Switch the sleep/wakeup and condition variable implementations to use the

sleep queue interface:
- Sleep queues attempt to merge some of the benefits of both sleep queues
  and condition variables.  Having sleep qeueus in a hash table avoids
  having to allocate a queue head for each wait channel.  Thus, struct cv
  has shrunk down to just a single char * pointer now.  However, the
  hash table does not hold threads directly, but queue heads.  This means
  that once you have located a queue in the hash bucket, you no longer have
  to walk the rest of the hash chain looking for threads.  Instead, you have
  a list of all the threads sleeping on that wait channel.
- Outside of the sleepq code and the sleep/cv code the kernel no longer
  differentiates between cv's and sleep/wakeup.  For example, calls to
  abortsleep() and cv_abort() are replaced with a call to sleepq_abort().
  Thus, the TDF_CVWAITQ flag is removed.  Also, calls to unsleep() and
  cv_waitq_remove() have been replaced with calls to sleepq_remove().
- The sched_sleep() function no longer accepts a priority argument as
  sleep's no longer inherently bump the priority.  Instead, this is soley
  a propery of msleep() which explicitly calls sched_prio() before
  blocking.
- The TDF_ONSLEEPQ flag has been dropped as it was never used.  The
  associated TDF_SET_ONSLEEPQ and TDF_CLR_ON_SLEEPQ macros have also been
  dropped and replaced with a single explicit clearing of td_wchan.
  TD_SET_ONSLEEPQ() would really have only made sense if it had taken
  the wait channel and message as arguments anyway.  Now that that only
  happens in one place, a macro would be overkill.

1 files changed, 3 insertions, 8 deletions

diff --git a/sys/kern/sys_generic.c b/sys/kern/sys_generic.c
index 7ba4f26..8154e59 100644
--- a/sys/kern/sys_generic.c
+++ b/sys/kern/sys_generic.c
@@ -60,6 +60,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/poll.h>
 #include <sys/resourcevar.h>
 #include <sys/selinfo.h>
+#include <sys/sleepqueue.h>
 #include <sys/syscallsubr.h>
 #include <sys/sysctl.h>
 #include <sys/sysent.h>
@@ -1212,15 +1213,9 @@ doselwakeup(sip, pri)
 	TAILQ_REMOVE(&td->td_selq, sip, si_thrlist);
 	sip->si_thread = NULL;
 	mtx_lock_spin(&sched_lock);
-	if (td->td_wchan == &selwait) {
-		cv_waitq_remove(td);
-		TD_CLR_SLEEPING(td);
-		if (pri >= PRI_MIN && pri <= PRI_MAX && td->td_priority > pri)
-			td->td_priority = pri;
-		setrunnable(td);
-	} else
-		td->td_flags &= ~TDF_SELECT;
+	td->td_flags &= ~TDF_SELECT;
 	mtx_unlock_spin(&sched_lock);
+	sleepq_remove(td, &selwait);
 	mtx_unlock(&sellock);
 }