--- /sys/man/3/arch
+++ /sys/man/3/arch
@@ -114,9 +114,9 @@ last address, name of device.
 Reads from
 .I irqalloc
 return the enabled interrupts, one line per
-interrupt.  Each line contains three fields separated by white space:
-the trap number, the IRQ it is assigned to, and the name of
-the device using it.
+interrupt.  Each line contains four fields separated by white space:
+the trap number, the IRQ it is assigned to, the type of interrupt,
+and the name of the device using it.
 .PP
 Reads and writes to
 .IR iob ,
--- /sys/src/9k/k10/i8259.c
+++ /sys/src/9k/k10/i8259.c
@@ -195,6 +195,7 @@ i8259irqenable(Vctl* v)
 		v->isr = i8259isr;
 	iunlock(&i8259lock);
 
+	v->type = "8259";
 	return IdtPIC+irq;
 }
 
--- /sys/src/9k/k10/io.h
+++ /sys/src/9k/k10/io.h
@@ -41,6 +41,7 @@ typedef struct Vctl {
 	void*	a;			/* argument to call it with */
 	int	tbdf;
 	char	name[KNAMELEN];		/* of driver */
+	char	*type;
 
 	int	(*isr)(int);		/* get isr bit for this irq */
 	int	(*eoi)(int);		/* eoi */
--- /sys/src/9k/k10/ioapic.c
+++ /sys/src/9k/k10/ioapic.c
@@ -297,6 +297,7 @@ ioapicintrenable(Vctl* v)
 		if(v->irq >= IdtLINT0 && v->irq <= IdtSPURIOUS){
 			if(v->irq != IdtSPURIOUS)
 				v->isr = apiceoi;
+			v->type = "lapic";
 			return v->irq;
 		}
 		else{
@@ -402,6 +403,7 @@ ioapicintrenable(Vctl* v)
 	v->isr = apicisr;
 	v->eoi = apiceoi;
 	v->vno = vecno;
+	v->type = "ioapic";
 
 	return vecno;
 }
--- /sys/src/9k/k10/trap.c
+++ /sys/src/9k/k10/trap.c
@@ -105,7 +105,7 @@ intrdisable(void* vector)
 static long
 irqallocread(Chan*, void *vbuf, long n, vlong offset)
 {
-	char *buf, *p, str[2*(11+1)+KNAMELEN+1+1];
+	char *buf, *p, str[2*(11+1)+(8+1)+KNAMELEN+1+1];
 	int ns, vno;
 	long oldn;
 	Vctl *v;
@@ -117,7 +117,8 @@ irqallocread(Chan*, void *vbuf, long n, vlong offset)
 	buf = vbuf;
 	for(vno=0; vno<nelem(vctl); vno++){
 		for(v=vctl[vno]; v; v=v->next){
-			ns = snprint(str, sizeof str, "%11d %11d %.*s\n", vno, v->irq, KNAMELEN, v->name);
+			ns = snprint(str, sizeof str, "%11d %11d %-*.*s %.*s\n",
+				vno, v->irq, 8, 8, v->type, KNAMELEN, v->name);
 			if(ns <= offset)	/* if do not want this, skip entry */
 				offset -= ns;
 			else{
@@ -149,6 +150,7 @@ trapenable(int vno, void (*f)(Ureg*, void*), void* a, char *name)
 	if(vno < 0 || vno >= 256)
 		panic("trapenable: vno %d", vno);
 	v = malloc(sizeof(Vctl));
+	v->type = "trap";
 	v->tbdf = BUSUNKNOWN;
 	v->f = f;
 	v->a = a;