Changes to exit handling.

cpu_exit no longer frees the vmspace and u-area. This is now handled by a
separate kernel thread "reaper". This is to avoid sleeping locks in the
critical path of cpu_exit where we're not allowed to sleep.

From NetBSD

35 files changed, 249 insertions, 206 deletions

diff --git a/sys/arch/alpha/alpha/locore.s b/sys/arch/alpha/alpha/locore.s
index 5567c507053..3ec60e37fec 100644
--- a/sys/arch/alpha/alpha/locore.s
+++ b/sys/arch/alpha/alpha/locore.s
@@ -1,4 +1,4 @@
-/*	$OpenBSD: locore.s,v 1.11 1999/11/13 21:33:44 deraadt Exp $	*/
+/*	$OpenBSD: locore.s,v 1.12 2000/06/05 11:02:54 art Exp $	*/
 /*	$NetBSD: locore.s,v 1.27 1996/12/03 19:54:16 cgd Exp $	*/
 
 /*
@@ -833,11 +833,9 @@ LEAF(switch_exit, 1)
 	 * the saved regs.
 	 */
 
-	/* blow away the old user struct */
-	ldq	a0, kernel_map
-	ldq	a1, P_ADDR(s2)
-	ldiq	a2, (UPAGES * NBPG)
-	CALL(kmem_free)
+	/* Schedule the vmspace and stack to be freed. */
+	mov     s2, a0
+	CALL(exit2)
 
 	/* and jump into the middle of cpu_switch. */
 #ifdef NEW_PMAP
diff --git a/sys/arch/alpha/alpha/vm_machdep.c b/sys/arch/alpha/alpha/vm_machdep.c
index 9009bc0cbe2..fe182b2fe0e 100644
--- a/sys/arch/alpha/alpha/vm_machdep.c
+++ b/sys/arch/alpha/alpha/vm_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vm_machdep.c,v 1.12 1999/09/14 11:41:18 kstailey Exp $	*/
+/*	$OpenBSD: vm_machdep.c,v 1.13 2000/06/05 11:02:55 art Exp $	*/
 /*	$NetBSD: vm_machdep.c,v 1.21 1996/11/13 21:13:15 cgd Exp $	*/
 
 /*
@@ -116,8 +116,6 @@ cpu_exit(p)
 	if (p == fpcurproc)
 		fpcurproc = NULL;
 
-	vmspace_free(p->p_vmspace);
-
 	(void) splhigh();
 	switch_exit(p);
 	/* NOTREACHED */
diff --git a/sys/arch/amiga/amiga/locore.s b/sys/arch/amiga/amiga/locore.s
index 5db4275ae7c..dd604cc4bb4 100644
--- a/sys/arch/amiga/amiga/locore.s
+++ b/sys/arch/amiga/amiga/locore.s
@@ -1,4 +1,4 @@
-/*	$OpenBSD: locore.s,v 1.28 2000/05/28 03:55:21 art Exp $	*/
+/*	$OpenBSD: locore.s,v 1.29 2000/06/05 11:02:55 art Exp $	*/
 /*	$NetBSD: locore.s,v 1.89 1997/07/17 16:22:54 is Exp $	*/
 
 /*
@@ -1223,16 +1223,10 @@ ENTRY(switch_exit)
 	movl	#nullpcb,_curpcb	| save state into garbage pcb
 	lea	tmpstk,sp		| goto a tmp stack
 
-	/* Free old process's user area. */
-	movl	#USPACE,sp@-		| size of u-area
-	movl	a0@(P_ADDR),sp@-	| address u-area of process
-	movl	_kernel_map,sp@-	| map it was allocated in
-#if defined(UVM)
-	jbsr	_uvm_km_free		| deallocate it
-#else
-	jbsr	_kmem_free		| deallocate it
-#endif
-	lea	sp@(12),sp		| pop args
+        /* Schedule the vmspace and stack to be freed. */
+	movl    a0,sp@-                 | exit2(p)
+	jbsr    _C_LABEL(exit2)
+	lea     sp@(4),sp               | pop args
 
 	jra	_cpu_switch
 
diff --git a/sys/arch/amiga/amiga/vm_machdep.c b/sys/arch/amiga/amiga/vm_machdep.c
index c9d782fe27a..70490213a40 100644
--- a/sys/arch/amiga/amiga/vm_machdep.c
+++ b/sys/arch/amiga/amiga/vm_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vm_machdep.c,v 1.13 2000/05/28 03:55:21 art Exp $	*/
+/*	$OpenBSD: vm_machdep.c,v 1.14 2000/06/05 11:02:56 art Exp $	*/
 /*	$NetBSD: vm_machdep.c,v 1.30 1997/05/19 10:14:50 veego Exp $	*/
 
 /*
@@ -151,12 +151,7 @@ void
 cpu_exit(p)
 	struct proc *p;
 {
-#if defined(UVM)
-	uvmspace_free(p->p_vmspace);
-#else
-	vmspace_free(p->p_vmspace);
-#endif
-	
+
 	(void)splhigh();
 #if defined(UVM)
 	uvmexp.swtch++;
diff --git a/sys/arch/hp300/hp300/locore.s b/sys/arch/hp300/hp300/locore.s
index 77ecd302818..5e0e831126c 100644
--- a/sys/arch/hp300/hp300/locore.s
+++ b/sys/arch/hp300/hp300/locore.s
@@ -1,4 +1,4 @@
-/*	$OpenBSD: locore.s,v 1.21 1998/09/06 20:09:59 millert Exp $	*/
+/*	$OpenBSD: locore.s,v 1.22 2000/06/05 11:02:57 art Exp $	*/
 /*	$NetBSD: locore.s,v 1.79 1997/09/12 08:41:55 mycroft Exp $	*/
 
 /*
@@ -1221,12 +1221,10 @@ ENTRY(switch_exit)
 	movl	#_ASM_LABEL(nullpcb),_C_LABEL(curpcb)
 	lea	_ASM_LABEL(tmpstk),sp	| goto a tmp stack
 
