Raid6 check performance regression 5.15 -> 5.16

[Larkin Lowrey <llowrey@xxxxxxxxxxxxxxxxx>]

I am seeing a 'check' speed regression between kernels 5.15 and 5.16. 
One host with a 20 drive array went from 170MB/s to 11MB/s. Another host 
with a 15 drive array went from 180MB/s to 43MB/s. In both cases the 
arrays are almost completely idle. I can flip between the two kernels 
with no other changes and observe the performance changes.

Is this a known issue?

--Larkin