[src/trunk]: src/sys kpause(): is only awoken via timeout or signal, so use S...

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

details:   https://anonhg.NetBSD.org/src/rev/d30d7015af0d
branches:  trunk
changeset: 969587:d30d7015af0d
user:      ad <ad%NetBSD.org@localhost>
date:      Sun Feb 23 16:27:09 2020 +0000

description:
kpause(): is only awoken via timeout or signal, so use SOBJ_SLEEPQ_NULL like
_lwp_park() does, and dispense with the hashed sleepq & lock.

diffstat:

 sys/kern/kern_synch.c |  20 +++++++++++++-------
 sys/sys/syncobj.h     |   3 ++-
 2 files changed, 15 insertions(+), 8 deletions(-)

diffs (72 lines):

diff -r 1d0e5821fbe3 -r d30d7015af0d sys/kern/kern_synch.c
--- a/sys/kern/kern_synch.c     Sun Feb 23 16:04:58 2020 +0000
+++ b/sys/kern/kern_synch.c     Sun Feb 23 16:27:09 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_synch.c,v 1.341 2020/02/23 15:46:41 ad Exp $      */
+/*     $NetBSD: kern_synch.c,v 1.342 2020/02/23 16:27:09 ad Exp $      */
 
 /*-
  * Copyright (c) 1999, 2000, 2004, 2006, 2007, 2008, 2009, 2019, 2020
@@ -69,7 +69,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_synch.c,v 1.341 2020/02/23 15:46:41 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_synch.c,v 1.342 2020/02/23 16:27:09 ad Exp $");
 
 #include "opt_kstack.h"
 #include "opt_dtrace.h"
@@ -122,6 +122,14 @@
        .sobj_owner     = syncobj_noowner,
 };
 
+syncobj_t kpause_syncobj = {
+       .sobj_flag      = SOBJ_SLEEPQ_NULL,
+       .sobj_unsleep   = sleepq_unsleep,
+       .sobj_changepri = sleepq_changepri,
+       .sobj_lendpri   = sleepq_lendpri,
+       .sobj_owner     = syncobj_noowner,
+};
+
 /* "Lightning bolt": once a second sleep address. */
 kcondvar_t             lbolt                   __cacheline_aligned;
 
@@ -258,8 +266,6 @@
 kpause(const char *wmesg, bool intr, int timo, kmutex_t *mtx)
 {
        struct lwp *l = curlwp;
-       kmutex_t *mp;
-       sleepq_t *sq;
        int error;
 
        KASSERT(!(timo == 0 && intr == false));
@@ -270,9 +276,9 @@
        if (mtx != NULL)
                mutex_exit(mtx);
        l->l_kpriority = true;
-       sq = sleeptab_lookup(&sleeptab, l, &mp);
-       sleepq_enter(sq, l, mp);
-       sleepq_enqueue(sq, l, wmesg, &sleep_syncobj);
+       lwp_lock(l);
+       KERNEL_UNLOCK_ALL(NULL, &l->l_biglocks);
+       sleepq_enqueue(NULL, l, wmesg, &kpause_syncobj);
        error = sleepq_block(timo, intr);
        if (mtx != NULL)
                mutex_enter(mtx);
diff -r 1d0e5821fbe3 -r d30d7015af0d sys/sys/syncobj.h
--- a/sys/sys/syncobj.h Sun Feb 23 16:04:58 2020 +0000
+++ b/sys/sys/syncobj.h Sun Feb 23 16:27:09 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: syncobj.h,v 1.10 2020/02/15 17:09:24 ad Exp $  */
+/*     $NetBSD: syncobj.h,v 1.11 2020/02/23 16:27:09 ad Exp $  */
 
 /*-
  * Copyright (c) 2007, 2008, 2020 The NetBSD Foundation, Inc.
@@ -59,6 +59,7 @@
 extern syncobj_t       cv_syncobj;
 extern syncobj_t       lwp_park_syncobj;
 extern syncobj_t       mutex_syncobj;
+extern syncobj_t       kpause_syncobj;
 extern syncobj_t       rw_syncobj;
 extern syncobj_t       sched_syncobj;
 extern syncobj_t       select_syncobj;