-	/* Free old process's resources. */
-	movl	#USPACE,sp@-		| size of u-area
-	movl	a0@(P_ADDR),sp@-	| address of process's u-area
-	movl	_C_LABEL(kernel_map),sp@- | map it was allocated in
-	jbsr	_C_LABEL(kmem_free)	| deallocate it
-	lea	sp@(12),sp		| pop args
+        /* Schedule the vmspace and stack to be freed. */
+	movl    a0,sp@-                 | exit2(p)
+	jbsr    _C_LABEL(exit2)
+	lea     sp@(4),sp               | pop args
 
 	jra	_C_LABEL(cpu_switch)
 
diff --git a/sys/arch/hp300/hp300/vm_machdep.c b/sys/arch/hp300/hp300/vm_machdep.c
index 337b16b1743..32c00e44189 100644
--- a/sys/arch/hp300/hp300/vm_machdep.c
+++ b/sys/arch/hp300/hp300/vm_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vm_machdep.c,v 1.14 1999/09/03 18:00:44 art Exp $	*/
+/*	$OpenBSD: vm_machdep.c,v 1.15 2000/06/05 11:02:57 art Exp $	*/
 /*	$NetBSD: vm_machdep.c,v 1.37 1997/05/26 00:27:43 thorpej Exp $	*/
 
 /*
@@ -134,8 +134,6 @@ cpu_exit(p)
 	struct proc *p;
 {
 
-	vmspace_free(p->p_vmspace);
-
 	(void) splimp();
 	cnt.v_swtch++;
 	switch_exit(p);
diff --git a/sys/arch/i386/i386/locore.s b/sys/arch/i386/i386/locore.s
index 5600f8c33c3..05c0f3dc1c0 100644
--- a/sys/arch/i386/i386/locore.s
+++ b/sys/arch/i386/i386/locore.s
@@ -1,4 +1,4 @@
-/*	$OpenBSD: locore.s,v 1.50 2000/05/01 00:43:41 mickey Exp $	*/
+/*	$OpenBSD: locore.s,v 1.51 2000/06/05 11:02:54 art Exp $	*/
 /*	$NetBSD: locore.s,v 1.145 1996/05/03 19:41:19 christos Exp $	*/
 
 /*-
@@ -1943,24 +1943,12 @@ ENTRY(switch_exit)
 	/* Interrupts are okay again. */
 	sti
 
-	/* Thoroughly nuke the old process's resources. */
-	pushl	P_ADDR(%edi)
-	call	_tss_free
-	pushl	P_VMSPACE(%edi)
-#if defined(UVM)
-	call	_C_LABEL(uvmspace_free)
-#else
-	call	_vmspace_free
-#endif
-	pushl	$USPACE
-	pushl	P_ADDR(%edi)
-	pushl	_kernel_map
-#if defined(UVM)
-	call	_C_LABEL(uvm_km_free)
-#else
-	call	_kmem_free
-#endif
-	addl	$20,%esp
+	/*
+	 * Schedule the dead process's vmspace and stack to be freed.
+	 */
+	pushl   %edi			/* exit2(p) */
+	call    _C_LABEL(exit2)
+	addl    $4,%esp
 
 	/* Jump into cpu_switch() with the right state. */
 	movl	%ebx,%esi
diff --git a/sys/arch/i386/i386/vm_machdep.c b/sys/arch/i386/i386/vm_machdep.c
index 78c3e5fa531..5ba85422128 100644
--- a/sys/arch/i386/i386/vm_machdep.c
+++ b/sys/arch/i386/i386/vm_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vm_machdep.c,v 1.17 1999/08/17 10:32:16 niklas Exp $	*/
+/*	$OpenBSD: vm_machdep.c,v 1.18 2000/06/05 11:02:54 art Exp $	*/
 /*	$NetBSD: vm_machdep.c,v 1.61 1996/05/03 19:42:35 christos Exp $	*/
 
 /*-
@@ -206,29 +206,12 @@ void
 cpu_exit(p)
 	register struct proc *p;
 {
-#ifdef USER_LDT
-	struct pcb *pcb;
-#endif
-	struct vmspace *vm;
-
 #if NNPX > 0
 	/* If we were using the FPU, forget about it. */
 	if (npxproc == p)
 		npxproc = 0;
 #endif
 
-#ifdef USER_LDT
-	pcb = &p->p_addr->u_pcb;
-	if (pcb->pcb_flags & PCB_USER_LDT)
-		i386_user_cleanup(pcb);
-#endif
-
-	vm = p->p_vmspace;
-#if !defined(UVM)
-	if (vm->vm_refcnt == 1)
-		vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS, VM_MAXUSER_ADDRESS);
-#endif
-
 #if defined(UVM)
 	uvmexp.swtch++;
 #else
@@ -237,6 +220,20 @@ cpu_exit(p)
 	switch_exit(p);
 }
 
+void
+cpu_wait(p)
+	struct proc *p;
+{
+	struct pcb *pcb;
+
+	pcb = &p->p_addr->u_pcb;
+#ifdef USER_LDT
+	if (pcb->pcb_flags & PCB_USER_LDT)
+		i386_user_cleanup(pcb);
+#endif
+	tss_free(pcb);
+}
+
 /*
  * Dump the machine specific segment at the start of a core dump.
  */     
diff --git a/sys/arch/kbus/include/pmap.h b/sys/arch/kbus/include/pmap.h
index 228516d859a..7f338b611d8 100644
--- a/sys/arch/kbus/include/pmap.h
+++ b/sys/arch/kbus/include/pmap.h
@@ -294,7 +294,8 @@ void pmap_bootstrap __P((vm_offset_t firstaddr));
 void pmap_disp_va __P((pmap_t pmap, vm_offset_t va));
 vm_offset_t pmap_map __P((vm_offset_t, vm_offset_t, vm_offset_t, int));
 struct user;
-void switchexit __P((vm_map_t, struct user *, int));
+struct proc;
+void switchexit __P((struct proc *));
 
 #endif	/* _KERNEL */
 #endif /* !_LOCORE */
diff --git a/sys/arch/kbus/kbus/locore.s b/sys/arch/kbus/kbus/locore.s
index 7c63f5c7938..97945eab30c 100644
--- a/sys/arch/kbus/kbus/locore.s
+++ b/sys/arch/kbus/kbus/locore.s
@@ -3087,8 +3087,6 @@ ENTRY(write_user_windows)
  */
 ENTRY(switchexit)
 	mov	%o0, %g2		! save the
-	mov	%o1, %g3		! ... three parameters
-	mov	%o2, %g4		! ... to kmem_free
 
