remove the union.  just use Mpl pl.

Reference: /n/atom/patch/applied/nixmcscleanup
Date: Sun Jun  8 10:17:50 CES 2014
Signed-off-by: quanstro@quanstro.net

--- /sys/src/nix/port/mcslock.c	Sun Jun  8 10:17:37 2014
+++ /sys/src/nix/port/mcslock.c	Sun Jun  8 10:17:37 2014
@@ -21,7 +21,7 @@
 		ql->locked = 1;
 		sfence();	/* ensure reader sees updated value */
 		pred->next = ql;
-		while(monmwait32(&ql->locked, 1) == 1)
+		while(monmwait(&ql->locked, 1) == 1)
 			{}
 	}
 }
@@ -146,14 +146,14 @@
 ilock(Lock *l)
 {
 	uintptr pc;
-	Mreg s;
+	Mpl pl;
 	LockEntry *ql;
 
 	pc = getcallerpc(&l);
-	s = splhi();
+	pl = splhi();
 	ql = allocle(l, pc);
 	ql->isilock = 1;
-	ql->sr = s;
+	ql->pl = pl;
 	/* the old taslock code would splx(s) to allow interrupts while waiting (if not nested) */
 	mcslock(l, ql);
 	l->e = ql;
@@ -166,7 +166,7 @@
 void
 iunlock(Lock *l)
 {
-	Mreg s;
+	Mpl pl;
 	LockEntry *ql;
 
 	if(islo())
@@ -175,16 +175,16 @@
 	if(!ql->isilock)
 		panic("iunlock of lock: pc %#p\n", getcallerpc(&l));
 	if(ql->m != m){
-		panic("iunlock by cpu%d, locked by cpu%d: pc %#p\n",
+		panic("iunlock by mach%d, locked by mach%d: pc %#p\n",
 			m->machno, ql->m->machno, getcallerpc(&l));
 	}
 	mcsunlock(l, ql);
-	s = ql->sr;
+	pl = ql->pl;
 	ql->used = nil;
 	m->ilockdepth--;
 	if(up != nil)
 		up->lastilock = nil;
-	splx(s);
+	splx(pl);
 }
 
 int
--- /sys/src/nix/port/portdat.h	Sun Jun  8 10:17:37 2014
+++ /sys/src/nix/port/portdat.h	Sun Jun  8 10:17:37 2014
@@ -110,10 +110,7 @@
 	uint	locked;
 	Lock*	used;
 	int	isilock;
-	union {					/* GAK */
-		Mpl	pl;
-		Mreg	sr;
-	};
+	Mpl	pl;
 	/* for debugging */
 	uintptr	pc;
 	Proc*	p;
@@ -705,7 +702,8 @@
 	uint	delayedscheds;	/* statistics */
 	uint	skipscheds;
 	uint	preempts;
-	uint	balancetime;
+	uint	loop;
+	ulong	balancetime;
 	Schedq	runq[Nrq];
 	uint	runvec;
 	int	nmach;		/* # of cores with this color */
@@ -1082,6 +1080,7 @@
 extern	char*	statename[];
 extern	Lockstats lockstats;
 extern	QLockstats qlockstats;
+extern	Waitstats waitstats;
 extern	struct {
 	char*	n;
 	void (*f)(Ar0*, va_list);