0 12892    48 S  0.0  0.0  0:00.00 /usr/libexec/getty Pc ttyv0
>  4973 root       52   0 12892    48 S  0.0  0.0  0:00.00 /usr/libexec/getty Pc ttyv1
>  5618 root       52   0 12892    48 S  0.0  0.0  0:00.00 /usr/libexec/getty Pc ttyv2
>  5974 root       52   0 12892    48 S  0.0  0.0  0:00.00 /usr/libexec/getty Pc ttyv3
>  6320 root       52   0 12892    48 S  0.0  0.0  0:00.00 /usr/libexec/getty Pc ttyv4
>  6386 root       20   0 39188  2932 S  0.0  0.0  0:00.65 /usr/local/sbin/nmbd --daemon --confi
> 
> Any idea how I could help debug that?

You could try:

procstat -kk 0

to get an overview of what the kernel threads are doing.

__Martin