Since p_flag is often manipulated in interrupts and without biglock

it's a good idea to use atomic.h operations on it. This mechanic
change updates all bit operations on p_flag to atomic_{set,clear}bits_int.

Only exception is that P_OWEUPC is set by MI code before calling
need_proftick and it's automatically cleared by ADDUPC. There's
no reason for MD handling of that flag since everyone handles it the
same way.

kettenis@ ok

57 files changed, 155 insertions, 178 deletions

diff --git a/sys/arch/alpha/alpha/trap.c b/sys/arch/alpha/alpha/trap.c
index 99172106797..36babce98c3 100644
--- a/sys/arch/alpha/alpha/trap.c
+++ b/sys/arch/alpha/alpha/trap.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: trap.c,v 1.52 2006/12/24 20:30:33 miod Exp $ */
+/* $OpenBSD: trap.c,v 1.53 2007/03/15 10:22:29 art Exp $ */
 /* $NetBSD: trap.c,v 1.52 2000/05/24 16:48:33 thorpej Exp $ */
 
 /*-
@@ -768,7 +768,6 @@ ast(framep)
 	uvmexp.softs++;
 
 	if (p->p_flag & P_OWEUPC) {
-		p->p_flag &= ~P_OWEUPC;
 		ADDUPROF(p);
 	}
 
diff --git a/sys/arch/alpha/include/cpu.h b/sys/arch/alpha/include/cpu.h
index ef4b6b09503..8f1dcfeeaca 100644
--- a/sys/arch/alpha/include/cpu.h
+++ b/sys/arch/alpha/include/cpu.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: cpu.h,v 1.26 2006/12/24 20:30:35 miod Exp $ */
+/* $OpenBSD: cpu.h,v 1.27 2007/03/15 10:22:29 art Exp $ */
 /* $NetBSD: cpu.h,v 1.45 2000/08/21 02:03:12 thorpej Exp $ */
 
 /*-
@@ -296,13 +296,11 @@ do {									\
 #ifdef notyet
 #define	need_proftick(p)						\
 do {									\
-	(p)->p_flag |= P_OWEUPC;					\
 	aston((p)->p_cpu);						\
 } while (/*CONSTCOND*/0)
 #else
 #define	need_proftick(p)						\
 do {									\
-	(p)->p_flag |= P_OWEUPC;					\
 	aston(curcpu());						\
 } while (/*CONSTCOND*/0)
 #endif
diff --git a/sys/arch/amd64/amd64/trap.c b/sys/arch/amd64/amd64/trap.c
index 24451f7d6da..358592235d3 100644
--- a/sys/arch/amd64/amd64/trap.c
+++ b/sys/arch/amd64/amd64/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.10 2007/01/15 23:19:05 jsg Exp $	*/
+/*	$OpenBSD: trap.c,v 1.11 2007/03/15 10:22:29 art Exp $	*/
 /*	$NetBSD: trap.c,v 1.2 2003/05/04 23:51:56 fvdl Exp $	*/
 
 /*-
@@ -334,7 +334,6 @@ copyfault:
 	case T_ASTFLT|T_USER:		/* Allow process switch */
 		uvmexp.softs++;
 		if (p->p_flag & P_OWEUPC) {
-			p->p_flag &= ~P_OWEUPC;
 			KERNEL_PROC_LOCK(p);
 			ADDUPROF(p);
 			KERNEL_PROC_UNLOCK(p);
diff --git a/sys/arch/amd64/include/cpu.h b/sys/arch/amd64/include/cpu.h
index 38d4b66ed09..55ef0ec6bd5 100644
--- a/sys/arch/amd64/include/cpu.h
+++ b/sys/arch/amd64/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.25 2007/02/17 17:35:43 tom Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.26 2007/03/15 10:22:29 art Exp $	*/
 /*	$NetBSD: cpu.h,v 1.1 2003/04/26 18:39:39 fvdl Exp $	*/
 
 /*-
@@ -227,7 +227,7 @@ extern u_int32_t cpus_attached;
  * buffer pages are invalid.  On the i386, request an ast to send us
  * through trap(), marking the proc as needing a profiling tick.
  */
-#define	need_proftick(p)	((p)->p_flag |= P_OWEUPC, aston(p))
+#define	need_proftick(p)	aston(p)
 
 void signotify(struct proc *);
 
diff --git a/sys/arch/arm/arm/ast.c b/sys/arch/arm/arm/ast.c
index 8ba315e3687..8bc5c0394bc 100644
--- a/sys/arch/arm/arm/ast.c
+++ b/sys/arch/arm/arm/ast.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ast.c,v 1.6 2006/12/24 20:30:35 miod Exp $	*/
+/*	$OpenBSD: ast.c,v 1.7 2007/03/15 10:22:29 art Exp $	*/
 /*	$NetBSD: ast.c,v 1.6 2003/10/31 16:44:34 cl Exp $	*/
 
 /*
@@ -114,7 +114,6 @@ ast(struct trapframe *tf)
 #endif	
 
 	if (p->p_flag & P_OWEUPC) {
-		p->p_flag &= ~P_OWEUPC;
 		ADDUPROF(p);
 	}
 
diff --git a/sys/arch/arm/include/cpu.h b/sys/arch/arm/include/cpu.h
index fa4396b5558..faa66b3cbdb 100644
--- a/sys/arch/arm/include/cpu.h
+++ b/sys/arch/arm/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.14 2007/02/11 21:59:32 miod Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.15 2007/03/15 10:22:29 art Exp $	*/
 /*	$NetBSD: cpu.h,v 1.34 2003/06/23 11:01:08 martin Exp $	*/
 
 /*
@@ -260,7 +260,7 @@ extern int want_resched;	/* resched() was called */
  * buffer pages are invalid.  On the i386, request an ast to send us
  * through trap(), marking the proc as needing a profiling tick.
  */
-#define	need_proftick(p)	((p)->p_flag |= P_OWEUPC, setsoftast())
+#define	need_proftick(p)	setsoftast()
 
 #ifndef acorn26
 /*
diff --git a/sys/arch/hp300/hp300/trap.c b/sys/arch/hp300/hp300/trap.c
index 0a8d3b895ae..a408e050cbf 100644
--- a/sys/arch/hp300/hp300/trap.c
+++ b/sys/arch/hp300/hp300/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.49 2007/01/28 16:38:45 miod Exp $	*/
+/*	$OpenBSD: trap.c,v 1.50 2007/03/15 10:22:29 art Exp $	*/
 /*	$NetBSD: trap.c,v 1.57 1998/02/16 20:58:31 thorpej Exp $	*/
 
 /*
@@ -556,7 +556,6 @@ dopanic:
 		}
 		spl0();
 		if (p->p_flag & P_OWEUPC) {
-			p->p_flag &= ~P_OWEUPC;
 			ADDUPROF(p);
 		}
 		if (type == (T_ASTFLT | T_USER) && want_resched) {
diff --git a/sys/arch/hp300/include/cpu.h b/sys/arch/hp300/include/cpu.h
index df051c819cc..56d22c6a43e 100644
--- a/sys/arch/hp300/include/cpu.h
+++ b/sys/arch/hp300/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.32 2006/11/29 12:26:13 miod Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.33 2007/03/15 10:22:29 art Exp $	*/
 /*	$NetBSD: cpu.h,v 1.28 1998/02/13 07:41:51 scottr Exp $	*/
 
 /*
@@ -96,7 +96,7 @@ extern int want_resched;	/* resched() was called */
  * buffer pages are invalid.  On the hp300, request an ast to send us
  * through trap, marking the proc as needing a profiling tick.
  */
-#define	need_proftick(p)	{ (p)->p_flag |= P_OWEUPC; aston(); }
+#define	need_proftick(p)	aston()
 
 /*
  * Notify the current process (p) that it has a signal pending,
diff --git a/sys/arch/hppa/hppa/trap.c b/sys/arch/hppa/hppa/trap.c
index 07e06fc9659..cabcae3e572 100644
--- a/sys/arch/hppa/hppa/trap.c
+++ b/sys/arch/hppa/hppa/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.97 2007/03/05 17:13:59 mickey Exp $	*/
+/*	$OpenBSD: trap.c,v 1.98 2007/03/15 10:22:29 art Exp $	*/
 
 /*
  * Copyright (c) 1998-2004 Michael Shalayeff
@@ -139,7 +139,6 @@ userret(struct proc *p)
 		astpending = 0;
 		uvmexp.softs++;
 		if (p->p_flag & P_OWEUPC) {
-			p->p_flag &= ~P_OWEUPC;
 			ADDUPROF(p);
 		}
 		if (want_resched)
diff --git a/sys/arch/hppa/include/cpu.h b/sys/arch/hppa/include/cpu.h
index 04a70b07691..8ccf039327c 100644
--- a/sys/arch/hppa/include/cpu.h
+++ b/sys/arch/hppa/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.47 2007/01/17 19:30:12 mickey Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.48 2007/03/15 10:22:29 art Exp $	*/
 
 /*
  * Copyright (c) 2000-2004 Michael Shalayeff
@@ -128,7 +128,7 @@ extern int cpu_hvers;
 
 #define	signotify(p)		(setsoftast())
 #define	need_resched(ci)	(want_resched = 1, setsoftast())
-#define	need_proftick(p)	((p)->p_flag |= P_OWEUPC, setsoftast())
+#define	need_proftick(p)	setsoftast()
 #define	PROC_PC(p)		((p)->p_md.md_regs->tf_iioq_head)
 
