[src/trunk]: src/sys/kern Sprinkle cold conditionals to make tc_ticktock befo...

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

details:   https://anonhg.NetBSD.org/src/rev/8a4f332c43a6
branches:  trunk
changeset: 323790:8a4f332c43a6
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sat Jun 30 22:47:51 2018 +0000

description:
Sprinkle cold conditionals to make tc_ticktock before inittimecounter.

Enables Xen to boot again.

XXX Maybe we should have a tc_ticktock_cold instead or something so we
don't have to reach this far into the call graph.

diffstat:

 sys/kern/kern_ntptime.c |   6 +++---
 sys/kern/kern_tc.c      |  14 ++++++++------
 2 files changed, 11 insertions(+), 9 deletions(-)

diffs (83 lines):

diff -r f2d7a3e67ddb -r 8a4f332c43a6 sys/kern/kern_ntptime.c
--- a/sys/kern/kern_ntptime.c   Sat Jun 30 20:53:30 2018 +0000
+++ b/sys/kern/kern_ntptime.c   Sat Jun 30 22:47:51 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_ntptime.c,v 1.57 2015/11/23 23:45:44 joerg Exp $  */
+/*     $NetBSD: kern_ntptime.c,v 1.58 2018/06/30 22:47:51 riastradh Exp $      */
 
 /*-
  * Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -60,7 +60,7 @@
 
 #include <sys/cdefs.h>
 /* __FBSDID("$FreeBSD: src/sys/kern/kern_ntptime.c,v 1.59 2005/05/28 14:34:41 rwatson Exp $"); */
-__KERNEL_RCSID(0, "$NetBSD: kern_ntptime.c,v 1.57 2015/11/23 23:45:44 joerg Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_ntptime.c,v 1.58 2018/06/30 22:47:51 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ntp.h"
@@ -418,7 +418,7 @@
        int tickrate;
        l_fp ftemp;             /* 32/64-bit temporary */
 
-       KASSERT(mutex_owned(&timecounter_lock));
+       KASSERT(__predict_false(cold) || mutex_owned(&timecounter_lock));
 
 #ifdef NTP
 
diff -r f2d7a3e67ddb -r 8a4f332c43a6 sys/kern/kern_tc.c
--- a/sys/kern/kern_tc.c        Sat Jun 30 20:53:30 2018 +0000
+++ b/sys/kern/kern_tc.c        Sat Jun 30 22:47:51 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_tc.c,v 1.49 2018/02/13 09:26:17 maxv Exp $ */
+/* $NetBSD: kern_tc.c,v 1.50 2018/06/30 22:47:51 riastradh Exp $ */
 
 /*-
  * Copyright (c) 2008, 2009 The NetBSD Foundation, Inc.
@@ -40,7 +40,7 @@
 
 #include <sys/cdefs.h>
 /* __FBSDID("$FreeBSD: src/sys/kern/kern_tc.c,v 1.166 2005/09/19 22:16:31 andre Exp $"); */
-__KERNEL_RCSID(0, "$NetBSD: kern_tc.c,v 1.49 2018/02/13 09:26:17 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_tc.c,v 1.50 2018/06/30 22:47:51 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ntp.h"
@@ -572,7 +572,7 @@
 {
        struct timecounter *best, *tc;
 
-       KASSERT(mutex_owned(&timecounter_lock));
+       KASSERT(__predict_false(cold) || mutex_owned(&timecounter_lock));
 
        for (best = tc = timecounters; tc != NULL; tc = tc->tc_next) {
                if (tc->tc_quality > best->tc_quality)
@@ -731,7 +731,7 @@
        int i, s_update;
        time_t t;
 
-       KASSERT(mutex_owned(&timecounter_lock));
+       KASSERT(__predict_false(cold) || mutex_owned(&timecounter_lock));
 
        s_update = 0;
 
@@ -1308,7 +1308,8 @@
        if (++count < tc_tick)
                return;
        count = 0;
-       mutex_spin_enter(&timecounter_lock);
+       if (__predict_true(!cold))
+               mutex_spin_enter(&timecounter_lock);
        if (timecounter_bad != 0) {
                /* An existing timecounter has gone bad, pick a new one. */
                (void)atomic_swap_uint(&timecounter_bad, 0);
@@ -1317,7 +1318,8 @@
                }
        }
        tc_windup();
-       mutex_spin_exit(&timecounter_lock);
+       if (__predict_true(!cold))
+               mutex_spin_exit(&timecounter_lock);
 }
 
 void