From 0a6f3cd428b509bd0db26c5d211340371a3e7c02 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Mon, 30 Oct 1995 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1995-10-30

---
 carrera/dat.h  |  1 +
 pc/dat.h       |  1 +
 port/devcons.c |  3 +++
 port/portfns.h |  2 ++
 port/proc.c    | 46 +++++++++++++++++++++++++++++++++-------------
 port/taslock.c | 26 +++++++++++++++++++++-----
 power/dat.h    |  1 +
 7 files changed, 62 insertions(+), 18 deletions(-)

diff --git a/carrera/dat.h b/carrera/dat.h
index 8750f7c38ac11e185acc9d3b0decee6f8e35476c..e4dffff10d14c50ece09aaf70e20da9462bb8885 100644
--- a/carrera/dat.h
+++ b/carrera/dat.h
@@ -26,6 +26,7 @@ struct Lock
 	ulong	key;			/* semaphore (non-zero = locked) */
 	ulong	sr;
 	ulong	pc;
+	ulong	pid;
 };
 
 struct Label
diff --git a/pc/dat.h b/pc/dat.h
index 1cadf39903c7f8331403f0230c1db28c472a5255..5a3379778a249b9247dcb3cd7a669d122f7f5f84 100644
--- a/pc/dat.h
+++ b/pc/dat.h
@@ -29,6 +29,7 @@ struct Lock
 	ulong	key;
 	ulong	sr;
 	ulong	pc;
+	ulong	pid;
 };
 
 struct Label
diff --git a/port/devcons.c b/port/devcons.c
index 5d4c1bab01a68a8f6151cf440a36969d3b1181e6..10556957c9e7b6160b03fd0c30db06d3c5e4deb3 100644
--- a/port/devcons.c
+++ b/port/devcons.c
@@ -217,6 +217,9 @@ echo(Rune r, char *buf, int n)
 		case 'p':
 			procdump();
 			return;
+		case 'q':
+			scheddump();
+			break;
 		case 'k':
 			if(!cpuserver)
 				killbig();
diff --git a/port/portfns.h b/port/portfns.h
index 6bd92baaa292197886598840cd3cb4db4d020f53..154537cd50c597d006722a906109c429f83c47fa 100644
--- a/port/portfns.h
+++ b/port/portfns.h
@@ -62,6 +62,7 @@ Chan*		devopen(Chan*, int, Dirtab*, int, Devgen*);
 void		devstat(Chan*, char*, Dirtab*, int, Devgen*);
 int		devwalk(Chan*, char*, Dirtab*, int, Devgen*);
 Chan*		domount(Chan*);
+void		dumpaproc(Proc*);
 void		dumpqueues(void);
 void		dumpregs(Ureg*);
 void		dumpstack(void);
@@ -237,6 +238,7 @@ void		sccclock(void);
 int		sccintr(void);
 void		sccsetup(void*, ulong, int);
 void		sched(void);
+void		scheddump(void);
 void		schedinit(void);
 int		screenbits(void);
 #define		scsialloc(n)	mallocz((n)+512, 0)
diff --git a/port/proc.c b/port/proc.c
index 13c8e8c5ea8de8888a6c4882bc0420407c713116..cbfcac23aafedcbd84c491a0a50765dbfec945fc 100644
--- a/port/proc.c
+++ b/port/proc.c
@@ -784,14 +784,32 @@ proctab(int i)
 	return &procalloc.arena[i];
 }
 
+void
+dumpaproc(Proc *p)
+{
+	ulong bss;
+	char *s;
+
+	if(p == 0)
+		return;
+
+	bss = 0;
+	if(p->seg[BSEG])
+		bss = p->seg[BSEG]->top;
+
+	s = p->psstate;
+	if(s == 0)
+		s = "kproc";
+	print("%3d:%10s pc %8lux dbgpc %8lux  %8s (%s) ut %ld st %ld bss %lux\n",
+		p->pid, p->text, p->pc, dbgpc(p),  s, statename[p->state],
+		p->time[0], p->time[1], bss, p->priority);
+}
+
 void
 procdump(void)
 {
 	int i;
-	char *s;
 	Proc *p;
-	ulong bss;
-	Schedq *rq;
 