 	/*
 	 * Change pcb to idle u. area, i.e., set %sp to top of stack
@@ -3119,10 +3117,8 @@ ENTRY(switchexit)
 	SET_SP_REDZONE(%l6, %l5)
 #endif
 	wr	%g0, PSR_S|PSR_ET, %psr	! and then enable traps
-	mov	%g2, %o0		! now ready to call kmem_free
-	mov	%g3, %o1
-	call	_kmem_free
-	 mov	%g4, %o2
+	call	_exit2
+	 mov	%g2, %o0
 
 	/*
 	 * Now fall through to `the last switch'.  %g6 was set to
diff --git a/sys/arch/kbus/kbus/vm_machdep.c b/sys/arch/kbus/kbus/vm_machdep.c
index 7c054c2029f..c80e06aa8d2 100644
--- a/sys/arch/kbus/kbus/vm_machdep.c
+++ b/sys/arch/kbus/kbus/vm_machdep.c
@@ -437,8 +437,8 @@ cpu_exit(p)
 		}
 		free((void *)fs, M_SUBPROC);
 	}
-	vmspace_free(p->p_vmspace);
-	switchexit(kernel_map, p->p_addr, USPACE);
+
+	switchexit(p);
 	/* NOTREACHED */
 }
 
diff --git a/sys/arch/mac68k/mac68k/locore.s b/sys/arch/mac68k/mac68k/locore.s
index efe1f0d149a..7e062a830b4 100644
--- a/sys/arch/mac68k/mac68k/locore.s
+++ b/sys/arch/mac68k/mac68k/locore.s
@@ -1,4 +1,4 @@
-/*	$OpenBSD: locore.s,v 1.22 1999/01/20 13:31:16 niklas Exp $	*/
+/*	$OpenBSD: locore.s,v 1.23 2000/06/05 11:02:59 art Exp $	*/
 /*	$NetBSD: locore.s,v 1.74 1997/02/02 08:17:46 thorpej Exp $	*/
 
 /*
@@ -1232,12 +1232,10 @@ ENTRY(switch_exit)
 	movl	#nullpcb,_curpcb	| save state into garbage pcb
 	lea	tmpstk,sp		| goto a tmp stack
 
-	/* Free old process's user area. */
-	movl	#USPACE,sp@-		| size of u-area
-	movl	a0@(P_ADDR),sp@-	| address of process's u-area
-	movl	_kernel_map,sp@-	| map it was allocated in
-	jbsr	_kmem_free		| deallocate it
-	lea	sp@(12),sp		| pop args
+        /* Schedule the vmspace and stack to be freed. */
+	movl    a0,sp@-                 | exit2(p)
+	jbsr    _C_LABEL(exit2)
+	lea     sp@(4),sp               | pop args
 
 	jra	_cpu_switch
 
diff --git a/sys/arch/mac68k/mac68k/vm_machdep.c b/sys/arch/mac68k/mac68k/vm_machdep.c
index 82e722ca7c5..e89a7fe0a9a 100644
--- a/sys/arch/mac68k/mac68k/vm_machdep.c
+++ b/sys/arch/mac68k/mac68k/vm_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vm_machdep.c,v 1.15 1999/10/10 18:29:22 art Exp $	*/
+/*	$OpenBSD: vm_machdep.c,v 1.16 2000/06/05 11:03:00 art Exp $	*/
 /*	$NetBSD: vm_machdep.c,v 1.21 1996/09/16 18:00:31 scottr Exp $	*/
 
 /*
@@ -153,7 +153,6 @@ volatile void
 cpu_exit(p)
 	struct proc *p;
 {
-	vmspace_free(p->p_vmspace);
 
 	(void) splhigh();
 	cnt.v_swtch++;
diff --git a/sys/arch/mips/mips/vm_machdep.c b/sys/arch/mips/mips/vm_machdep.c
index 72c64feb844..281e0974a0d 100644
--- a/sys/arch/mips/mips/vm_machdep.c
+++ b/sys/arch/mips/mips/vm_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vm_machdep.c,v 1.7 1999/09/03 18:01:18 art Exp $	*/
+/*	$OpenBSD: vm_machdep.c,v 1.8 2000/06/05 11:03:00 art Exp $	*/
 /*
  * Copyright (c) 1988 University of Utah.
  * Copyright (c) 1992, 1993
@@ -182,10 +182,8 @@ cpu_exit(p)
 	if (machFPCurProcPtr == p)
 		machFPCurProcPtr = (struct proc *)0;
 
-	vmspace_free(p->p_vmspace);
-
 	(void) splhigh();
-	kmem_free(kernel_map, (vm_offset_t)p->p_addr, ctob(UPAGES));
+	exit2(p);		/* XXX - probably very wrong */
 	switch_exit();
 	/* NOTREACHED */
 }
diff --git a/sys/arch/mvme68k/mvme68k/locore.s b/sys/arch/mvme68k/mvme68k/locore.s
index 9ec195e0c03..1cce4c1d1ea 100644
--- a/sys/arch/mvme68k/mvme68k/locore.s
+++ b/sys/arch/mvme68k/mvme68k/locore.s
@@ -1,4 +1,4 @@
-/*	$OpenBSD: locore.s,v 1.20 2000/01/06 03:21:43 smurph Exp $ */
+/*	$OpenBSD: locore.s,v 1.21 2000/06/05 11:03:01 art Exp $ */
 
 /*
  * Copyright (c) 1995 Theo de Raadt
@@ -1316,12 +1316,10 @@ ENTRY(switch_exit)
 	movl	#nullpcb,_curpcb	| save state into garbage pcb
 	lea	tmpstk,sp		| goto a tmp stack
 
-	/* Free old process's resources. */
-	movl	#USPACE,sp@-		| size of u-area
-	movl	a0@(P_ADDR),sp@-	| address of process's u-area
-	movl	_kernel_map,sp@-	| map it was allocated in
-	jbsr	_kmem_free		| deallocate it
-	lea	sp@(12),sp		| pop args
+        /* Schedule the vmspace and stack to be freed. */
+	movl    a0,sp@-                 | exit2(p)
+	jbsr    _C_LABEL(exit2)
+	lea     sp@(4),sp               | pop args
 
 	jra	_cpu_switch
 
diff --git a/sys/arch/mvme68k/mvme68k/vm_machdep.c b/sys/arch/mvme68k/mvme68k/vm_machdep.c
index 1722b359ce4..1182ded6de2 100644
--- a/sys/arch/mvme68k/mvme68k/vm_machdep.c
+++ b/sys/arch/mvme68k/mvme68k/vm_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vm_machdep.c,v 1.14 1999/09/27 20:30:32 smurph Exp $ */
+/*	$OpenBSD: vm_machdep.c,v 1.15 2000/06/05 11:03:02 art Exp $ */
 