 #ifndef _LOCORE
diff --git a/sys/arch/hppa64/hppa64/trap.c b/sys/arch/hppa64/hppa64/trap.c
index 73ff5be1703..63b57f6886b 100644
--- a/sys/arch/hppa64/hppa64/trap.c
+++ b/sys/arch/hppa64/hppa64/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.6 2005/10/26 18:35:45 martin Exp $	*/
+/*	$OpenBSD: trap.c,v 1.7 2007/03/15 10:22:29 art Exp $	*/
 
 /*
  * Copyright (c) 2005 Michael Shalayeff
@@ -128,7 +128,6 @@ userret(struct proc *p, register_t pc, u_quad_t oticks)
 	if (astpending) {
 		astpending = 0;
 		if (p->p_flag & P_OWEUPC) {
-			p->p_flag &= ~P_OWEUPC;
 			ADDUPROF(p);
 		}
 	}
diff --git a/sys/arch/hppa64/include/cpu.h b/sys/arch/hppa64/include/cpu.h
index 43cc46203aa..b88a04dea2b 100644
--- a/sys/arch/hppa64/include/cpu.h
+++ b/sys/arch/hppa64/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.9 2006/03/12 03:14:37 brad Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.10 2007/03/15 10:22:29 art Exp $	*/
 
 /*
  * Copyright (c) 2005 Michael Shalayeff
@@ -196,7 +196,7 @@ extern int cpu_hvers;
 
 #define	signotify(p)		(setsoftast())
 #define	need_resched(ci)	(want_resched = 1, setsoftast())
-#define	need_proftick(p)	((p)->p_flag |= P_OWEUPC, setsoftast())
+#define	need_proftick(p)	setsoftast()
 
 #ifndef _LOCORE
 #ifdef _KERNEL
diff --git a/sys/arch/i386/i386/trap.c b/sys/arch/i386/i386/trap.c
index 37c2fd28b26..0bea0095d56 100644
--- a/sys/arch/i386/i386/trap.c
+++ b/sys/arch/i386/i386/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.81 2007/01/09 08:43:25 art Exp $	*/
+/*	$OpenBSD: trap.c,v 1.82 2007/03/15 10:22:29 art Exp $	*/
 /*	$NetBSD: trap.c,v 1.95 1996/05/05 06:50:02 mycroft Exp $	*/
 
 /*-
@@ -383,7 +383,6 @@ trap(struct trapframe frame)
 	case T_ASTFLT|T_USER:		/* Allow process switch */
 		uvmexp.softs++;
 		if (p->p_flag & P_OWEUPC) {
-			p->p_flag &= ~P_OWEUPC;
 			KERNEL_PROC_LOCK(p);
 			ADDUPROF(p);
 			KERNEL_PROC_UNLOCK(p);
diff --git a/sys/arch/i386/include/cpu.h b/sys/arch/i386/include/cpu.h
index 153e6f2c608..a066cbea0bb 100644
--- a/sys/arch/i386/include/cpu.h
+++ b/sys/arch/i386/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.87 2007/02/20 21:15:01 tom Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.88 2007/03/15 10:22:29 art Exp $	*/
 /*	$NetBSD: cpu.h,v 1.35 1996/05/05 19:29:26 christos Exp $	*/
 
 /*-
@@ -224,7 +224,7 @@ extern void need_resched(struct cpu_info *);
  * buffer pages are invalid.  On the i386, request an ast to send us
  * through trap(), marking the proc as needing a profiling tick.
  */
-#define	need_proftick(p)	((p)->p_flag |= P_OWEUPC, setsoftast())
+#define	need_proftick(p)	setsoftast()
 
 /*
  * Notify the current process (p) that it has a signal pending,
diff --git a/sys/arch/m88k/include/cpu.h b/sys/arch/m88k/include/cpu.h
index 08b797c5372..697cfcfc9af 100644
--- a/sys/arch/m88k/include/cpu.h
+++ b/sys/arch/m88k/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.18 2007/01/12 21:41:53 aoyama Exp $ */
+/*	$OpenBSD: cpu.h,v 1.19 2007/03/15 10:22:29 art Exp $ */
 /*
  * Copyright (c) 1996 Nivas Madhur
  * Copyright (c) 1992, 1993
@@ -229,7 +229,7 @@ do {									\
  * buffer pages are invalid.  On the m88k, request an ast to send us
  * through trap(), marking the proc as needing a profiling tick.
  */
-#define	need_proftick(p)	((p)->p_flag |= P_OWEUPC, aston(p))
+#define	need_proftick(p)	aston(p)
 
 /*
  * Notify the current process (p) that it has a signal pending,
diff --git a/sys/arch/m88k/m88k/trap.c b/sys/arch/m88k/m88k/trap.c
index df5f44870af..4de452d5ebf 100644
--- a/sys/arch/m88k/m88k/trap.c
+++ b/sys/arch/m88k/m88k/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.38 2007/02/11 12:49:37 miod Exp $	*/
+/*	$OpenBSD: trap.c,v 1.39 2007/03/15 10:22:29 art Exp $	*/
 /*
  * Copyright (c) 2004, Miodrag Vallat.
  * Copyright (c) 1998 Steve Murphree, Jr.
@@ -538,7 +538,6 @@ user_fault:
 		uvmexp.softs++;
 		p->p_md.md_astpending = 0;
 		if (p->p_flag & P_OWEUPC) {
-			p->p_flag &= ~P_OWEUPC;
 			KERNEL_PROC_LOCK(p);
 			ADDUPROF(p);
 			KERNEL_PROC_UNLOCK(p);
@@ -1055,7 +1054,6 @@ m88110_user_fault:
 		uvmexp.softs++;
 		p->p_md.md_astpending = 0;
 		if (p->p_flag & P_OWEUPC) {
-			p->p_flag &= ~P_OWEUPC;
 			KERNEL_PROC_LOCK(p);
 			ADDUPROF(p);
 			KERNEL_PROC_UNLOCK(p);
diff --git a/sys/arch/mac68k/include/cpu.h b/sys/arch/mac68k/include/cpu.h
index b97efff30d5..dec5f7811e2 100644
--- a/sys/arch/mac68k/include/cpu.h
+++ b/sys/arch/mac68k/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.42 2006/11/29 12:26:13 miod Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.43 2007/03/15 10:22:29 art Exp $	*/
 /*	$NetBSD: cpu.h,v 1.45 1997/02/10 22:13:40 scottr Exp $	*/
 
 /*
@@ -109,7 +109,7 @@ extern int want_resched;	/* resched() was called */
  * interrupt.  Request an ast to send us through trap(),
  * marking the proc as needing a profiling tick.
  */
-#define	need_proftick(p)	( (p)->p_flag |= P_OWEUPC, aston() )
+#define	need_proftick(p)	aston()
 
 /*
  * Notify the current process (p) that it has a signal pending,
diff --git a/sys/arch/mac68k/mac68k/trap.c b/sys/arch/mac68k/mac68k/trap.c
index 7d14554196b..bc706b11f63 100644
--- a/sys/arch/mac68k/mac68k/trap.c
+++ b/sys/arch/mac68k/mac68k/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.51 2007/01/28 16:38:48 miod Exp $	*/
+/*	$OpenBSD: trap.c,v 1.52 2007/03/15 10:22:29 art Exp $	*/
 /*	$NetBSD: trap.c,v 1.68 1998/12/22 08:47:07 scottr Exp $	*/
 
 /*
@@ -511,7 +511,6 @@ copyfault:
 		}
 		spl0();
 		if (p->p_flag & P_OWEUPC) {
-			p->p_flag &= ~P_OWEUPC;
 			ADDUPROF(p);
 		}
 		if (type == (T_ASTFLT | T_USER) && want_resched) {
diff --git a/sys/arch/mips64/include/cpu.h b/sys/arch/mips64/include/cpu.h
index def5c9e20c4..d24ef984e32 100644
--- a/sys/arch/mips64/include/cpu.h
+++ b/sys/arch/mips64/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.14 2006/12/24 20:30:35 miod Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.15 2007/03/15 10:22:29 art Exp $	*/
 
 /*-
  * Copyright (c) 1992, 1993
@@ -349,7 +349,7 @@ extern int int_nest_cntr;
  * buffer pages are invalid.  On the PICA, request an ast to send us
  * through trap, marking the proc as needing a profiling tick.
  */
-#define	need_proftick(p)	{ (p)->p_flag |= P_OWEUPC; aston(); }
+#define	need_proftick(p)	aston()
 
 /*
  * Notify the current process (p) that it has a signal pending,
diff --git a/sys/arch/mips64/mips64/interrupt.c b/sys/arch/mips64/mips64/interrupt.c
index 59d1aed120d..0cf196762fa 100644
--- a/sys/arch/mips64/mips64/interrupt.c
+++ b/sys/arch/mips64/mips64/interrupt.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: interrupt.c,v 1.22 2006/12/24 20:30:35 miod Exp $ */
+/*	$OpenBSD: interrupt.c,v 1.23 2007/03/15 10:22:29 art Exp $ */
 
