From 462a175606b9da45c0a1167c7c86b32fabb2d80b Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Mon, 9 Oct 1995 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1995-10-09

---
 carrera/dat.h  |  1 +
 pc/dat.h       |  1 +
 port/proc.c    |  7 ++++++-
 port/taslock.c | 24 +++++++++++++++++++++---
 4 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/carrera/dat.h b/carrera/dat.h
index 74f3039c66476f725b5568323910c56f26895854..8750f7c38ac11e185acc9d3b0decee6f8e35476c 100644
--- a/carrera/dat.h
+++ b/carrera/dat.h
@@ -25,6 +25,7 @@ struct Lock
 {
 	ulong	key;			/* semaphore (non-zero = locked) */
 	ulong	sr;
+	ulong	pc;
 };
 
 struct Label
diff --git a/pc/dat.h b/pc/dat.h
index 71a274c0e8100996c36e04dc4992ca33f328e349..1cadf39903c7f8331403f0230c1db28c472a5255 100644
--- a/pc/dat.h
+++ b/pc/dat.h
@@ -28,6 +28,7 @@ struct Lock
 {
 	ulong	key;
 	ulong	sr;
+	ulong	pc;
 };
 
 struct Label
diff --git a/port/proc.c b/port/proc.c
index d387e1aaa1bda50e6f597d705a9d34226635afc9..77b043020370cb32bebbce7728626cad7cf21e26 100644
--- a/port/proc.c
+++ b/port/proc.c
@@ -793,6 +793,10 @@ procdump(void)
 	ulong bss;
 	Schedq *rq;
 
+	if(up)
+		print("up %d\n", up->pid);
+	else
+		print("no current process\n");
 	for(i=0; i<conf.nproc; i++) {
 		p = &procalloc.arena[i];
 		if(p->state == Dead)
@@ -813,7 +817,8 @@ procdump(void)
 			continue;
 		print("rq%d:", rq-runq);
 		for(p = rq->head; p; p = p->rnext)
-			print(" %d(%d)", p->pid, m->ticks - p->readytime);
+			print(" %d(%d, %d)", p->pid, m->ticks - p->readytime,
+				m->ticks - p->movetime);
 		print("\n");
 	}
 	print("nrdy %d\n", nrdy);
diff --git a/port/taslock.c b/port/taslock.c
index 0e1bd45d6d83eb749e8f3f975e403f603323e2ef..84b22821b86b258a8a3ca2ea07feed314a58a7f2 100644
--- a/port/taslock.c
+++ b/port/taslock.c
@@ -8,14 +8,26 @@
 void
 lock(Lock *l)
 {
-	if(tas(&l->key) == 0)
+	int i;
+	ulong pc;
+
+	pc = getcallerpc(l);
+
+	if(tas(&l->key) == 0){
+		l->pc = pc;
 		return;
+	}
 
 	for(;;){
+		i = 0;
 		while(l->key)
-			;
-		if(tas(&l->key) == 0)
+			if(i++ > 10000000)
+				panic("lock loop key 0x%lux pc 0x%lux held by pc 0x%lux\n",
+					l->key, getcallerpc(l), l->pc);
+		if(tas(&l->key) == 0){
+			l->pc = pc;
 			return;
+		}
 	}
 }
 
@@ -23,10 +35,14 @@ void
 ilock(Lock *l)
 {
 	ulong x;
+	ulong pc;
+
+	pc = getcallerpc(l);
 
 	x = splhi();
 	if(tas(&l->key) == 0){
 		l->sr = x;
+		l->pc = pc;
 		return;
 	}
 
@@ -35,6 +51,7 @@ ilock(Lock *l)
 			;
 		if(tas(&l->key) == 0){
 			l->sr = x;
+			l->pc = pc;
 			return;
 		}
 	}
@@ -46,6 +63,7 @@ canlock(Lock *l)
 	if(tas(&l->key))
 		return 0;
 
+	l->pc = getcallerpc(l);
 	return 1;
 }