 /*
  * Copyright (c) 1988 University of Utah.
@@ -130,8 +130,6 @@ cpu_exit(p)
 	struct proc *p;
 {
 
-	vmspace_free(p->p_vmspace);
-
 	(void) splimp();
 	cnt.v_swtch++;
 	switch_exit(p);
diff --git a/sys/arch/mvme88k/mvme88k/vm_machdep.c b/sys/arch/mvme88k/mvme88k/vm_machdep.c
index c3b3d79cef1..35cc2e080ef 100644
--- a/sys/arch/mvme88k/mvme88k/vm_machdep.c
+++ b/sys/arch/mvme88k/mvme88k/vm_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vm_machdep.c,v 1.11 1999/09/27 19:13:24 smurph Exp $	*/
+/*	$OpenBSD: vm_machdep.c,v 1.12 2000/06/05 11:03:02 art Exp $	*/
 /*
  * Copyright (c) 1998 Steve Murphree, Jr.
  * Copyright (c) 1996 Nivas Madhur
@@ -42,7 +42,7 @@
  *	from: Utah $Hdr: vm_machdep.c 1.21 91/04/06$
  *	from: @(#)vm_machdep.c	7.10 (Berkeley) 5/7/91
  *	vm_machdep.c,v 1.3 1993/07/07 07:09:32 cgd Exp
- *	$Id: vm_machdep.c,v 1.11 1999/09/27 19:13:24 smurph Exp $
+ *	$Id: vm_machdep.c,v 1.12 2000/06/05 11:03:02 art Exp $
  */
 
 #include <sys/param.h>
@@ -175,10 +175,9 @@ void
 cpu_exit(struct proc *p)
 {
 	extern volatile void switch_exit();
-	vmspace_free(p->p_vmspace);
 
 	(void) splimp();
-	kmem_free(kernel_map, (vm_offset_t)p->p_addr, ctob(UPAGES));
+	exit2(p);		/* XXX - can't be right! */
 	switch_exit(p);
 	/* NOTREACHED */
 }
diff --git a/sys/arch/pmax/pmax/vm_machdep.c b/sys/arch/pmax/pmax/vm_machdep.c
index f6d106324b0..3f376e84eba 100644
--- a/sys/arch/pmax/pmax/vm_machdep.c
+++ b/sys/arch/pmax/pmax/vm_machdep.c
@@ -186,10 +186,8 @@ void cpu_exit(p)
 	if (machFPCurProcPtr == p)
 		machFPCurProcPtr = (struct proc *)0;
 
-	vmspace_free(p->p_vmspace);
-
 	(void) splhigh();
-	kmem_free(kernel_map, (vm_offset_t)p->p_addr, ctob(UPAGES));
+	exit2(p);		/* XXX - probably very wrong. */
 	switch_exit();
 	/* NOTREACHED */
 }
diff --git a/sys/arch/powerpc/powerpc/locore.S b/sys/arch/powerpc/powerpc/locore.S
index 9283eeea4e9..2ee811ca8c9 100644
--- a/sys/arch/powerpc/powerpc/locore.S
+++ b/sys/arch/powerpc/powerpc/locore.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: locore.S,v 1.10 2000/03/31 04:11:02 rahnds Exp $	*/
+/*	$OpenBSD: locore.S,v 1.11 2000/06/05 11:03:03 art Exp $	*/
 /*	$NetBSD: locore.S,v 1.2 1996/10/16 19:33:09 ws Exp $	*/
 
 /*
@@ -194,12 +194,12 @@ _ENTRY(_C_LABEL(switchexit))
 	lis	7,_C_LABEL(curpcb)@ha
 	stw	6,_C_LABEL(curpcb)@l(7)
 	addi	1,6,USPACE-16		/* 16 bytes are reserved at stack top */
-/* Now free the old user structure (args are already in r3, r4, r5) */
-#ifdef UVM
-	bl	_C_LABEL(uvm_km_free)
-#else
-	bl	_C_LABEL(kmem_free)
-#endif
+	/*
+	 * Schedule the vmspace and stack to be freed (the proc arg is
+	 * already in r3).
+	 */
+	bl      _C_LABEL(exit2)
+	
 /* Fall through to cpu_switch to actually select another proc */
 
 /*
diff --git a/sys/arch/powerpc/powerpc/vm_machdep.c b/sys/arch/powerpc/powerpc/vm_machdep.c
index 88133ac3ef0..df840c21577 100644
--- a/sys/arch/powerpc/powerpc/vm_machdep.c
+++ b/sys/arch/powerpc/powerpc/vm_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vm_machdep.c,v 1.11 2000/01/16 22:52:22 rahnds Exp $	*/
+/*	$OpenBSD: vm_machdep.c,v 1.12 2000/06/05 11:03:04 art Exp $	*/
 /*	$NetBSD: vm_machdep.c,v 1.1 1996/09/30 16:34:57 ws Exp $	*/
 
 /*
@@ -180,13 +180,8 @@ cpu_exit(p)
 	if (p == fpuproc)	/* release the fpu */
 		fpuproc = 0;
 	
-#ifdef UVM
-	uvmspace_free(p->p_vmspace);
-#else
-	vmspace_free(p->p_vmspace);
-#endif
 	(void)splhigh();
-	switchexit(kernel_map, p->p_addr, USPACE);
+	switchexit(p);
 }
 
 /*
diff --git a/sys/arch/sparc/include/cpu.h b/sys/arch/sparc/include/cpu.h
index c510fb680d1..b0268a2c0ce 100644
--- a/sys/arch/sparc/include/cpu.h
+++ b/sys/arch/sparc/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.9 2000/05/18 13:31:12 jason Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.10 2000/06/05 11:02:52 art Exp $	*/
 /*	$NetBSD: cpu.h,v 1.24 1997/03/15 22:25:15 pk Exp $ */
 
