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

1 files changed, 2 insertions, 1 deletions

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,