Don't grab the kernel biglock for syscalls marked SY_NOLOCK;

make the amd64 code a bit nicer and make the sparc64 match that.

tested by a few;
OK toby@, dlg@, kettenis@ (for the sparc64 part).

2 files changed, 31 insertions, 27 deletions

diff --git a/sys/arch/amd64/amd64/syscall.c b/sys/arch/amd64/amd64/syscall.c
index 0d4f036bc5e..f1e09c83bba 100644
--- a/sys/arch/amd64/amd64/syscall.c
+++ b/sys/arch/amd64/amd64/syscall.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: syscall.c,v 1.11 2007/12/01 16:20:07 art Exp $	*/
+/*	$OpenBSD: syscall.c,v 1.12 2008/04/07 16:21:26 thib Exp $	*/
 /*	$NetBSD: syscall.c,v 1.1 2003/04/26 18:39:32 fvdl Exp $	*/
 
 /*-
@@ -74,7 +74,7 @@ syscall(struct trapframe frame)
 	int nsys;
 	size_t argsize, argoff;
 	register_t code, args[9], rval[2], *argp;
-	int nolock;
+	int lock;
 
 	uvmexp.syscalls++;
 	p = curproc;
@@ -133,41 +133,36 @@ syscall(struct trapframe frame)
 		}
 	}
 
-	nolock = (callp->sy_flags & SY_NOLOCK);
+	lock = !(callp->sy_flags & SY_NOLOCK);
 
-	if (!nolock)
-		KERNEL_PROC_LOCK(p);
 #ifdef SYSCALL_DEBUG
-	if (nolock)
-		KERNEL_PROC_LOCK(p);
+	KERNEL_PROC_LOCK(p);
 	scdebug_call(p, code, argp);
-	if (nolock)
-		KERNEL_PROC_UNLOCK(p);
+	KERNEL_PROC_UNLOCK(p);
 #endif
 #ifdef KTRACE
 	if (KTRPOINT(p, KTR_SYSCALL)) {
-		if (nolock)
-			KERNEL_PROC_LOCK(p);
+		KERNEL_PROC_LOCK(p);
 		ktrsyscall(p, code, callp->sy_argsize, argp);
-		if (nolock)
-			KERNEL_PROC_UNLOCK(p);
+		KERNEL_PROC_UNLOCK(p);
 	}
 #endif
-
 	rval[0] = 0;
 	rval[1] = frame.tf_rdx;
 #if NSYSTRACE > 0
 	if (ISSET(p->p_flag, P_SYSTRACE)) {
-		if (nolock)
-			KERNEL_PROC_LOCK(p);
+		KERNEL_PROC_LOCK(p);
 		error = systrace_redirect(code, p, argp, rval);
-		if (nolock)
-			KERNEL_PROC_UNLOCK(p);
+		KERNEL_PROC_UNLOCK(p);
 	} else
 #endif
+	{
+		if (lock)
+			KERNEL_PROC_LOCK(p);
 		error = (*callp->sy_call)(p, argp, rval);
-	if (!nolock)
-		KERNEL_PROC_UNLOCK(p);
+		if (lock)
+			KERNEL_PROC_UNLOCK(p);
+	}
 	switch (error) {
 	case 0:
 		frame.tf_rax = rval[0];
diff --git a/sys/arch/sparc64/sparc64/trap.c b/sys/arch/sparc64/sparc64/trap.c
index ff81f1b4535..55fc52eb12b 100644
--- a/sys/arch/sparc64/sparc64/trap.c
+++ b/sys/arch/sparc64/sparc64/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.61 2008/03/26 22:07:23 kettenis Exp $	*/
+/*	$OpenBSD: trap.c,v 1.62 2008/04/07 16:21:26 thib Exp $	*/
 /*	$NetBSD: trap.c,v 1.73 2001/08/09 01:03:01 eeh Exp $ */
 
 /*
@@ -1261,7 +1261,7 @@ syscall(tf, code, pc)
 	int64_t *ap;
 	const struct sysent *callp;
 	struct proc *p;
-	int error = 0, new;
+	int error = 0, new, lock;
 	register_t args[8];
 	register_t rval[2];
 
@@ -1282,6 +1282,8 @@ syscall(tf, code, pc)
 	callp = p->p_emul->e_sysent;
 	nsys = p->p_emul->e_nsysent;
 
+	lock = !(callp->sy_flags & SY_NOLOCK);
+
 	/*
 	 * The first six system call arguments are in the six %o registers.
 	 * Any arguments beyond that are in the `argument extension' area
@@ -1352,20 +1354,27 @@ syscall(tf, code, pc)
 		goto bad;
 	}
 
-	KERNEL_PROC_LOCK(p);
 #ifdef SYSCALL_DEBUG
+	KERNEL_PROC_LOCK(p);
 	scdebug_call(p, code, args);
+	KERNEL_PROC_UNLOCK(p);
 #endif
 	rval[0] = 0;
 	rval[1] = tf->tf_out[1];
 #if NSYSTRACE > 0
-	if (ISSET(p->p_flag, P_SYSTRACE))
+	if (ISSET(p->p_flag, P_SYSTRACE)) {
+		KERNEL_PROC_LOCK(p);
 		error = systrace_redirect(code, p, args, rval);
-	else
+		KERNEL_PROC_UNLOCK(p);
+	} else
 #endif
+	{
+		if (lock)
+			KERNEL_PROC_LOCK(p);
 		error = (*callp->sy_call)(p, args, rval);
-	KERNEL_PROC_UNLOCK(p);
-
+		if (lock)
+			KERNEL_PROC_UNLOCK(p);
+	}
 	switch (error) {
 		vaddr_t dest;
 	case 0: