CVS log for src/sys/uvm/uvm_pdpolicy.h

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uvm_pdpolicy.h: Fix missing forward declarations and includes.

Start trying to reduce cache misses on vm_page during fault processing.

- Make PGO_LOCKED getpages imply PGO_NOBUSY and remove the latter.  Mark
  pages busy only when there's actually I/O to do.

- When doing COW on a uvm_object, don't mess with neighbouring pages.  In
  all likelyhood they're already entered.

- Don't mess with neighbouring VAs that have existing mappings as replacing
  those mappings with same can be quite costly.

- Don't enqueue pages for neighbour faults unless not enqueued already, and
  don't activate centre pages unless uvmpdpol says its useful.

Also:

- Make PGO_LOCKED getpages on UAOs work more like vnodes: do gang lookup in
  the radix tree, and don't allocate new pages.

- Fix many assertion failures around faults/loans with tmpfs.

Merge changes from current as of 20200406

Sync with head.

UVM locking changes, proposed on tech-kern:

- Change the lock on uvm_object, vm_amap and vm_anon to be a RW lock.
- Break v_interlock and vmobjlock apart.  v_interlock remains a mutex.
- Do partial PV list locking in the x86 pmap.  Others to follow later.

- Add and use wrapper functions that take and acquire page interlocks, and pairs
  of page interlocks.  Require that the page interlock be held over calls to
  uvm_pageactivate(), uvm_pagewire() and similar.

- Solve the concurrency problem with page replacement state.  Rather than
  updating the global state synchronously, set an intended state on
  individual pages (active, inactive, enqueued, dequeued) while holding the
  page interlock.  After the interlock is released put the pages on a 128
  entry per-CPU queue for their state changes to be made real in batch.
  This results in in a ~400 fold decrease in contention on my test system.
  Proposed on tech-kern but modified to use the page interlock rather than
  atomics to synchronise as it's much easier to maintain that way, and
  cheaper.

pagedaemon:

- Use marker pages to keep place in the queue when scanning, rather than
  relying on assumptions.

- In uvmpdpol_balancequeue(), lock the object once instead of twice.

- When draining pools, the situation is getting desperate, but try to avoid
  saturating the system with xcall, lock and interrupt activity by sleeping
  for 1 clock tick if being continually awoken and all pools have been
  cycled through at least once.

- Pause & resume the freelist cache during pool draining.

PR kern/54209: NetBSD 8 large memory performance extremely low
PR kern/54210: NetBSD-8 processes presumably not exiting
PR kern/54727: writing a large file causes unreasonable system behaviour

Break the global uvm_pageqlock into a per-page identity lock and a private
lock for use of the pagedaemon policy code.  Discussed on tech-kern.

PR kern/54209: NetBSD 8 large memory performance extremely low
PR kern/54210: NetBSD-8 processes presumably not exiting
PR kern/54727: writing a large file causes unreasonable system behaviour

Separate object-less anon pages out of the active list if there is no swap
device.  Make uvm_reclaimable and uvm.*estimatable understand colors and
kmem allocations.

Major changes to uvm.
Support multiple collections (groups) of free pages and run the page
reclaimation algorithm on each group independently.

- sync with head.
- move sched_changepri back to kern_synch.c as it doesn't know PPQ anymore.

sync with head.

Replace the Mach-derived boolean_t type with the C99 bool type.  A
future commit will replace use of TRUE and FALSE with true and false.

sync with head.

Sync with head.

file uvm_pdpolicy.h was added on branch yamt-lazymbuf on 2006-12-30 20:51:05 +0000

merge yamt-pdpolicy branch.
	- separate page replacement policy from the rest of kernel
	- implement an alternative replacement policy

separate page replacement policy from the rest of kernel.

file uvm_pdpolicy.h was initially added on branch yamt-pdpolicy.