[src/trunk]: src/sys/kern Remove some unneeded kernel_lock handling.

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

details:   https://anonhg.NetBSD.org/src/rev/b4f09554e118
branches:  trunk
changeset: 1006348:b4f09554e118
user:      ad <ad%NetBSD.org@localhost>
date:      Sun Jan 12 13:15:08 2020 +0000

description:
Remove some unneeded kernel_lock handling.

diffstat:

 sys/kern/kern_lwp.c |  14 ++++----------
 1 files changed, 4 insertions(+), 10 deletions(-)

diffs (35 lines):

diff -r 71758372748c -r b4f09554e118 sys/kern/kern_lwp.c
--- a/sys/kern/kern_lwp.c       Sun Jan 12 13:08:32 2020 +0000
+++ b/sys/kern/kern_lwp.c       Sun Jan 12 13:15:08 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_lwp.c,v 1.218 2020/01/08 17:38:42 ad Exp $        */
+/*     $NetBSD: kern_lwp.c,v 1.219 2020/01/12 13:15:08 ad Exp $        */
 
 /*-
  * Copyright (c) 2001, 2006, 2007, 2008, 2009, 2019 The NetBSD Foundation, Inc.
@@ -209,7 +209,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_lwp.c,v 1.218 2020/01/08 17:38:42 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_lwp.c,v 1.219 2020/01/12 13:15:08 ad Exp $");
 
 #include "opt_ddb.h"
 #include "opt_lockdebug.h"
@@ -1266,14 +1266,8 @@
         * the target CPU.
         */
        membar_enter();
-       if ((l->l_flag & LW_RUNNING) != 0) {
-               int count;
-               (void)count; /* XXXgcc */
-               KERNEL_UNLOCK_ALL(curlwp, &count);
-               while ((l->l_flag & LW_RUNNING) != 0 ||
-                   l->l_cpu->ci_curlwp == l)
-                       SPINLOCK_BACKOFF_HOOK;
-               KERNEL_LOCK(count, curlwp);
+       while (__predict_false((l->l_flag & LW_RUNNING) != 0)) {
+               SPINLOCK_BACKOFF_HOOK;
        }
 #endif