PERFORCE change 52643 for review

[Julian Elischer]

http://perforce.freebsd.org/chv.cgi?CH=52643

Change 52643 by julian at julian_ref on 2004/05/10 16:05:05

	try not crash in boot.

Affected files ...

.. //depot/projects/nsched/sys/i386/i386/mp_machdep.c#2 edit
.. //depot/projects/nsched/sys/kern/kern_exit.c#5 edit
.. //depot/projects/nsched/sys/kern/kern_thread.c#12 edit
.. //depot/projects/nsched/sys/kern/sched_4bsd.c#7 edit

Differences ...

==== //depot/projects/nsched/sys/i386/i386/mp_machdep.c#2 (text+ko) ====

@@ -550,7 +550,7 @@
 	binuptime(PCPU_PTR(switchtime));
 	PCPU_SET(switchticks, ticks);
 
-	cpu_throw(NULL, choosethread());	/* doesn't return */
+	cpu_throw(NULL, choosethread(SW_VOL));	/* doesn't return */
 
 	panic("scheduler returned us to %s", __func__);
 	/* NOTREACHED */

==== //depot/projects/nsched/sys/kern/kern_exit.c#5 (text+ko) ====

@@ -489,15 +489,6 @@
 	 */
 	cpu_exit(td);
 
-	/*
-	 * Release this thread's reference to the ucred.  The actual proc
-	 * reference will stay around until the proc is harvested by
-	 * wait().  XXX maybe this should be done there too.
-	 */
-	crfree(td->td_ucred);
-	td->td_ucred = NULL;
-
-
 	PROC_LOCK(p);
 	PROC_LOCK(p->p_pptr);
 	sx_xunlock(&proctree_lock);
@@ -530,7 +521,7 @@
 	 * Allow the scheduler to adjust the priority of the
 	 * parent when a process is exiting.
 	 */
-	if (p->p_pid != 1) 
+	if (p->p_pptr != initproc) 
 		sched_exit(p->p_pptr, td);
 
 	/*
@@ -683,6 +674,8 @@
 
 			/*
 			 * do any thread-system specific cleanups
+			 * like freeing the thread's ucred,
+			 * and any spare threads, etc.
 			 */
 			thread_wait(p);
 
@@ -697,8 +690,6 @@
 #ifdef MAC
 			mac_destroy_proc(p);
 #endif
-			KASSERT(FIRST_THREAD_IN_PROC(p),
-			    ("kern_wait: no residual thread!"));
 			uma_zfree(proc_zone, p);
 			sx_xlock(&allproc_lock);
 			nprocs--;

==== //depot/projects/nsched/sys/kern/kern_thread.c#12 (text+ko) ====

@@ -645,6 +645,10 @@
 	KASSERT((p->p_numthreads == 1), ("Multiple threads in wait1()"));
 	KASSERT((p->p_numksegrps == 1), ("Multiple ksegrps in wait1()"));
 	FOREACH_THREAD_IN_PROC(p, td) {
+		if (td->td_ucred) {
+			crfree(td->td_ucred);
+			td->td_ucred = NULL;
+		}
 		if (td->td_standin != NULL) {
 			thread_free(td->td_standin);
 			td->td_standin = NULL;

==== //depot/projects/nsched/sys/kern/sched_4bsd.c#7 (text+ko) ====

@@ -1202,11 +1202,11 @@
 		TAILQ_REMOVE(&kg->kg_iq, ke, ke_kgrlist);
 		kg->kg_idle_kses--;
 	}
-	if (--kg->kg_kses == 0)
-		ksegrp_unlink(kg);
 	/*
 	 * Aggregate stats from the KSE
+	 * ## none yet ##
 	 */
+
 	kse_stash(ke);
 }
 
@@ -1300,12 +1300,14 @@
 
 /* 
  * Whenever we have idle KSEs and there are too many for the concurrancy,
- * then free as many as we can.
+ * then free as many as we can. Don't free too many if we have threads
+ * to run/kill.
  */
-#define REDUCE_KSES(skg) 					\
+#define REDUCE_KSES(kg, skg) 					\
 do {								\
 	while ((skg->skg_concurrancy < skg->skg_kses) &&	\
-    	(skg->skg_idle_kses > 0)) {				\
+    	(skg->skg_idle_kses > 0) &&				\
+	(skg->skg_kses > kg->kg_numthreads)) {			\
 		kse_unlink(TAILQ_FIRST(&skg->skg_iq));		\
 	}							\
 } while (0)
@@ -1318,7 +1320,7 @@
 
 	skg = kg->kg_sched;
 	skg->skg_concurrancy = concurrancy;
-	REDUCE_KSES(skg);
+	REDUCE_KSES(kg, skg);
 	while (skg->skg_kses < skg->skg_concurrancy) {
 		newke = kse_alloc();
 		bzero(&newke->ke_startzero, RANGEOF(struct kse,
@@ -1554,7 +1556,7 @@
 	TAILQ_INSERT_TAIL(&kg->kg_iq, ke, ke_kgrlist);
 	kg->kg_idle_kses++;
 	CTR1(KTR_RUNQ, "kse_reassign: ke%p on idle queue", ke);
-	REDUCE_KSES(kg->kg_sched); /* if we are closing down discard it */
+	REDUCE_KSES(kg, kg->kg_sched); /* if we are closing down discard it */
 	return;
 }