We are now out of aflags bits, whereas the "flags" field only makes use
of five of its sixteen bits, so narrow "flags" to eight bits. I have no
intention of adding a new aflag in the near future, but would like to
combine the aflags, queue and act_count fields into a single atomically
updated word. This will allow vm_page_pqstate_cmpset() to become much
simpler and is a step towards eliminating the use of the page lock array
in updating per-page queue state.
The change modifies the layout of struct vm_page, so bump
__FreeBSD_version.
Reviewed by: alc, dougm, jeff, kib
Sponsored by: Netflix, Intel
Differential Revision: https://reviews.freebsd.org/D22397
3a2ba9974d