From: art <art@openbsd.org>
Date: Fri, 18 Jul 2008 23:43:31 +0000 (+0000)
Subject: Add a macro that clears the want_resched flag that need_resched sets.
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=2c9d4ccbcf9b120efddf613d0ef0d6e5a35509ec;p=openbsd

Add a macro that clears the want_resched flag that need_resched sets.
Right now when mi_switch picks up the same proc, we didn't clear the
flag which would mean that every time we service an AST we would attempt
a context switch. For some architectures, amd64 being probably the
most extreme, that meant attempting to context switch for every
trap and interrupt.

Now we clear_resched explicitly after every context switch, even if it
didn't do anything. Which also allows us to remove some more code
in cpu_switchto (not done yet).

miod@ ok
---

diff --git a/sys/arch/alpha/include/cpu.h b/sys/arch/alpha/include/cpu.h
index 5937dbdd0d4..9e393ffc3d6 100644
--- a/sys/arch/alpha/include/cpu.h
+++ b/sys/arch/alpha/include/cpu.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: cpu.h,v 1.32 2008/06/26 05:42:08 ray Exp $ */
+/* $OpenBSD: cpu.h,v 1.33 2008/07/18 23:43:31 art Exp $ */
 /* $NetBSD: cpu.h,v 1.45 2000/08/21 02:03:12 thorpej Exp $ */
 
 /*-
@@ -282,12 +282,14 @@ do {									\
 	ci->ci_want_resched = 1;					\
 	aston(curcpu());						\
 } while (/*CONSTCOND*/0)
+#define clear_resched(ci) (ci)->ci_want_resched = 0
 #else
 #define	need_resched(ci)						\
 do {									\
 	curcpu()->ci_want_resched = 1;					\
 	aston(curcpu());						\
 } while (/*CONSTCOND*/0)
+#define clear_resched(ci) curcpu()->ci_want_resched = 0
 #endif
 
 /*
diff --git a/sys/arch/amd64/include/cpu.h b/sys/arch/amd64/include/cpu.h
index 2516fdd256b..248a9659c6e 100644
--- a/sys/arch/amd64/include/cpu.h
+++ b/sys/arch/amd64/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.36 2008/06/10 02:55:39 weingart Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.37 2008/07/18 23:43:31 art Exp $	*/
 /*	$NetBSD: cpu.h,v 1.1 2003/04/26 18:39:39 fvdl Exp $	*/
 
 /*-
@@ -161,6 +161,7 @@ extern struct cpu_info *cpu_info_list;
  * or after the current trap/syscall if in system mode.
  */
 extern void need_resched(struct cpu_info *);
+#define clear_resched(ci) (ci)->ci_want_resched = 0
 
 #if defined(MULTIPROCESSOR)
 
diff --git a/sys/arch/arm/include/cpu.h b/sys/arch/arm/include/cpu.h
index 9aa2166b1f2..0c418dcb21f 100644
--- a/sys/arch/arm/include/cpu.h
+++ b/sys/arch/arm/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.18 2007/08/14 15:18:07 deraadt Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.19 2008/07/18 23:43:31 art Exp $	*/
 /*	$NetBSD: cpu.h,v 1.34 2003/06/23 11:01:08 martin Exp $	*/
 
 /*
@@ -256,6 +256,7 @@ extern int astpending;
  */
 extern int want_resched;	/* resched() was called */
 #define	need_resched(ci)	(want_resched = 1, setsoftast())
+#define clear_resched(ci) 	want_resched = 0
 
 /*
  * Give a profiling tick to the current process when the user profiling
diff --git a/sys/arch/hp300/include/cpu.h b/sys/arch/hp300/include/cpu.h
index 76afb0a716c..a524d1cb618 100644
--- a/sys/arch/hp300/include/cpu.h
+++ b/sys/arch/hp300/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.35 2007/11/02 19:18:54 martin Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.36 2008/07/18 23:43:31 art Exp $	*/
 /*	$NetBSD: cpu.h,v 1.28 1998/02/13 07:41:51 scottr Exp $	*/
 
 /*
@@ -92,6 +92,7 @@ struct clockframe {
  */
 extern int want_resched;	/* resched() was called */
 #define	need_resched(ci)	{ want_resched = 1; aston(); }
+#define clear_resched(ci) 	want_resched = 0
 
 /*
  * Give a profiling tick to the current process when the user profiling
diff --git a/sys/arch/hppa/include/cpu.h b/sys/arch/hppa/include/cpu.h
index f4b45f47d30..d80bae1d2ed 100644
--- a/sys/arch/hppa/include/cpu.h
+++ b/sys/arch/hppa/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.53 2008/07/14 13:39:06 miod Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.54 2008/07/18 23:43:31 art Exp $	*/
 
 /*
  * Copyright (c) 2000-2004 Michael Shalayeff
@@ -151,6 +151,7 @@ extern register_t kpsw;
 
