[$] Warming up to frozen pages for networking

When the 6.14 kernel is released later this month, it will include the
usual set of internal changes that users should never notice, with the
possible exception of changes that bring performance improvements. One of
those changes is frozen pages, a
memory-management optimization that should fly mostly under the radar.
When Hannes Reinecke reported a
crash in 6.14, though, frozen pages suddenly came into view. There is a
workaround for this problem, but it seems there is a fair
amount of work to be done that nobody had counted on to solve the problem
properly.