 /*
  * Copyright (c) 2001-2004 Opsycon AB  (www.opsycon.se / www.opsycon.com)
@@ -267,7 +267,6 @@ softintr()
 
 	astpending = 0;
 	if (p->p_flag & P_OWEUPC) {
-		p->p_flag &= ~P_OWEUPC;
 		ADDUPROF(p);
 	}
 	if (want_resched)
diff --git a/sys/arch/mvme68k/include/cpu.h b/sys/arch/mvme68k/include/cpu.h
index 11e0a01ed04..a7caae93d53 100644
--- a/sys/arch/mvme68k/include/cpu.h
+++ b/sys/arch/mvme68k/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.25 2006/11/29 12:26:13 miod Exp $ */
+/*	$OpenBSD: cpu.h,v 1.26 2007/03/15 10:22:29 art Exp $ */
 
 /*
  * Copyright (c) 1995 Theo de Raadt
@@ -121,7 +121,7 @@ extern int want_resched;
  * buffer pages are invalid.  On the m68k, request an ast to send us
  * through trap, marking the proc as needing a profiling tick.
  */
-#define	need_proftick(p)	{ (p)->p_flag |= P_OWEUPC; aston(); }
+#define	need_proftick(p)	aston()
 
 /*
  * Notify the current process (p) that it has a signal pending,
diff --git a/sys/arch/mvme68k/mvme68k/trap.c b/sys/arch/mvme68k/mvme68k/trap.c
index cb72380c5a2..41fbfcc4b7c 100644
--- a/sys/arch/mvme68k/mvme68k/trap.c
+++ b/sys/arch/mvme68k/mvme68k/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.64 2007/01/28 16:38:48 miod Exp $ */
+/*	$OpenBSD: trap.c,v 1.65 2007/03/15 10:22:29 art Exp $ */
 
 /*
  * Copyright (c) 1995 Theo de Raadt
@@ -491,7 +491,6 @@ copyfault:
 		}
 		spl0();
 		if (p->p_flag & P_OWEUPC) {
-			p->p_flag &= ~P_OWEUPC;
 			ADDUPROF(p);
 		}
 		if (type == (T_ASTFLT | T_USER) && want_resched) {
diff --git a/sys/arch/powerpc/include/cpu.h b/sys/arch/powerpc/include/cpu.h
index d6c4026e087..d89ed88c158 100644
--- a/sys/arch/powerpc/include/cpu.h
+++ b/sys/arch/powerpc/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.28 2006/11/29 12:26:13 miod Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.29 2007/03/15 10:22:29 art Exp $	*/
 /*	$NetBSD: cpu.h,v 1.1 1996/09/30 16:34:21 ws Exp $	*/
 
 /*
@@ -51,7 +51,7 @@ extern volatile int want_resched;
 extern volatile int astpending;
 
 #define	need_resched(ci)	(want_resched = 1, astpending = 1)
-#define	need_proftick(p)	((p)->p_flag |= P_OWEUPC, astpending = 1)
+#define	need_proftick(p)	do { astpending = 1; } while (0)
 #define	signotify(p)		(astpending = 1)
 
 extern char *bootpath;
diff --git a/sys/arch/powerpc/powerpc/trap.c b/sys/arch/powerpc/powerpc/trap.c
index a5548f62226..c5c67b3f456 100644
--- a/sys/arch/powerpc/powerpc/trap.c
+++ b/sys/arch/powerpc/powerpc/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.73 2006/12/24 20:29:19 miod Exp $	*/
+/*	$OpenBSD: trap.c,v 1.74 2007/03/15 10:22:29 art Exp $	*/
 /*	$NetBSD: trap.c,v 1.3 1996/10/13 03:31:37 christos Exp $	*/
 
 /*
@@ -644,7 +644,6 @@ for (i = 0; i < errnum; i++) {
 		uvmexp.softs++;
 		astpending = 0;		/* we are about to do it */
 		if (p->p_flag & P_OWEUPC) {
-			p->p_flag &= ~P_OWEUPC;
 			ADDUPROF(p);
 		}
 		if (want_resched)
diff --git a/sys/arch/sh/include/cpu.h b/sys/arch/sh/include/cpu.h
index a4906007317..61f0faf3f89 100644
--- a/sys/arch/sh/include/cpu.h
+++ b/sys/arch/sh/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.6 2007/03/03 21:37:27 miod Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.7 2007/03/15 10:22:29 art Exp $	*/
 /*	$NetBSD: cpu.h,v 1.41 2006/01/21 04:24:12 uwe Exp $	*/
 
 /*-
@@ -88,11 +88,7 @@ do {									\
  * buffer pages are invalid.  On the MIPS, request an ast to send us
  * through trap, marking the proc as needing a profiling tick.
  */
-#define	need_proftick(p)						\
-do {									\
-	(p)->p_flag |= P_OWEUPC;					\
-	aston(p);							\
-} while (/*CONSTCOND*/0)
+#define	need_proftick(p)	aston(p)
 
 /*
  * Notify the current process (p) that it has a signal pending,
diff --git a/sys/arch/sh/sh/trap.c b/sys/arch/sh/sh/trap.c
index dd8a510e078..d5b503d17c3 100644
--- a/sys/arch/sh/sh/trap.c
+++ b/sys/arch/sh/sh/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.11 2007/03/13 19:29:33 miod Exp $	*/
+/*	$OpenBSD: trap.c,v 1.12 2007/03/15 10:22:29 art Exp $	*/
 /*	$NetBSD: exception.c,v 1.32 2006/09/04 23:57:52 uwe Exp $	*/
 /*	$NetBSD: syscall.c,v 1.6 2006/03/07 07:21:50 thorpej Exp $	*/
 
@@ -488,7 +488,6 @@ ast(struct proc *p, struct trapframe *tf)
 		p->p_md.md_astpending = 0;
 
 		if (p->p_flag & P_OWEUPC) {
-			p->p_flag &= ~P_OWEUPC;
 			ADDUPROF(p);
 		}
 
diff --git a/sys/arch/solbourne/solbourne/trap.c b/sys/arch/solbourne/solbourne/trap.c
index e2ac576e8ad..345ff5525d5 100644
--- a/sys/arch/solbourne/solbourne/trap.c
+++ b/sys/arch/solbourne/solbourne/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.8 2006/12/24 20:30:35 miod Exp $	*/
+/*	$OpenBSD: trap.c,v 1.9 2007/03/15 10:22:29 art Exp $	*/
 /*	OpenBSD: trap.c,v 1.42 2004/12/06 20:12:25 miod Exp 	*/
 
 /*
@@ -348,7 +348,6 @@ badtrap:
 	case T_AST:
 		want_ast = 0;
 		if (p->p_flag & P_OWEUPC) {
-			p->p_flag &= ~P_OWEUPC;
 			ADDUPROF(p);
 		}
 		if (want_resched)
diff --git a/sys/arch/sparc/include/cpu.h b/sys/arch/sparc/include/cpu.h
index 6cab3d88eab..c866f1d4803 100644
--- a/sys/arch/sparc/include/cpu.h
+++ b/sys/arch/sparc/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.27 2006/12/24 20:30:35 miod Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.28 2007/03/15 10:22:29 art Exp $	*/
 /*	$NetBSD: cpu.h,v 1.24 1997/03/15 22:25:15 pk Exp $ */
 
 /*
@@ -141,7 +141,7 @@ extern int	want_ast;
  * buffer pages are invalid.  On the sparc, request an ast to send us
  * through trap(), marking the proc as needing a profiling tick.
  */
-#define	need_proftick(p)	((p)->p_flag |= P_OWEUPC, want_ast = 1)
+#define	need_proftick(p)	do { want_ast = 1; } while (0)
 
 /*
  * Notify the current process (p) that it has a signal pending,
diff --git a/sys/arch/sparc/sparc/trap.c b/sys/arch/sparc/sparc/trap.c
index 7ea961d5ecb..01aa8002472 100644
--- a/sys/arch/sparc/sparc/trap.c
+++ b/sys/arch/sparc/sparc/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.50 2006/12/24 20:30:35 miod Exp $	*/
+/*	$OpenBSD: trap.c,v 1.51 2007/03/15 10:22:30 art Exp $	*/
 /*	$NetBSD: trap.c,v 1.58 1997/09/12 08:55:01 pk Exp $ */
 
 /*
@@ -341,7 +341,6 @@ badtrap:
 	case T_AST:
 		want_ast = 0;
 		if (p->p_flag & P_OWEUPC) {
-			p->p_flag &= ~P_OWEUPC;
 			ADDUPROF(p);
 		}
 		if (want_resched)
diff --git a/sys/arch/sparc64/include/cpu.h b/sys/arch/sparc64/include/cpu.h
index 66d66500796..d5a6400e7ac 100644
--- a/sys/arch/sparc64/include/cpu.h
+++ b/sys/arch/sparc64/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.37 2006/12/24 20:30:35 miod Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.38 2007/03/15 10:22:30 art Exp $	*/
 /*	$NetBSD: cpu.h,v 1.28 2001/06/14 22:56:58 thorpej Exp $ */
 
 /*
@@ -174,7 +174,7 @@ extern	int want_resched;	/* resched() was called */
  * buffer pages are invalid.  On the sparc, request an ast to send us
  * through trap(), marking the proc as needing a profiling tick.
  */
-#define	need_proftick(p)	((p)->p_flag |= P_OWEUPC, want_ast = 1)
+#define	need_proftick(p)	do { want_ast = 1; } while (0)
 