 /*
@@ -75,7 +75,7 @@
  */
 #define	cpu_swapin(p)	/* nothing */
 #define	cpu_swapout(p)	/* nothing */
-#define	cpu_wait(p)	/* nothing */
+#define cpu_wait(p)	/* nothing */
 
 /*
  * Arguments to hardclock, softclock and gatherstats encapsulate the
diff --git a/sys/arch/sparc/include/pmap.h b/sys/arch/sparc/include/pmap.h
index 12cc90be105..ef9f26ee2cb 100644
--- a/sys/arch/sparc/include/pmap.h
+++ b/sys/arch/sparc/include/pmap.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pmap.h,v 1.15 1999/12/09 21:35:28 art Exp $	*/
+/*	$OpenBSD: pmap.h,v 1.16 2000/06/05 11:02:52 art Exp $	*/
 /*	$NetBSD: pmap.h,v 1.30 1997/08/04 20:00:47 pk Exp $ */
 
 /*
@@ -310,7 +310,7 @@ void		kvm_setcache __P((caddr_t, int, int));
 #define		kvm_recache(addr, npages) kvm_setcache(addr, npages, 1)
 void		pmap_cache_enable __P((void));
 struct user;
-void		switchexit __P((vm_map_t, struct user *, int));
+void		switchexit __P((struct proc *));
 int		mmu_pagein __P((struct pmap *pm, vaddr_t, int));
 void		pmap_writetext __P((unsigned char *, int));
 
diff --git a/sys/arch/sparc/sparc/locore.s b/sys/arch/sparc/sparc/locore.s
index f9f38a40298..49ca3f92005 100644
--- a/sys/arch/sparc/sparc/locore.s
+++ b/sys/arch/sparc/sparc/locore.s
@@ -1,4 +1,4 @@
-/*	$OpenBSD: locore.s,v 1.37 2000/02/27 05:25:01 deraadt Exp $	*/
+/*	$OpenBSD: locore.s,v 1.38 2000/06/05 11:02:53 art Exp $	*/
 /*	$NetBSD: locore.s,v 1.73 1997/09/13 20:36:48 pk Exp $	*/
 
 /*
@@ -4317,9 +4317,7 @@ ENTRY(write_user_windows)
  * and note that the `last loaded process' is nonexistent.
  */
 ENTRY(switchexit)
-	mov	%o0, %g2		! save the
-	mov	%o1, %g3		! ... three parameters
-	mov	%o2, %g4		! ... to kmem_free
+	mov	%o0, %g2		! save proc for exit2() call
 
 	/*
 	 * Change pcb to idle u. area, i.e., set %sp to top of stack
@@ -4341,14 +4339,8 @@ ENTRY(switchexit)
 	SET_SP_REDZONE(%l6, %l5)
 #endif
 	wr	%g0, PSR_S|PSR_ET, %psr	! and then enable traps
-	mov	%g2, %o0		! now ready to call kmem_free
-	mov	%g3, %o1
-#if defined(UVM)
-	call	_uvm_km_free
-#else
-	call	_kmem_free
-#endif
-	 mov	%g4, %o2
+	call    _exit2			! exit2(p)
+	 mov    %g2, %o0
 
 	/*
 	 * Now fall through to `the last switch'.  %g6 was set to
diff --git a/sys/arch/sparc/sparc/vm_machdep.c b/sys/arch/sparc/sparc/vm_machdep.c
index 5e3f1ddf892..4e311ed46ea 100644
--- a/sys/arch/sparc/sparc/vm_machdep.c
+++ b/sys/arch/sparc/sparc/vm_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vm_machdep.c,v 1.19 2000/05/01 18:28:58 art Exp $	*/
+/*	$OpenBSD: vm_machdep.c,v 1.20 2000/06/05 11:02:53 art Exp $	*/
 /*	$NetBSD: vm_machdep.c,v 1.30 1997/03/10 23:55:40 pk Exp $ */
 
 /*
@@ -521,10 +521,11 @@ cpu_set_kpc(p, pc, arg)
 
 /*
  * cpu_exit is called as the last action during exit.
- * We release the address space and machine-dependent resources,
- * including the memory for the user structure and kernel stack.
- * Since the latter is also the interrupt stack, we release it
- * from assembly code after switching to a temporary pcb+stack.
+ *
+ * We clean up a little and then call switchexit() with the old proc
+ * as an argument.  switchexit() switches to the idle context, schedules
+ * the old vmspace and stack to be freed, then selects a new process to
+ * run.
  */
 void
 cpu_exit(p)
@@ -539,12 +540,8 @@ cpu_exit(p)
 		}
 		free((void *)fs, M_SUBPROC);
 	}
-#if defined(UVM)
-	uvmspace_free(p->p_vmspace);
-#else
-	vmspace_free(p->p_vmspace);
-#endif
-	switchexit(kernel_map, p->p_addr, USPACE);
+
+	switchexit(p);
 	/* NOTREACHED */
 }
 
diff --git a/sys/arch/sun3/sun3/locore.s b/sys/arch/sun3/sun3/locore.s
index cc72f3f04fe..13ae9b105e4 100644
--- a/sys/arch/sun3/sun3/locore.s
+++ b/sys/arch/sun3/sun3/locore.s
@@ -1,4 +1,4 @@
-/*	$OpenBSD: locore.s,v 1.18 1997/04/05 20:22:01 kstailey Exp $	*/
+/*	$OpenBSD: locore.s,v 1.19 2000/06/05 11:03:04 art Exp $	*/
 /*	$NetBSD: locore.s,v 1.40 1996/11/06 20:19:54 cgd Exp $	*/
 
 /*
@@ -935,12 +935,10 @@ ENTRY(switch_exit)
 	lea	tmpstk,sp		| goto a tmp stack
 	movl	a0,sp@-			| pass proc ptr down
 
