[src/trunk]: src/sys/uvm Counter tweaks:

[ad <ad%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/a8274b4af027
branches:  trunk
changeset: 934420:a8274b4af027
user:      ad <ad%NetBSD.org@localhost>
date:      Thu Jun 11 22:25:51 2020 +0000

description:
Counter tweaks:

- Don't need to count anonpages+filepages any more; clean+unknown+dirty for
  each kind of page can be summed to get the totals.

- Track the number of free pages with a counter so that it's one less thing
  for the allocator to do, which opens up further options there.

- Remove cpu_count_sync_one(). It has no users and doesn't save a whole lot.
  For the cheap option, give cpu_count_sync() a boolean parameter indicating
  that a cached value is okay, and rate limit the updates for cached values
  to hz.

diffstat:

 sys/uvm/uvm_pglist.c |  5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diffs (26 lines):

diff -r a52a05b1e7dd -r a8274b4af027 sys/uvm/uvm_pglist.c
--- a/sys/uvm/uvm_pglist.c      Thu Jun 11 22:25:44 2020 +0000
+++ b/sys/uvm/uvm_pglist.c      Thu Jun 11 22:25:51 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uvm_pglist.c,v 1.83 2020/06/11 19:20:47 ad Exp $       */
+/*     $NetBSD: uvm_pglist.c,v 1.84 2020/06/11 22:25:51 ad Exp $       */
 
 /*-
  * Copyright (c) 1997, 2019 The NetBSD Foundation, Inc.
@@ -35,7 +35,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_pglist.c,v 1.83 2020/06/11 19:20:47 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_pglist.c,v 1.84 2020/06/11 22:25:51 ad Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -98,6 +98,7 @@
 #endif
        LIST_REMOVE(pg, pageq.list);
        pgb->pgb_nfree--;
+       CPU_COUNT(CPU_COUNT_FREEPAGES, -1);
        if (pg->flags & PG_ZERO)
                CPU_COUNT(CPU_COUNT_ZEROPAGES, -1);
        pg->flags = PG_CLEAN;