 /*
  * Notify the current process (p) that it has a signal pending,
diff --git a/sys/arch/sparc64/sparc64/trap.c b/sys/arch/sparc64/sparc64/trap.c
index 00e590f3c32..a7761e289c9 100644
--- a/sys/arch/sparc64/sparc64/trap.c
+++ b/sys/arch/sparc64/sparc64/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.46 2007/02/27 22:46:32 deraadt Exp $	*/
+/*	$OpenBSD: trap.c,v 1.47 2007/03/15 10:22:30 art Exp $	*/
 /*	$NetBSD: trap.c,v 1.73 2001/08/09 01:03:01 eeh Exp $ */
 
 /*
@@ -498,7 +498,6 @@ badtrap:
 	case T_AST:
 		want_ast = 0;
 		if (p->p_flag & P_OWEUPC) {
-			p->p_flag &= ~P_OWEUPC;
 			ADDUPROF(p);
 		}
 		if (want_resched)
diff --git a/sys/arch/vax/include/cpu.h b/sys/arch/vax/include/cpu.h
index 0191390c8cf..bc291df29e6 100644
--- a/sys/arch/vax/include/cpu.h
+++ b/sys/arch/vax/include/cpu.h
@@ -1,4 +1,4 @@
-/*      $OpenBSD: cpu.h,v 1.22 2006/12/24 20:30:35 miod Exp $      */
+/*      $OpenBSD: cpu.h,v 1.23 2007/03/15 10:22:30 art Exp $      */
 /*      $NetBSD: cpu.h,v 1.41 1999/10/21 20:01:36 ragge Exp $      */
 
 /*
@@ -112,7 +112,7 @@ extern	int     want_resched;   /* resched() was called */
  * buffer pages are invalid.  On the vax, request an ast to send us
  * through trap, marking the proc as needing a profiling tick.
  */
-#define need_proftick(p) {(p)->p_flag |= P_OWEUPC; mtpr(AST_OK,PR_ASTLVL); }
+#define need_proftick(p) mtpr(AST_OK,PR_ASTLVL)
 
 /*
  * This defines the I/O device register space size in pages.
diff --git a/sys/arch/vax/vax/trap.c b/sys/arch/vax/vax/trap.c
index 37f901282f6..c32a9f7a8d3 100644
--- a/sys/arch/vax/vax/trap.c
+++ b/sys/arch/vax/vax/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.36 2006/12/24 20:30:35 miod Exp $     */
+/*	$OpenBSD: trap.c,v 1.37 2007/03/15 10:22:30 art Exp $     */
 /*	$NetBSD: trap.c,v 1.47 1999/08/21 19:26:20 matt Exp $     */
 /*
  * Copyright (c) 1994 Ludd, University of Lule}, Sweden.
@@ -291,7 +291,6 @@ if(faultdebug)printf("trap accflt type %lx, code %lx, pc %lx, psl %lx\n",
 		mtpr(AST_NO,PR_ASTLVL);
 		trapsig = 0;
 		if (p->p_flag & P_OWEUPC) {
-			p->p_flag &= ~P_OWEUPC;
 			ADDUPROF(p);
 		}
 		if (want_resched)
diff --git a/sys/compat/hpux/hpux_file.c b/sys/compat/hpux/hpux_file.c
index 63daf9ed6fc..cad38f912b3 100644
--- a/sys/compat/hpux/hpux_file.c
+++ b/sys/compat/hpux/hpux_file.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: hpux_file.c,v 1.17 2006/09/25 07:12:57 otto Exp $	*/
+/*	$OpenBSD: hpux_file.c,v 1.18 2007/03/15 10:22:30 art Exp $	*/
 /*	$NetBSD: hpux_file.c,v 1.5 1997/04/27 21:40:48 thorpej Exp $	*/
 
 /*
@@ -282,7 +282,7 @@ hpux_sys_fcntl(p, v, retval)
 				goto out;
 			}
 
-			p->p_flag |= P_ADVLOCK;
+			atomic_setbits_int(&p->p_flag, P_ADVLOCK);
 			error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &fl, flg);
 			goto out;
 
@@ -291,7 +291,7 @@ hpux_sys_fcntl(p, v, retval)
 				error = EBADF;
 				goto out;
 			}
-			p->p_flag |= P_ADVLOCK;
+			atomic_setbits_int(&p->p_flag, P_ADVLOCK);
 			error = VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &fl, flg);
 			goto out;
 
diff --git a/sys/compat/osf1/osf1_prot.c b/sys/compat/osf1/osf1_prot.c
index f37abf0add1..6f4a860661d 100644
--- a/sys/compat/osf1/osf1_prot.c
+++ b/sys/compat/osf1/osf1_prot.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: osf1_prot.c,v 1.2 2003/08/16 21:34:30 tedu Exp $ */
+/* $OpenBSD: osf1_prot.c,v 1.3 2007/03/15 10:22:30 art Exp $ */
 /* $NetBSD: osf1_prot.c,v 1.2 1999/05/05 01:51:35 cgd Exp $ */
 
 /*
@@ -96,7 +96,7 @@ osf1_sys_setgid(p, v, retval)
 		pc->p_rgid = gid;
 		pc->p_svgid = gid;
 	}
-	p->p_flag |= P_SUGID;
+	atomic_setbits_int(&p->p_flag, P_SUGID);
 	return (0);
 }
 
@@ -137,6 +137,6 @@ osf1_sys_setuid(p, v, retval)
 		pc->p_ruid = uid;
 		pc->p_svuid = uid;
 	}
-	p->p_flag |= P_SUGID;
+	atomic_setbits_int(&p->p_flag, P_SUGID);
 	return (0);
 }
diff --git a/sys/compat/svr4/svr4_misc.c b/sys/compat/svr4/svr4_misc.c
index 287e0a4a8f3..1d100d71e6a 100644
--- a/sys/compat/svr4/svr4_misc.c
+++ b/sys/compat/svr4/svr4_misc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: svr4_misc.c,v 1.46 2006/05/23 20:34:22 miod Exp $	 */
+/*	$OpenBSD: svr4_misc.c,v 1.47 2007/03/15 10:22:30 art Exp $	 */
 /*	$NetBSD: svr4_misc.c,v 1.42 1996/12/06 03:22:34 christos Exp $	 */
 
 /*
@@ -1111,7 +1111,7 @@ loop:
 		    (SCARG(uap, options) & (SVR4_WSTOPPED|SVR4_WCONTINUED)))) {
 			DPRINTF(("jobcontrol %d\n", p->p_pid));
 			if (((SCARG(uap, options) & SVR4_WNOWAIT)) == 0)
-				p->p_flag |= P_WAITED;
+				atomic_setbits_int(&p->p_flag, P_WAITED);
 			*retval = 0;
 			return (svr4_setinfo(p, W_STOPCODE(p->p_xstat),
 			   SCARG(uap, info)));
diff --git a/sys/dev/systrace.c b/sys/dev/systrace.c
index 3620497433f..2ab5a06512c 100644
--- a/sys/dev/systrace.c
+++ b/sys/dev/systrace.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: systrace.c,v 1.43 2006/10/06 05:47:27 djm Exp $	*/
+/*	$OpenBSD: systrace.c,v 1.44 2007/03/15 10:22:30 art Exp $	*/
 /*
  * Copyright 2002 Niels Provos <provos@citi.umich.edu>
  * All rights reserved.
@@ -648,7 +648,7 @@ systrace_exit(struct proc *proc)
 		rw_exit_write(&fst->lock);
 	} else
 		systrace_unlock();
-	CLR(proc->p_flag, P_SYSTRACE);
+	atomic_clearbits_int(&proc->p_flag, P_SYSTRACE);
 }
 
 void
@@ -926,7 +926,7 @@ systrace_seteuid(struct proc *p,  uid_t euid)
 	 */
 	pc->pc_ucred = crcopy(pc->pc_ucred);
 	pc->pc_ucred->cr_uid = euid;
-	p->p_flag |= P_SUGID;
+	atomic_setbits_int(&p->p_flag, P_SUGID);
 
 	return (oeuid);
 }
@@ -945,7 +945,7 @@ systrace_setegid(struct proc *p,  gid_t egid)
 	 */
 	pc->pc_ucred = crcopy(pc->pc_ucred);
 	pc->pc_ucred->cr_gid = egid;
-	p->p_flag |= P_SUGID;
+	atomic_setbits_int(&p->p_flag, P_SUGID);
 
 	return (oegid);
 }
@@ -1579,7 +1579,7 @@ systrace_detach(struct str_process *strp)
 	DPRINTF(("%s: Trying to detach from %d\n", __func__, strp->pid));
 
 	if ((proc = systrace_find(strp)) != NULL) {
-		CLR(proc->p_flag, P_SYSTRACE);
+		atomic_clearbits_int(&proc->p_flag, P_SYSTRACE);
 		proc->p_systrace = NULL;
 	} else
 		error = ESRCH;
@@ -1641,7 +1641,7 @@ systrace_insert_process(struct fsystrace *fst, struct proc *proc)
 	fst->nprocesses++;
 
 	proc->p_systrace = strp;
-	SET(proc->p_flag, P_SYSTRACE);
+	atomic_setbits_int(&proc->p_flag, P_SYSTRACE);
 
 	return (0);
 }
diff --git a/sys/kern/init_main.c b/sys/kern/init_main.c
index 2d90604ff43..f54f517f4f8 100644
--- a/sys/kern/init_main.c
+++ b/sys/kern/init_main.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: init_main.c,v 1.134 2007/01/12 07:41:31 art Exp $	*/
+/*	$OpenBSD: init_main.c,v 1.135 2007/03/15 10:22:30 art Exp $	*/
 /*	$NetBSD: init_main.c,v 1.84.4.1 1996/06/02 09:08:06 mrg Exp $	*/
 