-	/* Free old process's u-area. */
-	movl	#USPACE,sp@-		| size of u-area
-	movl	a0@(P_ADDR),sp@-	| address of process's u-area
-	movl	_kernel_map,sp@-	| map it was allocated in
-	jbsr	_kmem_free		| deallocate it
-	lea	sp@(12),sp		| pop args
+        /* Schedule the vmspace and stack to be freed. */
+	movl    a0,sp@-                 | exit2(p)
+	jbsr    _C_LABEL(exit2)
+	lea     sp@(4),sp               | pop args
 
 	jra	_cpu_switch
 
diff --git a/sys/arch/sun3/sun3/vm_machdep.c b/sys/arch/sun3/sun3/vm_machdep.c
index cff257308c3..280dcea9a76 100644
--- a/sys/arch/sun3/sun3/vm_machdep.c
+++ b/sys/arch/sun3/sun3/vm_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vm_machdep.c,v 1.11 2000/03/02 23:02:15 todd Exp $	*/
+/*	$OpenBSD: vm_machdep.c,v 1.12 2000/06/05 11:03:04 art Exp $	*/
 /*	$NetBSD: vm_machdep.c,v 1.35 1996/04/26 18:38:06 gwr Exp $	*/
 
 /*
@@ -198,8 +198,6 @@ cpu_exit(p)
 	struct proc *p;
 {
 
-	vmspace_free(p->p_vmspace);
-
 	(void) splimp();
 	cnt.v_swtch++;
 	switch_exit(p);
diff --git a/sys/arch/vax/vax/subr.s b/sys/arch/vax/vax/subr.s
index 53cbee8332f..ec82a52c642 100644
--- a/sys/arch/vax/vax/subr.s
+++ b/sys/arch/vax/vax/subr.s
@@ -1,4 +1,4 @@
-/*	$OpenBSD: subr.s,v 1.7 2000/04/27 01:10:13 bjc Exp $     */
+/*	$OpenBSD: subr.s,v 1.8 2000/06/05 11:03:05 art Exp $     */
 /*	$NetBSD: subr.s,v 1.32 1999/03/25 00:41:48 mrg Exp $	   */
 
 /*
@@ -301,8 +301,8 @@ ENTRY(cpu_exit,0)
 	mtpr	$0x18,$PR_IPL	# Block almost everything
 	addl3	$512,_scratch,sp # Change stack, and schedule it to be freed
 
-	pushl	P_VMSPACE(r6)		
-	calls	$1,_uvmspace_free	
+	pushl	r6		
+	calls	$1,_exit2
 
 	clrl	r0		# No process to switch from
 	bicl3	$0xc0000000,_scratch,r1
diff --git a/sys/kern/init_main.c b/sys/kern/init_main.c
index 13ba4c4f93d..105ad19f43f 100644
--- a/sys/kern/init_main.c
+++ b/sys/kern/init_main.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: init_main.c,v 1.52 2000/03/23 16:54:44 art Exp $	*/
+/*	$OpenBSD: init_main.c,v 1.53 2000/06/05 11:02:50 art Exp $	*/
 /*	$NetBSD: init_main.c,v 1.84.4.1 1996/06/02 09:08:06 mrg Exp $	*/
 
 /*
@@ -140,6 +140,7 @@ void	check_console __P((struct proc *));
 void	start_init __P((void *));
 void	start_pagedaemon __P((void *));
 void	start_update __P((void *));
+void	start_reaper __P((void *));
 
 #ifdef cpu_set_init_frame
 void *initframep;				/* XXX should go away */
@@ -433,7 +434,11 @@ main(framep)
 	if (kthread_create(start_pagedaemon, NULL, NULL, "pagedaemon"))
 		panic("fork pagedaemon");
 
-	/* Create process 3, the update daemon kernel thread. */
+	/* Create process 3, the reaper daemon kernel thread. */
+	if (kthread_create(start_reaper, NULL, NULL, "reaper"))
+		panic("fork reaper");
+
+	/* Create process 4, the update daemon kernel thread. */
 	if (kthread_create(start_update, NULL, NULL, "update")) {
 #ifdef DIAGNOSTIC
 		panic("fork update");
@@ -657,3 +662,11 @@ start_update(arg)
 	sched_sync(curproc);
 	/* NOTREACHED */
 }
+
+void
+start_reaper(arg)
+	void *arg;
+{
+	reaper();
+	/* NOTREACHED */
+}
diff --git a/sys/kern/kern_exit.c b/sys/kern/kern_exit.c
index a854b511733..bed30ca982f 100644
--- a/sys/kern/kern_exit.c
+++ b/sys/kern/kern_exit.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_exit.c,v 1.24 2000/05/05 08:38:23 art Exp $	*/
+/*	$OpenBSD: kern_exit.c,v 1.25 2000/06/05 11:02:50 art Exp $	*/
 /*	$NetBSD: kern_exit.c,v 1.39 1996/04/22 01:38:25 christos Exp $	*/
 
 /*
@@ -213,15 +213,24 @@ exit1(p, rv)
 		ktrsettracevnode(p, NULL);
 #endif
 	/*
-	 * Remove proc from allproc queue and pidhash chain.
-	 * Place onto zombproc.  Unlink from parent's child list.
+	 * NOTE: WE ARE NO LONGER ALLOWED TO SLEEP!
 	 */
+	p->p_stat = SDEAD;
+
+        /*
+         * Remove proc from pidhash chain so looking it up won't
+         * work.  Move it from allproc to zombproc, but do not yet
+         * wake up the reaper.  We will put the proc on the
+         * deadproc list later (using the p_hash member), and
+         * wake up the reaper when we do.
+         */
+	LIST_REMOVE(p, p_hash);
 	LIST_REMOVE(p, p_list);
 	LIST_INSERT_HEAD(&zombproc, p, p_list);
-	p->p_stat = SZOMB;
-
-	LIST_REMOVE(p, p_hash);
 
+	/*
+	 * Give orphaned children to init(8).
+	 */
 	q = p->p_children.lh_first;
 	if (q)		/* only need this if any child is S_ZOMB */
 		wakeup((caddr_t)initproc);
@@ -268,18 +277,13 @@ exit1(p, rv)
 		if (pp->p_children.lh_first == NULL)
 			wakeup((caddr_t)pp);
 	}
-	psignal(p->p_pptr, SIGCHLD);
-	wakeup((caddr_t)p->p_pptr);
 
 	/*
 	 * Notify procfs debugger
 	 */
 	if (p->p_flag & P_FSTRACE)
 		wakeup((caddr_t)p);
-#if defined(tahoe)
-	/* move this to cpu_exit */
-	p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL;
-#endif
+
 	/*
 	 * Clear curproc after we've done all operations
 	 * that could block, and before tearing down the rest
@@ -295,17 +299,94 @@ exit1(p, rv)
 	p->p_limit = NULL;
 
