[src/trunk]: src/sys/arch/alpha/alpha From the Infinitesimal Optimizations De...

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

details:   https://anonhg.NetBSD.org/src/rev/d6e0d6ed9292
branches:  trunk
changeset: 1017509:d6e0d6ed9292
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Tue Dec 29 17:16:15 2020 +0000

description:
>From the Infinitesimal Optimizations Department: in pmap_kremove(), update
the globally visible stats outside of the loop.

diffstat:

 sys/arch/alpha/alpha/pmap.c |  15 ++++++++++-----
 1 files changed, 10 insertions(+), 5 deletions(-)

diffs (46 lines):

diff -r 0058797b05f4 -r d6e0d6ed9292 sys/arch/alpha/alpha/pmap.c
--- a/sys/arch/alpha/alpha/pmap.c       Tue Dec 29 16:59:12 2020 +0000
+++ b/sys/arch/alpha/alpha/pmap.c       Tue Dec 29 17:16:15 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: pmap.c,v 1.273 2020/09/11 03:54:14 simonb Exp $ */
+/* $NetBSD: pmap.c,v 1.274 2020/12/29 17:16:15 thorpej Exp $ */
 
 /*-
  * Copyright (c) 1998, 1999, 2000, 2001, 2007, 2008, 2020
@@ -135,7 +135,7 @@
 
 #include <sys/cdefs.h>                 /* RCS ID & Copyright macro defns */
 
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.273 2020/09/11 03:54:14 simonb Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.274 2020/12/29 17:16:15 thorpej Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -2309,6 +2309,7 @@
        pt_entry_t *pte, opte;
        pmap_t const pmap = pmap_kernel();
        struct pmap_tlb_context tlbctx;
+       int count = 0;
 
 #ifdef DEBUG
        if (pmapdebug & (PDB_FOLLOW|PDB_ENTER))
@@ -2330,12 +2331,16 @@
                        atomic_store_relaxed(pte, PG_NV);
                        pmap_tlb_shootdown(pmap, va, opte, &tlbctx);
 
-                       /* Update stats. */
-                       PMAP_STAT_DECR(pmap->pm_stats.resident_count, 1);
-                       PMAP_STAT_DECR(pmap->pm_stats.wired_count, 1);
+                       count++;
                }
        }
 
+       /* Update stats. */
+       if (__predict_true(count != 0)) {
+               PMAP_STAT_DECR(pmap->pm_stats.resident_count, count);
+               PMAP_STAT_DECR(pmap->pm_stats.wired_count, count);
+       }
+
        pmap_tlb_shootnow(&tlbctx);
        TLB_COUNT(reason_kremove);
 }