 /*
@@ -270,7 +270,7 @@ main(void *framep)
 	p->p_thrparent = p;
 	LIST_INIT(&p->p_thrchildren);
 
-	p->p_flag = P_SYSTEM | P_NOCLDWAIT;
+	atomic_setbits_int(&p->p_flag, P_SYSTEM | P_NOCLDWAIT);
 	p->p_stat = SONPROC;
 	p->p_nice = NZERO;
 	p->p_emul = &emul_native;
diff --git a/sys/kern/kern_clock.c b/sys/kern/kern_clock.c
index 024bc6cc2ae..ba55361a277 100644
--- a/sys/kern/kern_clock.c
+++ b/sys/kern/kern_clock.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_clock.c,v 1.60 2006/12/24 20:29:45 miod Exp $	*/
+/*	$OpenBSD: kern_clock.c,v 1.61 2007/03/15 10:22:30 art Exp $	*/
 /*	$NetBSD: kern_clock.c,v 1.34 1996/06/09 04:51:03 briggs Exp $	*/
 
 /*-
@@ -446,7 +446,7 @@ startprofclock(struct proc *p)
 	int s;
 
 	if ((p->p_flag & P_PROFIL) == 0) {
-		p->p_flag |= P_PROFIL;
+		atomic_setbits_int(&p->p_flag, P_PROFIL);
 		if (++profprocs == 1 && stathz != 0) {
 			s = splstatclock();
 			psdiv = pscnt = psratio;
@@ -465,7 +465,7 @@ stopprofclock(struct proc *p)
 	int s;
 
 	if (p->p_flag & P_PROFIL) {
-		p->p_flag &= ~P_PROFIL;
+		atomic_clearbits_int(&p->p_flag, P_PROFIL);
 		if (--profprocs == 0 && stathz != 0) {
 			s = splstatclock();
 			psdiv = pscnt = 1;
diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c
index 8d9c1189032..d2946c2edc4 100644
--- a/sys/kern/kern_descrip.c
+++ b/sys/kern/kern_descrip.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_descrip.c,v 1.75 2006/11/14 18:00:27 jmc Exp $	*/
+/*	$OpenBSD: kern_descrip.c,v 1.76 2007/03/15 10:22:30 art Exp $	*/
 /*	$NetBSD: kern_descrip.c,v 1.42 1996/03/30 22:24:38 christos Exp $	*/
 
 /*
@@ -430,7 +430,7 @@ restart:
 				error = EBADF;
 				goto out;
 			}
-			p->p_flag |= P_ADVLOCK;
+			atomic_setbits_int(&p->p_flag, P_ADVLOCK);
 			error = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &fl, flg));
 			goto out;
 
@@ -439,7 +439,7 @@ restart:
 				error = EBADF;
 				goto out;
 			}
-			p->p_flag |= P_ADVLOCK;
+			atomic_setbits_int(&p->p_flag, P_ADVLOCK);
 			error = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &fl, flg));
 			goto out;
 
diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c
index 60aad9c4f37..e7c598f460c 100644
--- a/sys/kern/kern_exec.c
+++ b/sys/kern/kern_exec.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_exec.c,v 1.101 2007/03/01 11:18:40 art Exp $	*/
+/*	$OpenBSD: kern_exec.c,v 1.102 2007/03/15 10:22:30 art Exp $	*/
 /*	$NetBSD: kern_exec.c,v 1.75 1996/02/09 18:59:28 christos Exp $	*/
 
 /*-
@@ -267,7 +267,7 @@ sys_execve(struct proc *p, void *v, register_t *retval)
 	 * Cheap solution to complicated problems.
 	 * Mark this process as "leave me alone, I'm execing".
 	 */
-	p->p_flag |= P_INEXEC;
+	atomic_setbits_int(&p->p_flag, P_INEXEC);
 
 #if NSYSTRACE > 0
 	if (ISSET(p->p_flag, P_SYSTRACE)) {
@@ -464,9 +464,9 @@ sys_execve(struct proc *p, void *v, register_t *retval)
 	VREF(pack.ep_vp);
 	p->p_textvp = pack.ep_vp;
 
-	p->p_flag |= P_EXEC;
+	atomic_setbits_int(&p->p_flag, P_EXEC);
 	if (p->p_flag & P_PPWAIT) {
-		p->p_flag &= ~P_PPWAIT;
+		atomic_clearbits_int(&p->p_flag, P_PPWAIT);
 		wakeup((caddr_t)p->p_pptr);
 	}
 
@@ -478,9 +478,9 @@ sys_execve(struct proc *p, void *v, register_t *retval)
 	    p->p_ucred->cr_uid != p->p_cred->p_svuid ||
 	    p->p_ucred->cr_gid != p->p_cred->p_rgid ||
 	    p->p_ucred->cr_gid != p->p_cred->p_svgid)
-		p->p_flag |= P_SUGIDEXEC;
+		atomic_setbits_int(&p->p_flag, P_SUGIDEXEC);
 	else
-		p->p_flag &= ~P_SUGIDEXEC;
+		atomic_clearbits_int(&p->p_flag, P_SUGIDEXEC);
 
 	/*
 	 * deal with set[ug]id.
@@ -489,8 +489,7 @@ sys_execve(struct proc *p, void *v, register_t *retval)
 	if ((attr.va_mode & (VSUID | VSGID)) && proc_cansugid(p)) {
 		int i;
 
-		p->p_flag |= P_SUGID;
-		p->p_flag |= P_SUGIDEXEC;
+		atomic_setbits_int(&p->p_flag, P_SUGID|P_SUGIDEXEC);
 
 #ifdef KTRACE
 		/*
@@ -571,7 +570,7 @@ sys_execve(struct proc *p, void *v, register_t *retval)
 			}
 		}
 	} else
-		p->p_flag &= ~P_SUGID;
+		atomic_clearbits_int(&p->p_flag, P_SUGID);
 	p->p_cred->p_svuid = p->p_ucred->cr_uid;
 	p->p_cred->p_svgid = p->p_ucred->cr_gid;
 
@@ -652,7 +651,7 @@ sys_execve(struct proc *p, void *v, register_t *retval)
 		ktremul(p, p->p_emul->e_name);
 #endif
 
-	p->p_flag &= ~P_INEXEC;
+	atomic_clearbits_int(&p->p_flag, P_INEXEC);
 
 #if NSYSTRACE > 0
 	if (ISSET(p->p_flag, P_SYSTRACE) &&
@@ -688,7 +687,7 @@ bad:
 #if NSYSTRACE > 0
  clrflag:
 #endif
-	p->p_flag &= ~P_INEXEC;
+	atomic_clearbits_int(&p->p_flag, P_INEXEC);
 
 	if (pathbuf != NULL)
 		pool_put(&namei_pool, pathbuf);
@@ -716,7 +715,7 @@ free_pack_abort:
 	exit1(p, W_EXITCODE(0, SIGABRT), EXIT_NORMAL);
 
 	/* NOTREACHED */
-	p->p_flag &= ~P_INEXEC;
+	atomic_clearbits_int(&p->p_flag, P_INEXEC);
 	if (pathbuf != NULL)
 		pool_put(&namei_pool, pathbuf);
 
diff --git a/sys/kern/kern_exit.c b/sys/kern/kern_exit.c
index 4c0a01cf19c..9823b41e223 100644
--- a/sys/kern/kern_exit.c
+++ b/sys/kern/kern_exit.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_exit.c,v 1.62 2006/06/23 13:46:05 mickey Exp $	*/
+/*	$OpenBSD: kern_exit.c,v 1.63 2007/03/15 10:22:30 art Exp $	*/
 /*	$NetBSD: kern_exit.c,v 1.39 1996/04/22 01:38:25 christos Exp $	*/
 
 /*
@@ -131,17 +131,17 @@ exit1(struct proc *p, int rv, int flags)
 		 * we are one of the threads.  we SIGKILL the parent,
 		 * it will wake us up again, then we proceed.
 		 */
-		p->p_thrparent->p_flag |= P_IGNEXITRV;
+		atomic_setbits_int(&p->p_thrparent->p_flag, P_IGNEXITRV);
 		p->p_thrparent->p_xstat = rv;
 		psignal(p->p_thrparent, SIGKILL);
 		tsleep(&p->p_thrparent->p_thrchildren, PUSER, "thrdying", 0);
 	} else if (p == p->p_thrparent) {
-		p->p_flag |= P_WEXIT;
+		atomic_setbits_int(&p->p_flag, P_WEXIT);
 		if (flags == EXIT_NORMAL) {
 			q = LIST_FIRST(&p->p_thrchildren);
 			for (; q != NULL; q = nq) {
 				nq = LIST_NEXT(q, p_thrsib);
-				q->p_flag |= P_IGNEXITRV;
+				atomic_setbits_int(&q->p_flag, P_IGNEXITRV);
 				q->p_xstat = rv;
 				psignal(q, SIGKILL);
 			}
@@ -159,10 +159,10 @@ exit1(struct proc *p, int rv, int flags)
 	 * If parent is waiting for us to exit or exec, P_PPWAIT is set; we
 	 * wake up the parent early to avoid deadlock.
 	 */
-	p->p_flag |= P_WEXIT;
-	p->p_flag &= ~P_TRACED;
+	atomic_setbits_int(&p->p_flag, P_WEXIT);
+	atomic_clearbits_int(&p->p_flag, P_TRACED);
 	if (p->p_flag & P_PPWAIT) {
-		p->p_flag &= ~P_PPWAIT;
+		atomic_clearbits_int(&p->p_flag, P_PPWAIT);
 		wakeup(p->p_pptr);
 	}
 	p->p_sigignore = ~0;
@@ -258,7 +258,7 @@ exit1(struct proc *p, int rv, int flags)
 		 * since their existence means someone is screwing up.
 		 */
 		if (q->p_flag & P_TRACED) {
-			q->p_flag &= ~P_TRACED;
+			atomic_clearbits_int(&q->p_flag, P_TRACED);
 			psignal(q, SIGKILL);
 		}
 	}
@@ -523,7 +523,7 @@ loop:
 		}
 		if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 &&
 		    (p->p_flag & P_TRACED || SCARG(uap, options) & WUNTRACED)) {
-			p->p_flag |= P_WAITED;
+			atomic_setbits_int(&p->p_flag, P_WAITED);
 			retval[0] = p->p_pid;
 