 	if(up)
 		print("up %d\n", up->pid);
@@ -801,17 +819,18 @@ procdump(void)
 		p = &procalloc.arena[i];
 		if(p->state == Dead)
 			continue;
-		bss = 0;
-		if(p->seg[BSEG])
-			bss = p->seg[BSEG]->top;
-
-		s = p->psstate;
-		if(s == 0)
-			s = "kproc";
-		print("%3d:%10s pc %8lux dbgpc %8lux  %8s (%s) ut %ld st %ld bss %lux\n",
-			p->pid, p->text, p->pc, dbgpc(p),  s, statename[p->state],
-			p->time[0], p->time[1], bss);
+
+		dumpaproc(p);
+		delay(150);
 	}
+}
+
+void
+scheddump(void)
+{
+	Proc *p;
+	Schedq *rq;
+
 	for(rq = &runq[Nrq-1]; rq >= runq; rq--){
 		if(rq->head == 0)
 			continue;
@@ -820,6 +839,7 @@ procdump(void)
 			print(" %d(%d, %d)", p->pid, m->ticks - p->readytime,
 				m->ticks - p->movetime);
 		print("\n");
+		delay(150);
 	}
 	print("nrdy %d\n", nrdy);
 }
diff --git a/port/taslock.c b/port/taslock.c
index 553e7ecffb4783ac1f0ab8694e4b0610e6a5dc3b..f0b2598273fca18fb949c62cf115fa737af456e7 100644
--- a/port/taslock.c
+++ b/port/taslock.c
@@ -5,27 +5,39 @@
 #include "fns.h"
 #include "../port/error.h"
 
+void
+lockloop(Lock *l, ulong pc)
+{
+	print("lock loop key 0x%lux pc 0x%lux held by pc 0x%lux proc %d\n",
+		l->key, pc, l->pc, l->pid);
+	dumpaproc(up);
+}
+
 void
 lock(Lock *l)
 {
 	int i;
-	ulong pc;
+	ulong pc, pid;
 
 	pc = getcallerpc(l);
+	pid = up ? up->pid : 0;
 
 	if(tas(&l->key) == 0){
 		l->pc = pc;
+		l->pid = pid;
 		return;
 	}
 
 	for(;;){
 		i = 0;
 		while(l->key)
-			if(i++ > 100000000)
-				panic("lock loop key 0x%lux pc 0x%lux held by pc 0x%lux pl 0x%lux\n",
-					l->key, pc, l->pc, splhi());
+			if(i++ > 100000000){
+				i = 0;
+				lockloop(l, pc);
+			}
 		if(tas(&l->key) == 0){
 			l->pc = pc;
+			l->pid = pid;
 			return;
 		}
 	}
@@ -35,14 +47,16 @@ void
 ilock(Lock *l)
 {
 	ulong x;
-	ulong pc;
+	ulong pc, pid;
 
 	pc = getcallerpc(l);
+	pid = up ? up->pid : 0;
 
 	x = splhi();
 	if(tas(&l->key) == 0){
 		l->sr = x;
 		l->pc = pc;
+		l->pid = pid;
 		return;
 	}
 
@@ -52,6 +66,7 @@ ilock(Lock *l)
 		if(tas(&l->key) == 0){
 			l->sr = x;
 			l->pc = pc;
+			l->pid = pid;
 			return;
 		}
 	}
@@ -64,6 +79,7 @@ canlock(Lock *l)
 		return 0;
 
 	l->pc = getcallerpc(l);
+	l->pid = up ? up->pid : 0;
 	return 1;
 }
 
diff --git a/power/dat.h b/power/dat.h
index 88c11a2acef936894bceab4e90fd690204b821a5..1f00ead903a08150e38a5d8012e9b49a58708cc5 100644
--- a/power/dat.h
+++ b/power/dat.h
@@ -25,6 +25,7 @@ struct Lock
 	int	val;
 	ulong	pc;
 	ulong	sr;
+	ulong	pid;
 };
 
 struct Label