[src/trunk]: src/sys - make lendpri/changepri similar.

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

details:   https://anonhg.NetBSD.org/src/rev/bc9afa4194fa
branches:  trunk
changeset: 770729:bc9afa4194fa
user:      yamt <yamt%NetBSD.org@localhost>
date:      Mon Oct 31 12:18:32 2011 +0000

description:
- make lendpri/changepri similar.
- make common code a subroutine.

diffstat:

 sys/kern/kern_sleepq.c |  69 +++++++++++++++++++++----------------------------
 sys/sys/lwp.h          |   7 ++++-
 2 files changed, 36 insertions(+), 40 deletions(-)

diffs (136 lines):

diff -r 57040b0c092d -r bc9afa4194fa sys/kern/kern_sleepq.c
--- a/sys/kern/kern_sleepq.c    Mon Oct 31 08:28:46 2011 +0000
+++ b/sys/kern/kern_sleepq.c    Mon Oct 31 12:18:32 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_sleepq.c,v 1.43 2011/09/03 10:28:33 christos Exp $        */
+/*     $NetBSD: kern_sleepq.c,v 1.44 2011/10/31 12:18:32 yamt Exp $    */
 
 /*-
  * Copyright (c) 2006, 2007, 2008, 2009 The NetBSD Foundation, Inc.
@@ -35,7 +35,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_sleepq.c,v 1.43 2011/09/03 10:28:33 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_sleepq.c,v 1.44 2011/10/31 12:18:32 yamt Exp $");
 
 #include <sys/param.h>
 #include <sys/kernel.h>
@@ -422,26 +422,16 @@
 }
 
 /*
- * sleepq_changepri:
+ * sleepq_reinsert:
  *
- *     Adjust the priority of an LWP residing on a sleepq.  This method
- *     will only alter the user priority; the effective priority is
- *     assumed to have been fixed at the time of insertion into the queue.
+ *     Move the possition of the lwp in the sleep queue after a possible
+ *     change of the lwp's effective priority.
  */
-void
-sleepq_changepri(lwp_t *l, pri_t pri)
+static void
+sleepq_reinsert(sleepq_t *sq, lwp_t *l)
 {
-       sleepq_t *sq = l->l_sleepq;
-       pri_t opri;
 
-       KASSERT(lwp_locked(l, NULL));
-
-       opri = lwp_eprio(l);
-       l->l_priority = pri;
-
-       if (lwp_eprio(l) == opri) {
-               return;
-       }
+       KASSERT(l->l_sleepq == sq);
        if ((l->l_syncobj->sobj_flag & SOBJ_SLEEPQ_SORTED) == 0) {
                return;
        }
@@ -459,33 +449,34 @@
        sleepq_insert(sq, l, l->l_syncobj);
 }
 
+/*
+ * sleepq_changepri:
+ *
+ *     Adjust the priority of an LWP residing on a sleepq.
+ */
+void
+sleepq_changepri(lwp_t *l, pri_t pri)
+{
+       sleepq_t *sq = l->l_sleepq;
+
+       KASSERT(lwp_locked(l, NULL));
+
+       l->l_priority = pri;
+       sleepq_reinsert(sq, l);
+}
+
+/*
+ * sleepq_changepri:
+ *
+ *     Adjust the lended priority of an LWP residing on a sleepq.
+ */
 void
 sleepq_lendpri(lwp_t *l, pri_t pri)
 {
        sleepq_t *sq = l->l_sleepq;
-       pri_t opri;
 
        KASSERT(lwp_locked(l, NULL));
 
-       opri = lwp_eprio(l);
        l->l_inheritedprio = pri;
-
-       if (lwp_eprio(l) == opri) {
-               return;
-       }
-       if ((l->l_syncobj->sobj_flag & SOBJ_SLEEPQ_SORTED) == 0) {
-               return;
-       }
-
-       /*
-        * Don't let the sleep queue become empty, even briefly.
-        * cv_signal() and cv_broadcast() inspect it without the
-        * sleep queue lock held and need to see a non-empty queue
-        * head if there are waiters.
-        */
-       if (TAILQ_FIRST(sq) == l && TAILQ_NEXT(l, l_sleepchain) == NULL) {
-               return;
-       }
-       TAILQ_REMOVE(sq, l, l_sleepchain);
-       sleepq_insert(sq, l, l->l_syncobj);
+       sleepq_reinsert(sq, l);
 }
diff -r 57040b0c092d -r bc9afa4194fa sys/sys/lwp.h
--- a/sys/sys/lwp.h     Mon Oct 31 08:28:46 2011 +0000
+++ b/sys/sys/lwp.h     Mon Oct 31 12:18:32 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: lwp.h,v 1.155 2011/08/07 21:13:06 rmind Exp $  */
+/*     $NetBSD: lwp.h,v 1.156 2011/10/31 12:18:32 yamt Exp $   */
 
 /*-
  * Copyright (c) 2001, 2006, 2007, 2008, 2009, 2010
@@ -392,7 +392,11 @@
 {
        KASSERT(mutex_owned(l->l_mutex));
 
+       if (l->l_priority == pri)
+               return;
+
        (*l->l_syncobj->sobj_changepri)(l, pri);
+       KASSERT(l->l_priority == pri);
 }
 
 static inline void
@@ -404,6 +408,7 @@
                return;
 
        (*l->l_syncobj->sobj_lendpri)(l, pri);
+       KASSERT(l->l_inheritedprio == pri);
 }
 
 static inline pri_t