 			if (SCARG(uap, status)) {
@@ -535,7 +535,7 @@ loop:
 			return (error);
 		}
 		if ((SCARG(uap, options) & WCONTINUED) && (p->p_flag & P_CONTINUED)) {
-			p->p_flag &= ~P_CONTINUED;
+			atomic_clearbits_int(&p->p_flag, P_CONTINUED);
 			retval[0] = p->p_pid;
 
 			if (SCARG(uap, status)) {
diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c
index daa1303487a..d19608d9cbc 100644
--- a/sys/kern/kern_fork.c
+++ b/sys/kern/kern_fork.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_fork.c,v 1.86 2007/01/17 13:51:52 mickey Exp $	*/
+/*	$OpenBSD: kern_fork.c,v 1.87 2007/03/15 10:22:30 art Exp $	*/
 /*	$NetBSD: kern_fork.c,v 1.29 1996/02/09 18:59:34 christos Exp $	*/
 
 /*
@@ -238,9 +238,9 @@ fork1(struct proc *p1, int exitsig, int flags, void *stack, size_t stacksize,
 	p2->p_emul = p1->p_emul;
 	if (p1->p_flag & P_PROFIL)
 		startprofclock(p2);
-	p2->p_flag |= (p1->p_flag & (P_SUGID | P_SUGIDEXEC));
+	atomic_setbits_int(&p2->p_flag, p1->p_flag & (P_SUGID | P_SUGIDEXEC));
 	if (flags & FORK_PTRACE)
-		p2->p_flag |= (p1->p_flag & P_TRACED);
+		atomic_setbits_int(&p2->p_flag, p1->p_flag & P_TRACED);
 	p2->p_cred = pool_get(&pcred_pool, PR_WAITOK);
 	bcopy(p1->p_cred, p2->p_cred, sizeof(*p2->p_cred));
 	p2->p_cred->p_refcnt = 1;
@@ -272,17 +272,17 @@ fork1(struct proc *p1, int exitsig, int flags, void *stack, size_t stacksize,
 	}
 
 	if (p1->p_session->s_ttyvp != NULL && p1->p_flag & P_CONTROLT)
-		p2->p_flag |= P_CONTROLT;
+		atomic_setbits_int(&p2->p_flag, P_CONTROLT);
 	if (flags & FORK_PPWAIT)
-		p2->p_flag |= P_PPWAIT;
+		atomic_setbits_int(&p2->p_flag, P_PPWAIT);
 	p2->p_pptr = p1;
 	if (flags & FORK_NOZOMBIE)
-		p2->p_flag |= P_NOZOMBIE;
+		atomic_setbits_int(&p2->p_flag, P_NOZOMBIE);
 	LIST_INIT(&p2->p_children);
 
 #ifdef RTHREADS
 	if (flags & FORK_THREAD) {
-		p2->p_flag |= P_THREAD;
+		atomic_setbits_int(&p2->p_flag, P_THREAD);
 		p2->p_thrparent = p1->p_thrparent;
 	} else {
 		p2->p_thrparent = p2;
diff --git a/sys/kern/kern_kthread.c b/sys/kern/kern_kthread.c
index e60176d611d..8452426fbc7 100644
--- a/sys/kern/kern_kthread.c
+++ b/sys/kern/kern_kthread.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_kthread.c,v 1.26 2006/11/29 12:24:17 miod Exp $	*/
+/*	$OpenBSD: kern_kthread.c,v 1.27 2007/03/15 10:22:30 art Exp $	*/
 /*	$NetBSD: kern_kthread.c,v 1.3 1998/12/22 21:21:36 kleink Exp $	*/
 
 /*-
@@ -83,7 +83,7 @@ kthread_create(void (*func)(void *), void *arg,
 	/*
 	 * Mark it as a system process.
 	 */
-	p2->p_flag |= P_SYSTEM;
+	atomic_setbits_int(&p2->p_flag, P_SYSTEM);
 
 	/* Name it as specified. */
 	va_start(ap, fmt);
diff --git a/sys/kern/kern_lock.c b/sys/kern/kern_lock.c
index 1701c0ce7f2..d0b418a7b1f 100644
--- a/sys/kern/kern_lock.c
+++ b/sys/kern/kern_lock.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_lock.c,v 1.24 2007/02/14 00:53:48 jsg Exp $	*/
+/*	$OpenBSD: kern_lock.c,v 1.25 2007/03/15 10:22:30 art Exp $	*/
 
 /* 
  * Copyright (c) 1995
@@ -900,13 +900,13 @@ _kernel_proc_lock(struct proc *p)
 {
 	SCHED_ASSERT_UNLOCKED();
 	__mp_lock(&kernel_lock);
-	p->p_flag |= P_BIGLOCK;
+	atomic_setbits_int(&p->p_flag, P_BIGLOCK);
 }
 
 void
 _kernel_proc_unlock(struct proc *p)
 {
-	p->p_flag &= ~P_BIGLOCK;
+	atomic_clearbits_int(&p->p_flag, P_BIGLOCK);
 	__mp_unlock(&kernel_lock);
 }
 
diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c
index 5a11b8f6202..46b416d8507 100644
--- a/sys/kern/kern_proc.c
+++ b/sys/kern/kern_proc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_proc.c,v 1.31 2005/12/22 06:55:03 tedu Exp $	*/
+/*	$OpenBSD: kern_proc.c,v 1.32 2007/03/15 10:22:30 art Exp $	*/
 /*	$NetBSD: kern_proc.c,v 1.14 1996/02/09 18:59:41 christos Exp $	*/
 
 /*
@@ -230,7 +230,7 @@ enterpgrp(struct proc *p, pid_t pgid, int mksess)
 			sess->s_ttyp = NULL;
 			bcopy(p->p_session->s_login, sess->s_login,
 			    sizeof(sess->s_login));
-			p->p_flag &= ~P_CONTROLT;
+			atomic_clearbits_int(&p->p_flag, P_CONTROLT);
 			pgrp->pg_session = sess;
 #ifdef DIAGNOSTIC
 			if (p != curproc)
diff --git a/sys/kern/kern_prot.c b/sys/kern/kern_prot.c
index f3081e33740..f9e195364e9 100644
--- a/sys/kern/kern_prot.c
+++ b/sys/kern/kern_prot.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_prot.c,v 1.28 2005/12/03 18:09:08 tedu Exp $	*/
+/*	$OpenBSD: kern_prot.c,v 1.29 2007/03/15 10:22:30 art Exp $	*/
 /*	$NetBSD: kern_prot.c,v 1.33 1996/02/09 18:59:42 christos Exp $	*/
 
 /*
@@ -391,7 +391,7 @@ sys_setresuid(struct proc *p, void *v, register_t *retval)
 	if (suid != (uid_t)-1 && suid != pc->p_svuid)
 		pc->p_svuid = suid;
 
-	p->p_flag |= P_SUGID;
+	atomic_setbits_int(&p->p_flag, P_SUGID);
 	return (0);
 }
 
@@ -485,7 +485,7 @@ sys_setresgid(struct proc *p, void *v, register_t *retval)
 	if (sgid != (gid_t)-1)
 		pc->p_svgid = sgid;
 
-	p->p_flag |= P_SUGID;
+	atomic_setbits_int(&p->p_flag, P_SUGID);
 	return (0);
 }
 
@@ -594,7 +594,7 @@ sys_setuid(struct proc *p, void *v, register_t *retval)
 	 */
 	pc->pc_ucred = crcopy(pc->pc_ucred);
 	pc->pc_ucred->cr_uid = uid;
-	p->p_flag |= P_SUGID;
+	atomic_setbits_int(&p->p_flag, P_SUGID);
 	return (0);
 }
 
@@ -623,7 +623,7 @@ sys_seteuid(struct proc *p, void *v, register_t *retval)
 	 */
 	pc->pc_ucred = crcopy(pc->pc_ucred);
 	pc->pc_ucred->cr_uid = euid;
-	p->p_flag |= P_SUGID;
+	atomic_setbits_int(&p->p_flag, P_SUGID);
 	return (0);
 }
 
