[src/trunk]: src/sys/kern Don't try to kpreempt a CPU hog unless __HAVE_PREEM...

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

details:   https://anonhg.NetBSD.org/src/rev/a7b530ab5513
branches:  trunk
changeset: 465589:a7b530ab5513
user:      ad <ad%NetBSD.org@localhost>
date:      Fri Nov 29 18:29:45 2019 +0000

description:
Don't try to kpreempt a CPU hog unless __HAVE_PREEMPTION (oops).

diffstat:

 sys/kern/sched_4bsd.c |  12 ++++++++++--
 1 files changed, 10 insertions(+), 2 deletions(-)

diffs (44 lines):

diff -r 73e952649739 -r a7b530ab5513 sys/kern/sched_4bsd.c
--- a/sys/kern/sched_4bsd.c     Fri Nov 29 18:27:32 2019 +0000
+++ b/sys/kern/sched_4bsd.c     Fri Nov 29 18:29:45 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: sched_4bsd.c,v 1.37 2019/11/23 22:35:08 ad Exp $       */
+/*     $NetBSD: sched_4bsd.c,v 1.38 2019/11/29 18:29:45 ad Exp $       */
 
 /*
  * Copyright (c) 1999, 2000, 2004, 2006, 2007, 2008, 2019
@@ -69,7 +69,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sched_4bsd.c,v 1.37 2019/11/23 22:35:08 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sched_4bsd.c,v 1.38 2019/11/29 18:29:45 ad Exp $");
 
 #include "opt_ddb.h"
 #include "opt_lockdebug.h"
@@ -128,8 +128,12 @@
                break;
        case SCHED_RR:
                /* Force it into mi_switch() to look for other jobs to run. */
+#ifdef __HAVE_PREEMPTION
                atomic_or_uint(&l->l_dopreempt, DOPREEMPT_ACTIVE);
                cpu_need_resched(ci, l, RESCHED_KPREEMPT);
+#else
+               cpu_need_resched(ci, l, RESCHED_UPREEMPT);
+#endif
                break;
        default:
                if (spc->spc_flags & SPCF_SHOULDYIELD) {
@@ -138,8 +142,12 @@
                         * due to buggy or inefficient code.  Force a
                         * kernel preemption.
                         */
+#ifdef __HAVE_PREEMPTION
                        atomic_or_uint(&l->l_dopreempt, DOPREEMPT_ACTIVE);
                        cpu_need_resched(ci, l, RESCHED_KPREEMPT);
+#else
+                       cpu_need_resched(ci, l, RESCHED_UPREEMPT);
+#endif
                } else if (spc->spc_flags & SPCF_SEENRR) {
                        /*
                         * The process has already been through a roundrobin