 	/*
-	 * Finally, call machine-dependent code to release the remaining
-	 * resources including address space, the kernel stack and pcb.
-	 * The address space is released by "vmspace_free(p->p_vmspace)";
-	 * This is machine-dependent, as we may have to change stacks
-	 * or ensure that the current one isn't reallocated before we
-	 * finish.  cpu_exit will end with a call to cpu_swtch(), finishing
-	 * our execution (pun intended).
+	 * Finally, call machine-dependent code to switch to a new
+	 * context (possibly the idle context).  Once we are no longer
+	 * using the dead process's vmspace and stack, exit2() will be
+	 * called to schedule those resources to be released by the
+	 * reaper thread.
+	 *
+	 * Note that cpu_exit() will end with a call equivalent to
+	 * cpu_switch(), finishing our execution (pun intended).
 	 */
 	cpu_exit(p);
 }
 
+/*
+ * We are called from cpu_exit() once it is safe to schedule the
+ * dead process's resources to be freed.
+ *
+ * NOTE: One must be careful with locking in this routine.  It's
+ * called from a critical section in machine-dependent code, so
+ * we should refrain from changing any interrupt state.
+ *
+ * We lock the deadproc list (a spin lock), place the proc on that
+ * list (using the p_hash member), and wake up the reaper.
+ */
+void
+exit2(p)
+	struct proc *p;
+{
+
+	simple_lock(&deadproc_slock);
+	LIST_INSERT_HEAD(&deadproc, p, p_hash);
+	simple_unlock(&deadproc_slock);
+
+	wakeup(&deadproc);
+}
+
+/*
+ * Process reaper.  This is run by a kernel thread to free the resources
+ * of a dead process.  Once the resources are free, the process becomes
+ * a zombie, and the parent is allowed to read the undead's status.
+ */
+void
+reaper()
+{
+	struct proc *p;
+
+	for (;;) {
+		simple_lock(&deadproc_slock);
+		p = LIST_FIRST(&deadproc);
+		if (p == NULL) {
+			/* No work for us; go to sleep until someone exits. */
+			simple_unlock(&deadproc_slock);
+			(void) tsleep(&deadproc, PVM, "reaper", 0);
+			continue;
+		}
+
+		/* Remove us from the deadproc list. */
+		LIST_REMOVE(p, p_hash);
+		simple_unlock(&deadproc_slock);
+
+		/*
+		 * Give machine-dependent code a chance to free any
+		 * resources it couldn't free while still running on
+		 * that process's context.  This must be done before
+		 * uvm_exit(), in case these resources are in the PCB.
+		 */
+		cpu_wait(p);
+
+#ifdef UVM
+		/*
+		 * Free the VM resources we're still holding on to.
+		 * We must do this from a valid thread because doing
+		 * so may block.
+		 */
+		uvm_exit(p);
+#else
+		vmspace_free(p->p_vmspace);
+		kmem_free(kernel_map, (vaddr_t)p->p_addr, USPACE);
+#endif
+
+		/* Process is now a true zombie. */
+		p->p_stat = SZOMB;
+
+		/* Wake up the parent so it can get exit status. */
+		psignal(p->p_pptr, SIGCHLD);
+		wakeup((caddr_t)p->p_pptr);
+	}
+}
+
 int
 sys_wait4(q, v, retval)
 	register struct proc *q;
@@ -354,7 +435,7 @@ loop:
 			if (SCARG(uap, rusage) &&
 			    (error = copyout((caddr_t)p->p_ru,
 			    (caddr_t)SCARG(uap, rusage),
-			    sizeof (struct rusage))))
+			    sizeof(struct rusage))))
 				return (error);
 			/*
 			 * If we got the child via a ptrace 'attach',
@@ -400,12 +481,6 @@ loop:
 			if (p->p_textvp)
 				vrele(p->p_textvp);
 
-			/*
-			 * Give machine-dependent layer a chance
-			 * to free anything that cpu_exit couldn't
-			 * release while still running in process context.
-			 */
-			cpu_wait(p);
 			FREE(p, M_PROC);
 			nprocs--;
 			return (0);
diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c
index d431cc3315b..b8bfac34f4d 100644
--- a/sys/kern/kern_proc.c
+++ b/sys/kern/kern_proc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_proc.c,v 1.6 1999/04/28 09:28:14 art Exp $	*/
+/*	$OpenBSD: kern_proc.c,v 1.7 2000/06/05 11:02:50 art Exp $	*/
 /*	$NetBSD: kern_proc.c,v 1.14 1996/02/09 18:59:41 christos Exp $	*/
 
 /*
@@ -75,6 +75,16 @@ u_long pgrphash;
 struct proclist allproc;
 struct proclist zombproc;
 
+/*
+ * Locking of this proclist is special; it's accessed in a
+ * critical section of process exit, and thus locking it can't
+ * modify interrupt state.  We use a simple spin lock for this
+ * proclist.  Processes on this proclist are also on zombproc;
+ * we use the p_hash member to linkup to deadproc.
+ */
+struct simplelock deadproc_slock;
+struct proclist deadproc;		/* dead, but not yet undead */
+
 static void orphanpg __P((struct pgrp *));
 #ifdef DEBUG
 void pgrpdump __P((void));
@@ -89,6 +99,10 @@ procinit()
 
 	LIST_INIT(&allproc);
 	LIST_INIT(&zombproc);
+
+	LIST_INIT(&deadproc);
+	simple_lock_init(&deadproc_slock);
+
 	pidhashtbl = hashinit(maxproc / 4, M_PROC, M_WAITOK, &pidhash);
 	pgrphashtbl = hashinit(maxproc / 4, M_PROC, M_WAITOK, &pgrphash);
 	uihashtbl = hashinit(maxproc / 16, M_PROC, M_WAITOK, &uihash);
@@ -325,7 +339,7 @@ fixjobc(p, pgrp, entering)
 	for (p = p->p_children.lh_first; p != 0; p = p->p_sibling.le_next)
 		if ((hispgrp = p->p_pgrp) != pgrp &&
 		    hispgrp->pg_session == mysession &&
-		    p->p_stat != SZOMB) {
+		    P_ZOMBIE(p) == 0) {
 			if (entering)
 				hispgrp->pg_jobc++;
 			else if (--hispgrp->pg_jobc == 0)
diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index de148e69821..caadb6620fa 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_sig.c,v 1.37 2000/04/21 15:47:27 millert Exp $	*/
+/*	$OpenBSD: kern_sig.c,v 1.38 2000/06/05 11:02:50 art Exp $	*/
 /*	$NetBSD: kern_sig.c,v 1.54 1996/04/22 01:38:32 christos Exp $	*/
 