@@ -662,7 +662,7 @@ sys_setgid(struct proc *p, void *v, register_t *retval)
 	 */
 	pc->pc_ucred = crcopy(pc->pc_ucred);
 	pc->pc_ucred->cr_gid = gid;
-	p->p_flag |= P_SUGID;
+	atomic_setbits_int(&p->p_flag, P_SUGID);
 	return (0);
 }
 
@@ -691,7 +691,7 @@ sys_setegid(struct proc *p, void *v, register_t *retval)
 	 */
 	pc->pc_ucred = crcopy(pc->pc_ucred);
 	pc->pc_ucred->cr_gid = egid;
-	p->p_flag |= P_SUGID;
+	atomic_setbits_int(&p->p_flag, P_SUGID);
 	return (0);
 }
 
@@ -718,7 +718,7 @@ sys_setgroups(struct proc *p, void *v, register_t *retval)
 	if (error)
 		return (error);
 	pc->pc_ucred->cr_ngroups = ngrp;
-	p->p_flag |= P_SUGID;
+	atomic_setbits_int(&p->p_flag, P_SUGID);
 	return (0);
 }
 
diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index acc868830d8..43691c0c4c9 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_sig.c,v 1.87 2007/02/06 18:42:37 art Exp $	*/
+/*	$OpenBSD: kern_sig.c,v 1.88 2007/03/15 10:22:30 art Exp $	*/
 /*	$NetBSD: kern_sig.c,v 1.54 1996/04/22 01:38:32 christos Exp $	*/
 
 /*
@@ -288,9 +288,9 @@ setsigvec(struct proc *p, int signum, struct sigaction *sa)
 	ps->ps_catchmask[signum] = sa->sa_mask &~ sigcantmask;
 	if (signum == SIGCHLD) {
 		if (sa->sa_flags & SA_NOCLDSTOP)
-			p->p_flag |= P_NOCLDSTOP;
+			atomic_setbits_int(&p->p_flag, P_NOCLDSTOP);
 		else
-			p->p_flag &= ~P_NOCLDSTOP;
+			atomic_clearbits_int(&p->p_flag, P_NOCLDSTOP);
 		/*
 		 * If the SA_NOCLDWAIT flag is set or the handler
 		 * is SIG_IGN we reparent the dying child to PID 1
@@ -300,9 +300,9 @@ setsigvec(struct proc *p, int signum, struct sigaction *sa)
 		 */
 		if (p->p_pid != 1 && ((sa->sa_flags & SA_NOCLDWAIT) ||
 		    sa->sa_handler == SIG_IGN))
-			p->p_flag |= P_NOCLDWAIT;
+			atomic_setbits_int(&p->p_flag, P_NOCLDWAIT);
 		else
-			p->p_flag &= ~P_NOCLDWAIT;
+			atomic_clearbits_int(&p->p_flag, P_NOCLDWAIT);
 	}
 	if ((sa->sa_flags & SA_RESETHAND) != 0)
 		ps->ps_sigreset |= bit;
@@ -403,7 +403,7 @@ execsigs(struct proc *p)
 	ps->ps_sigstk.ss_size = 0;
 	ps->ps_sigstk.ss_sp = 0;
 	ps->ps_flags = 0;
-	p->p_flag &= ~P_NOCLDWAIT;
+	atomic_clearbits_int(&p->p_flag, P_NOCLDWAIT);
 	if (ps->ps_sigact[SIGCHLD] == SIG_IGN)
 		ps->ps_sigact[SIGCHLD] = SIG_DFL;
 }
@@ -851,7 +851,7 @@ psignal(struct proc *p, int signum)
 			psignal(q, signum);
 #endif
 		atomic_clearbits_int(&p->p_siglist, contsigmask);
-		p->p_flag &= ~P_CONTINUED;
+		atomic_clearbits_int(&p->p_flag, P_CONTINUED);
 	}
 
 	atomic_setbits_int(&p->p_siglist, mask);
@@ -942,7 +942,7 @@ psignal(struct proc *p, int signum)
 			 * an event, then it goes back to run state.
 			 * Otherwise, process goes back to sleep state.
 			 */
-			p->p_flag |= P_CONTINUED;
+			atomic_setbits_int(&p->p_flag, P_CONTINUED);
 			wakeup(p->p_pptr);
 			if (action == SIG_DFL)
 				atomic_clearbits_int(&p->p_siglist, mask);
@@ -1159,7 +1159,7 @@ proc_stop(struct proc *p)
 #endif
 
 	p->p_stat = SSTOP;
-	p->p_flag &= ~P_WAITED;
+	atomic_clearbits_int(&p->p_flag, P_WAITED);
 	wakeup(p->p_pptr);
 }
 
@@ -1279,7 +1279,7 @@ void
 sigexit(struct proc *p, int signum)
 {
 	/* Mark process as going away */
-	p->p_flag |= P_WEXIT;
+	atomic_setbits_int(&p->p_flag, P_WEXIT);
 
 	p->p_acflag |= AXSIG;
 	if (sigprop[signum] & SA_CORE) {
diff --git a/sys/kern/kern_synch.c b/sys/kern/kern_synch.c
index ae237fb2c92..22dd6d31f55 100644
--- a/sys/kern/kern_synch.c
+++ b/sys/kern/kern_synch.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_synch.c,v 1.75 2006/11/29 12:24:17 miod Exp $	*/
+/*	$OpenBSD: kern_synch.c,v 1.76 2007/03/15 10:22:30 art Exp $	*/
 /*	$NetBSD: kern_synch.c,v 1.37 1996/04/22 01:38:37 christos Exp $	*/
 
 /*
@@ -174,7 +174,7 @@ ltsleep(void *ident, int priority, const char *wmesg, int timo,
 	 * stopped, p->p_wchan will be 0 upon return from CURSIG.
 	 */
 	if (catch) {
-		p->p_flag |= P_SINTR;
+		atomic_setbits_int(&p->p_flag, P_SINTR);
 		if ((sig = CURSIG(p)) != 0) {
 			if (p->p_wchan)
 				unsleep(p);
@@ -204,9 +204,9 @@ resume:
 #else
 	curpriority = p->p_usrpri;
 #endif
-	p->p_flag &= ~P_SINTR;
+	atomic_clearbits_int(&p->p_flag, P_SINTR);
 	if (p->p_flag & P_TIMEOUT) {
-		p->p_flag &= ~P_TIMEOUT;
+		atomic_clearbits_int(&p->p_flag, P_TIMEOUT);
 		if (sig == 0) {
 #ifdef KTRACE
 			if (KTRPOINT(p, KTR_CSW))
@@ -258,7 +258,7 @@ endtsleep(void *arg)
 			setrunnable(p);
 		else
 			unsleep(p);
-		p->p_flag |= P_TIMEOUT;
+		atomic_setbits_int(&p->p_flag, P_TIMEOUT);
 	}
 	SCHED_UNLOCK(s);
 }
diff --git a/sys/kern/subr_prof.c b/sys/kern/subr_prof.c
index e12fee6d5d1..c5ca33402ee 100644
--- a/sys/kern/subr_prof.c
+++ b/sys/kern/subr_prof.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: subr_prof.c,v 1.16 2006/12/24 20:28:43 miod Exp $	*/
+/*	$OpenBSD: subr_prof.c,v 1.17 2007/03/15 10:22:30 art Exp $	*/
 /*	$NetBSD: subr_prof.c,v 1.12 1996/04/22 01:38:50 christos Exp $	*/
 
 /*-
@@ -201,6 +201,7 @@ addupc_intr(struct proc *p, u_long pc)
 
 	prof->pr_addr = pc;
 	prof->pr_ticks++;
+	atomic_setbits_int(&p->p_flag, P_OWEUPC);
 	need_proftick(p);
 }
 
diff --git a/sys/kern/sys_generic.c b/sys/kern/sys_generic.c
index 7192990a2b0..31cbafefff7 100644
--- a/sys/kern/sys_generic.c
+++ b/sys/kern/sys_generic.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sys_generic.c,v 1.54 2006/04/15 20:02:19 miod Exp $	*/
+/*	$OpenBSD: sys_generic.c,v 1.55 2007/03/15 10:22:30 art Exp $	*/
 /*	$NetBSD: sys_generic.c,v 1.24 1996/03/29 00:25:32 cgd Exp $	*/
 
