Rework cache layer to have less lock contention. This code still needs a complete rewrite.  But at least it's now more intelligible.  Before the changes most of the page data was being copied while holding the lock. Obviating the purpuse of the cache_{read|write}_pages_get() routines.
Rework cache layer to have less lock contention.
This code still needs a complete rewrite.  But at least it's now
more intelligible.  Before the changes most of the page data was being
copied while holding the lock. Obviating the purpuse of the
cache_{read|write}_pages_get() routines.

tacketar/lstore,tacketar/lstore,tacketar/lstore,accre/lstore,accre/lstore,accre/lstore,accre/lstore,tacketar/lstore