 #define	signotify(p)		(setsoftast())
 #define	need_resched(ci)	(want_resched = 1, setsoftast())
+#define clear_resched(ci) 	want_resched = 0
 #define	need_proftick(p)	setsoftast()
 #define	PROC_PC(p)		((p)->p_md.md_regs->tf_iioq_head)
 
diff --git a/sys/arch/hppa64/include/cpu.h b/sys/arch/hppa64/include/cpu.h
index ddc35e3be5b..b34705b425f 100644
--- a/sys/arch/hppa64/include/cpu.h
+++ b/sys/arch/hppa64/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.11 2007/05/16 19:37:06 thib Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.12 2008/07/18 23:43:31 art Exp $	*/
 
 /*
  * Copyright (c) 2005 Michael Shalayeff
@@ -196,6 +196,7 @@ extern int cpu_hvers;
 
 #define	signotify(p)		(setsoftast())
 #define	need_resched(ci)	(want_resched = 1, setsoftast())
+#define clear_resched(ci) 	want_resched = 0
 #define	need_proftick(p)	setsoftast()
 
 #ifndef _LOCORE
diff --git a/sys/arch/i386/include/cpu.h b/sys/arch/i386/include/cpu.h
index 7632dbb53ce..62209b1acb3 100644
--- a/sys/arch/i386/include/cpu.h
+++ b/sys/arch/i386/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.102 2008/06/09 20:43:43 miod Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.103 2008/07/18 23:43:31 art Exp $	*/
 /*	$NetBSD: cpu.h,v 1.35 1996/05/05 19:29:26 christos Exp $	*/
 
 /*-
@@ -230,6 +230,7 @@ extern void cpu_init_idle_pcbs(void);
  * or after the current trap/syscall if in system mode.
  */
 extern void need_resched(struct cpu_info *);
+#define clear_resched(ci) (ci)->ci_want_resched = 0
 
 #define	CLKF_USERMODE(frame)	USERMODE((frame)->if_cs, (frame)->if_eflags)
 #define	CLKF_PC(frame)		((frame)->if_eip)
diff --git a/sys/arch/m88k/include/cpu.h b/sys/arch/m88k/include/cpu.h
index aa3acd6438b..2e196920d8f 100644
--- a/sys/arch/m88k/include/cpu.h
+++ b/sys/arch/m88k/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.34 2008/01/13 20:20:29 miod Exp $ */
+/*	$OpenBSD: cpu.h,v 1.35 2008/07/18 23:43:31 art Exp $ */
 /*
  * Copyright (c) 1996 Nivas Madhur
  * Copyright (c) 1992, 1993
@@ -241,6 +241,7 @@ do {									\
 	if (ci->ci_curproc != NULL)					\
 		aston(ci->ci_curproc);					\
 } while (0)
+#define clear_resched(ci) 	(ci)->ci_want_resched = 0
 
 /*
  * Give a profiling tick to the current process when the user profiling
diff --git a/sys/arch/mac68k/include/cpu.h b/sys/arch/mac68k/include/cpu.h
index f3562fbdc94..4ad125df84b 100644
--- a/sys/arch/mac68k/include/cpu.h
+++ b/sys/arch/mac68k/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.46 2007/11/02 19:18:54 martin Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.47 2008/07/18 23:43:31 art Exp $	*/
 /*	$NetBSD: cpu.h,v 1.45 1997/02/10 22:13:40 scottr Exp $	*/
 
 /*
@@ -105,6 +105,7 @@ struct clockframe {
  */
 extern int want_resched;	/* resched() was called */
 #define	need_resched(ci)	{ want_resched = 1; aston(); }
+#define clear_resched(ci) 	want_resched = 0
 
 /*
  * Give a profiling tick to the current process from the softclock
diff --git a/sys/arch/mips64/include/cpu.h b/sys/arch/mips64/include/cpu.h
index d320ef5a309..3a5d6d96f78 100644
--- a/sys/arch/mips64/include/cpu.h
+++ b/sys/arch/mips64/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.24 2008/04/07 22:37:16 miod Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.25 2008/07/18 23:43:31 art Exp $	*/
 
 /*-
  * Copyright (c) 1992, 1993
@@ -409,6 +409,7 @@ extern int int_nest_cntr;
  * or after the current trap/syscall if in system mode.
  */
 #define	need_resched(info)	{ want_resched = 1; aston(); }
+#define clear_resched(ci) 	want_resched = 0
 
 /*
  * Give a profiling tick to the current process when the user profiling
diff --git a/sys/arch/mvme68k/include/cpu.h b/sys/arch/mvme68k/include/cpu.h
index 99f07c83839..727b8171e37 100644
--- a/sys/arch/mvme68k/include/cpu.h
+++ b/sys/arch/mvme68k/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.27 2007/05/30 17:10:44 miod Exp $ */
+/*	$OpenBSD: cpu.h,v 1.28 2008/07/18 23:43:31 art Exp $ */
 
 /*
  * Copyright (c) 1995 Theo de Raadt
@@ -115,6 +115,7 @@ struct clockframe {
  */
 extern int want_resched;
 #define	need_resched(ci)	{ want_resched = 1; aston(); }
+#define clear_resched(ci) 	want_resched = 0
 