 /*
@@ -684,7 +684,7 @@ sys_select(struct proc *p, void *v, register_t *retval)
 
 retry:
 	ncoll = nselcoll;
-	p->p_flag |= P_SELECT;
+	atomic_setbits_int(&p->p_flag, P_SELECT);
 	error = selscan(p, pibits[0], pobits[0], nd, ni, retval);
 	if (error || *retval)
 		goto done;
@@ -702,13 +702,13 @@ retry:
 		splx(s);
 		goto retry;
 	}
-	p->p_flag &= ~P_SELECT;
+	atomic_clearbits_int(&p->p_flag, P_SELECT);
 	error = tsleep(&selwait, PSOCK | PCATCH, "select", timo);
 	splx(s);
 	if (error == 0)
 		goto retry;
 done:
-	p->p_flag &= ~P_SELECT;
+	atomic_clearbits_int(&p->p_flag, P_SELECT);
 	/* select is not restarted after signals... */
 	if (error == ERESTART)
 		error = EINTR;
@@ -820,7 +820,7 @@ selwakeup(struct selinfo *sip)
 			else
 				unsleep(p);
 		} else if (p->p_flag & P_SELECT)
-			p->p_flag &= ~P_SELECT;
+			atomic_clearbits_int(&p->p_flag, P_SELECT);
 		SCHED_UNLOCK(s);
 	}
 }
@@ -907,7 +907,7 @@ sys_poll(struct proc *p, void *v, register_t *retval)
 
 retry:
 	ncoll = nselcoll;
-	p->p_flag |= P_SELECT;
+	atomic_setbits_int(&p->p_flag, P_SELECT);
 	pollscan(p, pl, nfds, retval);
 	if (*retval)
 		goto done;
@@ -925,14 +925,14 @@ retry:
 		splx(s);
 		goto retry;
 	}
-	p->p_flag &= ~P_SELECT;
+	atomic_clearbits_int(&p->p_flag, P_SELECT);
 	error = tsleep(&selwait, PSOCK | PCATCH, "poll", timo);
 	splx(s);
 	if (error == 0)
 		goto retry;
 
 done:
-	p->p_flag &= ~P_SELECT;
+	atomic_clearbits_int(&p->p_flag, P_SELECT);
 	/*
 	 * NOTE: poll(2) is not restarted after a signal and EWOULDBLOCK is
 	 *       ignored (since the whole point is to see what would block).
diff --git a/sys/kern/sys_process.c b/sys/kern/sys_process.c
index e60ff8b7ef7..188c581983d 100644
--- a/sys/kern/sys_process.c
+++ b/sys/kern/sys_process.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sys_process.c,v 1.37 2006/11/29 12:24:18 miod Exp $	*/
+/*	$OpenBSD: sys_process.c,v 1.38 2007/03/15 10:22:30 art Exp $	*/
 /*	$NetBSD: sys_process.c,v 1.55 1996/05/15 06:17:47 tls Exp $	*/
 
 /*-
@@ -231,7 +231,7 @@ sys_ptrace(struct proc *p, void *v, register_t *retval)
 	switch (SCARG(uap, req)) {
 	case  PT_TRACE_ME:
 		/* Just set the trace flag. */
-		SET(t->p_flag, P_TRACED);
+		atomic_setbits_int(&t->p_flag, P_TRACED);
 		t->p_oppid = t->p_pptr->p_pid;
 		if (t->p_ptstat == NULL)
 			t->p_ptstat = malloc(sizeof(*t->p_ptstat),
@@ -373,7 +373,7 @@ sys_ptrace(struct proc *p, void *v, register_t *retval)
 
 		/* not being traced any more */
 		t->p_oppid = 0;
-		CLR(t->p_flag, P_TRACED|P_WAITED);
+		atomic_clearbits_int(&t->p_flag, P_TRACED|P_WAITED);
 
 	sendsig:
 		bzero(t->p_ptstat, sizeof(*t->p_ptstat));
@@ -408,7 +408,7 @@ sys_ptrace(struct proc *p, void *v, register_t *retval)
 		 *   proc gets to see all the action.
 		 * Stop the target.
 		 */
-		SET(t->p_flag, P_TRACED);
+		atomic_setbits_int(&t->p_flag, P_TRACED);
 		t->p_oppid = t->p_pptr->p_pid;
 		if (t->p_pptr != p)
 			proc_reparent(t, p);
diff --git a/sys/kern/tty.c b/sys/kern/tty.c
index c6c94bcbfff..5a8c65440c0 100644
--- a/sys/kern/tty.c
+++ b/sys/kern/tty.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tty.c,v 1.71 2006/06/17 00:47:16 deraadt Exp $	*/
+/*	$OpenBSD: tty.c,v 1.72 2007/03/15 10:22:30 art Exp $	*/
 /*	$NetBSD: tty.c,v 1.68.4.2 1996/06/06 16:04:52 thorpej Exp $	*/
 
 /*-
@@ -987,7 +987,7 @@ ttioctl(struct tty *tp, u_long cmd, caddr_t data, int flag, struct proc *p)
 		tp->t_session = p->p_session;
 		tp->t_pgrp = p->p_pgrp;
 		p->p_session->s_ttyp = tp;
-		p->p_flag |= P_CONTROLT;
+		atomic_setbits_int(&p->p_flag, P_CONTROLT);
 		break;
 	case TIOCSPGRP: {		/* set pgrp of tty */
 		struct pgrp *pgrp = pgfind(*(int *)data);
diff --git a/sys/kern/tty_tty.c b/sys/kern/tty_tty.c
index 8723c197c41..e2a4b4accbb 100644
--- a/sys/kern/tty_tty.c
+++ b/sys/kern/tty_tty.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tty_tty.c,v 1.9 2005/12/21 12:43:49 jsg Exp $	*/
+/*	$OpenBSD: tty_tty.c,v 1.10 2007/03/15 10:22:30 art Exp $	*/
 /*	$NetBSD: tty_tty.c,v 1.13 1996/03/30 22:24:46 christos Exp $	*/
 
 /*-
@@ -119,7 +119,7 @@ cttyioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p)
 		return (EINVAL);
 	if (cmd == TIOCNOTTY) {
 		if (!SESS_LEADER(p)) {
-			p->p_flag &= ~P_CONTROLT;
+			atomic_clearbits_int(&p->p_flag, P_CONTROLT);
 			return (0);
 		} else
 			return (EINVAL);
diff --git a/sys/miscfs/procfs/procfs_ctl.c b/sys/miscfs/procfs/procfs_ctl.c
index 917691eb0f9..6644edb495b 100644
--- a/sys/miscfs/procfs/procfs_ctl.c
+++ b/sys/miscfs/procfs/procfs_ctl.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: procfs_ctl.c,v 1.19 2006/11/29 12:24:18 miod Exp $	*/
+/*	$OpenBSD: procfs_ctl.c,v 1.20 2007/03/15 10:22:30 art Exp $	*/
 /*	$NetBSD: procfs_ctl.c,v 1.14 1996/02/09 22:40:48 christos Exp $	*/
 
 /*
@@ -137,7 +137,7 @@ procfs_control(curp, p, op)
 		 *   proc gets to see all the action.
 		 * Stop the target.
 		 */
-		p->p_flag |= P_TRACED;
+		atomic_setbits_int(&p->p_flag, P_TRACED);
 		p->p_xstat = 0;		/* XXX ? */
 		if (p->p_pptr != curp) {
 			p->p_oppid = p->p_pptr->p_pid;
@@ -186,7 +186,7 @@ procfs_control(curp, p, op)
 			return (0);
 
 		/* not being traced any more */
-		CLR(p->p_flag, P_TRACED);
+		atomic_clearbits_int(&p->p_flag, P_TRACED);
 
 		/* give process back to original parent */
 		if (p->p_oppid != p->p_pptr->p_pid) {
@@ -198,7 +198,7 @@ procfs_control(curp, p, op)
 		}
 
 		p->p_oppid = 0;
-		CLR(p->p_flag, P_WAITED); /* XXX ? */
+		atomic_clearbits_int(&p->p_flag, P_WAITED);
 		wakeup(curp);	/* XXX for CTL_WAIT below ? */
 
 		break;
diff --git a/sys/sys/resourcevar.h b/sys/sys/resourcevar.h
index 11c18faab39..a50c7cb87c2 100644
--- a/sys/sys/resourcevar.h
+++ b/sys/sys/resourcevar.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: resourcevar.h,v 1.10 2006/12/24 20:28:44 miod Exp $	*/
+/*	$OpenBSD: resourcevar.h,v 1.11 2007/03/15 10:22:30 art Exp $	*/
 /*	$NetBSD: resourcevar.h,v 1.12 1995/11/22 23:01:53 cgd Exp $	*/
 
 /*
@@ -81,6 +81,7 @@ struct plimit {
 /* add user profiling from AST */
 #define	ADDUPROF(p)							\
 do {									\
+	atomic_clearbits_int(&(p)->p_flag, P_OWEUPC);			\
 	addupc_task((p), (p)->p_stats->p_prof.pr_addr,			\
 	    (p)->p_stats->p_prof.pr_ticks);				\
 	(p)->p_stats->p_prof.pr_ticks = 0;				\
diff --git a/sys/ufs/ffs/ffs_softdep.c b/sys/ufs/ffs/ffs_softdep.c
index 81460018e82..52b56f7bdba 100644
--- a/sys/ufs/ffs/ffs_softdep.c
+++ b/sys/ufs/ffs/ffs_softdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ffs_softdep.c,v 1.83 2007/02/04 10:36:05 pedro Exp $	*/
+/*	$OpenBSD: ffs_softdep.c,v 1.84 2007/03/15 10:22:30 art Exp $	*/
 
 /*
  * Copyright 1998, 2000 Marshall Kirk McKusick. All Rights Reserved.
@@ -5285,12 +5285,12 @@ request_cleanup(resource, islocked)
 	 * to avoid recursively processing the worklist.
 	 */
 	if (num_on_worklist > max_softdeps / 10) {
-		p->p_flag |= P_SOFTDEP;
+		atomic_setbits_int(&p->p_flag, P_SOFTDEP);
 		if (islocked)
 			FREE_LOCK(&lk);
 		process_worklist_item(NULL, LK_NOWAIT);
 		process_worklist_item(NULL, LK_NOWAIT);
-		p->p_flag &= ~P_SOFTDEP;
+		atomic_clearbits_int(&p->p_flag, P_SOFTDEP);
 		stat_worklist_push += 2;
 		if (islocked)
 			ACQUIRE_LOCK(&lk);