On Sat, 2020-09-12 at 10:59 -0700, Linus Torvalds wrote:
[...]

Any other suggestions than those (a)-(d) ones above?

What about revert and try to fix the outliers?  Say by having a timer
set when a process gets put to sleep waiting on the page lock.  If the
time fires it gets woken up and put at the head of the queue.  I
suppose it would also be useful to know if this had happened, so if the
timer has to be reset because the process again fails to win and gets
put to sleep it should perhaps be woken after a shorter interval or
perhaps it should spin before sleeping.

I'm not advocating this as the long term solution, but it could be the
stopgap while people work on (c).

James