 /*
@@ -542,7 +542,7 @@ killpg1(cp, signum, pgid, all)
 			    !cansignal(cp, pc, p, signum))
 				continue;
 			nfound++;
-			if (signum)
+			if (signum && P_ZOMBIE(p) == 0)
 				psignal(p, signum);
 		}
 	}
diff --git a/sys/kern/kern_synch.c b/sys/kern/kern_synch.c
index 59b50786171..7ca4b4fc1ce 100644
--- a/sys/kern/kern_synch.c
+++ b/sys/kern/kern_synch.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_synch.c,v 1.24 2000/04/19 09:58:20 art Exp $	*/
+/*	$OpenBSD: kern_synch.c,v 1.25 2000/06/05 11:02:51 art Exp $	*/
 /*	$NetBSD: kern_synch.c,v 1.37 1996/04/22 01:38:37 christos Exp $	*/
 
 /*-
@@ -754,6 +754,7 @@ setrunnable(p)
 	case 0:
 	case SRUN:
 	case SZOMB:
+	case SDEAD:
 	default:
 		panic("setrunnable");
 	case SSTOP:
diff --git a/sys/kern/kern_sysctl.c b/sys/kern/kern_sysctl.c
index 5db51a627e7..eca6d0e08da 100644
--- a/sys/kern/kern_sysctl.c
+++ b/sys/kern/kern_sysctl.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_sysctl.c,v 1.34 2000/05/06 17:08:14 deraadt Exp $	*/
+/*	$OpenBSD: kern_sysctl.c,v 1.35 2000/06/05 11:02:51 art Exp $	*/
 /*	$NetBSD: kern_sysctl.c,v 1.17 1996/05/20 17:49:05 mrg Exp $	*/
 
 /*-
@@ -806,7 +806,7 @@ fill_eproc(p, ep)
 	ep->e_sess = p->p_pgrp->pg_session;
 	ep->e_pcred = *p->p_cred;
 	ep->e_ucred = *p->p_ucred;
-	if (p->p_stat == SIDL || p->p_stat == SZOMB) {
+	if (p->p_stat == SIDL || P_ZOMBIE(p)) {
 		ep->e_vm.vm_rssize = 0;
 		ep->e_vm.vm_tsize = 0;
 		ep->e_vm.vm_dsize = 0;
diff --git a/sys/kern/tty.c b/sys/kern/tty.c
index e43024e9108..fa632857111 100644
--- a/sys/kern/tty.c
+++ b/sys/kern/tty.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tty.c,v 1.39 2000/03/23 17:20:23 art Exp $	*/
+/*	$OpenBSD: tty.c,v 1.40 2000/06/05 11:02:51 art Exp $	*/
 /*	$NetBSD: tty.c,v 1.68.4.2 1996/06/06 16:04:52 thorpej Exp $	*/
 
 /*-
@@ -2034,7 +2034,7 @@ ttyinfo(tp)
 		tmp = (pick->p_pctcpu * 10000 + FSCALE / 2) >> FSHIFT;
 		ttyprintf(tp, "%d%% %ldk\n",
 		    tmp / 100,
-		    pick->p_stat == SIDL || pick->p_stat == SZOMB ? 0 :
+		    pick->p_stat == SIDL || P_ZOMBIE(pick) ? 0 :
 			vm_resident_count(pick->p_vmspace));
 	}
 	tp->t_rocount = 0;	/* so pending input will be retyped if BS */
@@ -2087,7 +2087,7 @@ proc_compare(p1, p2)
 	/*
  	 * weed out zombies
 	 */
-	switch (TESTAB(p1->p_stat == SZOMB, p2->p_stat == SZOMB)) {
+	switch (TESTAB(P_ZOMBIE(p1), P_ZOMBIE(p2))) {
 	case ONLYA:
 		return (1);
 	case ONLYB:
diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index 9ddd84f1a93..5ed87c3de54 100644
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: proc.h,v 1.30 2000/04/19 09:58:19 art Exp $	*/
+/*	$OpenBSD: proc.h,v 1.31 2000/06/05 11:02:48 art Exp $	*/
 /*	$NetBSD: proc.h,v 1.44 1996/04/22 01:23:21 christos Exp $	*/
 
 /*-
@@ -214,6 +214,9 @@ struct	proc {
 #define	SSLEEP	3		/* Sleeping on an address. */
 #define	SSTOP	4		/* Process debugging or suspension. */
 #define	SZOMB	5		/* Awaiting collection by parent. */
+#define SDEAD	6		/* Process is almost a zombie. */
+
+#define P_ZOMBIE(p)	((p)->p_stat == SZOMB || (p)->p_stat == SDEAD)
 
 /* These flags are kept in p_flag. */
 #define	P_ADVLOCK	0x000001	/* Proc may hold a POSIX adv. lock. */
@@ -325,6 +328,10 @@ extern int randompid;			/* fork() should create random pid's */
 LIST_HEAD(proclist, proc);
 extern struct proclist allproc;		/* List of all processes. */
 extern struct proclist zombproc;	/* List of zombie processes. */
+
+extern struct proclist deadproc;	/* List of dead processes. */
+extern struct simplelock deadproc_slock;
+
 struct proc *initproc;			/* Process slots for init, pager. */
 
 #define	NQS	32			/* 32 run queues. */
@@ -360,7 +367,9 @@ void	swapin __P((struct proc *));
 int	tsleep __P((void *chan, int pri, char *wmesg, int timo));
 void	unsleep __P((struct proc *));
 void	wakeup __P((void *chan));
+void	reaper __P((void));
 void	exit1 __P((struct proc *, int));
+void	exit2 __P((struct proc *));
 int	fork1 __P((struct proc *, int, void *, size_t, register_t *));
 void	kmeminit __P((void));
 void	rqinit __P((void));