Quite a few machines with Adaptec controllers seems to hang for a few
tens of seconds to a few minutes before things start to work normally
again for a while:
https://urldefense.com/v3/__https://bugzilla.kernel.org/show_bug.cgi?id=217599__;!!ACWV5N9M2RV99hQ!L26RD0hu99l3f709EFnXU_V7OaB1jG4Hi7BjKvxRuhDWKFmjrgfksLuXA6eBrBCRtOT8JcRRUvzRsHbyEm41r7tL_pbDfw$
That problem is apparently caused by 9dc704dcc09eae ("scsi: aacraid:
Reply queue mapping to CPUs based on IRQ affinity") [v6.4-rc7]. That
commit despite a warning of mine to Sasha recently made it into 6.1.53
-- and that way apparently recently reached more users recently, as
quite a few joined that ticket.