- Pass the priority argument from *sleep() into sleepq and down into

   sched_sleep().  This removes extra thread_lock() acquisition and
   allows the scheduler to decide what to do with the static boost.
 - Change the priority arguments to cv_* to match sleepq/msleep/etc.
   where 0 means no priority change.  Catch -1 in cv_broadcastpri() and
   convert it to 0 for now.
 - Set a flag when sleeping in a way that is compatible with swapping
   since direct priority comparisons are meaningless now.
 - Add a sysctl to ule, kern.sched.static_boost, that defaults to on which
   controls the boost behavior.  Turning it off gives better performance
   in some workloads but needs more investigation.
 - While we're modifying sleepq, change signal and broadcast to both
   return with the lock held as the lock was held on enter.

Reviewed by:	jhb, peter

1 files changed, 14 insertions, 9 deletions

diff --git a/sys/kern/kern_condvar.c b/sys/kern/kern_condvar.c
index 5d3403a..eb804ca 100644
--- a/sys/kern/kern_condvar.c
+++ b/sys/kern/kern_condvar.c
@@ -131,7 +131,7 @@ _cv_wait(struct cv *cvp, struct lock_object *lock)
 	lock_state = class->lc_unlock(lock);
 	if (class->lc_flags & LC_SLEEPABLE)
 		sleepq_lock(cvp);
-	sleepq_wait(cvp);
+	sleepq_wait(cvp, 0);
 
 #ifdef KTRACE
 	if (KTRPOINT(td, KTR_CSW))
@@ -184,7 +184,7 @@ _cv_wait_unlock(struct cv *cvp, struct lock_object *lock)
 	class->lc_unlock(lock);
 	if (class->lc_flags & LC_SLEEPABLE)
 		sleepq_lock(cvp);
-	sleepq_wait(cvp);
+	sleepq_wait(cvp, 0);
 
 #ifdef KTRACE
 	if (KTRPOINT(td, KTR_CSW))
@@ -242,7 +242,7 @@ _cv_wait_sig(struct cv *cvp, struct lock_object *lock)
 	lock_state = class->lc_unlock(lock);
 	if (class->lc_flags & LC_SLEEPABLE)
 		sleepq_lock(cvp);
-	rval = sleepq_wait_sig(cvp);
+	rval = sleepq_wait_sig(cvp, 0);
 
 #ifdef KTRACE
 	if (KTRPOINT(td, KTR_CSW))
@@ -302,7 +302,7 @@ _cv_timedwait(struct cv *cvp, struct lock_object *lock, int timo)
 	lock_state = class->lc_unlock(lock);
 	if (class->lc_flags & LC_SLEEPABLE)
 		sleepq_lock(cvp);
-	rval = sleepq_timedwait(cvp);
+	rval = sleepq_timedwait(cvp, 0);
 
 #ifdef KTRACE
 	if (KTRPOINT(td, KTR_CSW))
@@ -366,7 +366,7 @@ _cv_timedwait_sig(struct cv *cvp, struct lock_object *lock, int timo)
 	lock_state = class->lc_unlock(lock);
 	if (class->lc_flags & LC_SLEEPABLE)
 		sleepq_lock(cvp);
-	rval = sleepq_timedwait_sig(cvp);
+	rval = sleepq_timedwait_sig(cvp, 0);
 
 #ifdef KTRACE
 	if (KTRPOINT(td, KTR_CSW))
@@ -393,7 +393,7 @@ cv_signal(struct cv *cvp)
 	sleepq_lock(cvp);
 	if (cvp->cv_waiters > 0) {
 		cvp->cv_waiters--;
-		sleepq_signal(cvp, SLEEPQ_CONDVAR, -1, 0);
+		sleepq_signal(cvp, SLEEPQ_CONDVAR, 0, 0);
 	}
 	sleepq_release(cvp);
 }
@@ -405,11 +405,16 @@ cv_signal(struct cv *cvp)
 void
 cv_broadcastpri(struct cv *cvp, int pri)
 {
-
+	/*
+	 * XXX sleepq_broadcast pri argument changed from -1 meaning
+	 * no pri to 0 meaning no pri.
+	 */
+	if (pri == -1)
+		pri = 0;
 	sleepq_lock(cvp);
 	if (cvp->cv_waiters > 0) {
 		cvp->cv_waiters = 0;
 		sleepq_broadcast(cvp, SLEEPQ_CONDVAR, pri, 0);
-	} else
-		sleepq_release(cvp);
+	}
+	sleepq_release(cvp);
 }