The third 5.5 kernel prepatch is out; it
was a bit bigger than Linus would have liked.
“Anyway, I’m hoping rc3 is a one-off. In fact, with the holiday season
coming up, I’d be very surprised indeed if it wasn’t. So I suspect
things will calm down a lot over the next couple of weeks, but please
do use the down-time to do some extra testing instead, ok?“

Source: LWN.net – Kernel prepatch 5.5-rc3