 /*
  * Give a profiling tick to the current process when the user profiling
diff --git a/sys/arch/powerpc/include/cpu.h b/sys/arch/powerpc/include/cpu.h
index e95b065b37b..4a6d2ed2692 100644
--- a/sys/arch/powerpc/include/cpu.h
+++ b/sys/arch/powerpc/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.37 2008/05/04 20:54:22 drahn Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.38 2008/07/18 23:43:31 art Exp $	*/
 /*	$NetBSD: cpu.h,v 1.1 1996/09/30 16:34:21 ws Exp $	*/
 
 /*
@@ -151,6 +151,7 @@ do {									\
 	if (ci->ci_curproc != NULL)					\
 		aston(ci->ci_curproc);					\
 } while (0)
+#define clear_resched(ci) (ci)->ci_want_resched = 0
 
 #define	need_proftick(p)	aston(p)
 
diff --git a/sys/arch/sh/include/cpu.h b/sys/arch/sh/include/cpu.h
index 2b8a0d5d579..dd2cd3138d1 100644
--- a/sys/arch/sh/include/cpu.h
+++ b/sys/arch/sh/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.13 2008/05/21 19:45:37 miod Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.14 2008/07/18 23:43:31 art Exp $	*/
 /*	$NetBSD: cpu.h,v 1.41 2006/01/21 04:24:12 uwe Exp $	*/
 
 /*-
@@ -101,6 +101,7 @@ do {									\
 	if (curproc != NULL)						\
 		aston(curproc);					\
 } while (/*CONSTCOND*/0)
+#define clear_resched(ci) 	want_resched = 0
 
 /*
  * Give a profiling tick to the current process when the user profiling
diff --git a/sys/arch/sparc/include/cpu.h b/sys/arch/sparc/include/cpu.h
index 44686965093..5d44640212f 100644
--- a/sys/arch/sparc/include/cpu.h
+++ b/sys/arch/sparc/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.29 2007/05/08 07:23:18 art Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.30 2008/07/18 23:43:31 art Exp $	*/
 /*	$NetBSD: cpu.h,v 1.24 1997/03/15 22:25:15 pk Exp $ */
 
 /*
@@ -131,6 +131,7 @@ extern void	raise(int, int);
  */
 extern int	want_resched;		/* resched() was called */
 #define	need_resched(ci)		(want_resched = 1, want_ast = 1)
+#define clear_resched(ci) 	want_resched = 0
 extern int	want_ast;
 
 /*
diff --git a/sys/arch/sparc64/include/cpu.h b/sys/arch/sparc64/include/cpu.h
index 709165826e1..a6251debd25 100644
--- a/sys/arch/sparc64/include/cpu.h
+++ b/sys/arch/sparc64/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.62 2008/07/04 22:03:30 kettenis Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.63 2008/07/18 23:43:31 art Exp $	*/
 /*	$NetBSD: cpu.h,v 1.28 2001/06/14 22:56:58 thorpej Exp $ */
 
 /*
@@ -223,6 +223,7 @@ void setsoftnet(void);
  * or after the current trap/syscall if in system mode.
  */
 extern void need_resched(struct cpu_info *);
+#define clear_resched(ci) (ci)->ci_want_resched = 0
 
 /*
  * This is used during profiling to integrate system time.
diff --git a/sys/arch/vax/include/cpu.h b/sys/arch/vax/include/cpu.h
index dc6ec203a16..4dc1b5a8654 100644
--- a/sys/arch/vax/include/cpu.h
+++ b/sys/arch/vax/include/cpu.h
@@ -1,4 +1,4 @@
-/*      $OpenBSD: cpu.h,v 1.26 2007/10/10 15:53:53 art Exp $      */
+/*      $OpenBSD: cpu.h,v 1.27 2008/07/18 23:43:31 art Exp $      */
 /*      $NetBSD: cpu.h,v 1.41 1999/10/21 20:01:36 ragge Exp $      */
 
 /*
@@ -107,6 +107,7 @@ extern int bootdev;
 	want_resched++; \
 	mtpr(AST_OK,PR_ASTLVL); \
 	}
+#define clear_resched(ci) 	want_resched = 0
 
 /*
  * Notify the current process (p) that it has a signal pending,
diff --git a/sys/kern/sched_bsd.c b/sys/kern/sched_bsd.c
index 2bfbadbec94..e7babbb88ed 100644
--- a/sys/kern/sched_bsd.c
+++ b/sys/kern/sched_bsd.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sched_bsd.c,v 1.16 2008/05/22 14:07:14 thib Exp $	*/
+/*	$OpenBSD: sched_bsd.c,v 1.17 2008/07/18 23:43:31 art Exp $	*/
 /*	$NetBSD: kern_synch.c,v 1.37 1996/04/22 01:38:37 christos Exp $	*/
 
 /*-
@@ -415,6 +415,8 @@ mi_switch(void)
 		p->p_stat = SONPROC;
 	}
 
+	clear_resched(curcpu());
+
 	SCHED_ASSERT_LOCKED();
 
 	/*