[src/trunk]: src/sys/arch/sparc64 Merge want_ast check in userret() into trap...

[nakayama <nakayama%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/0de74eef8a3b
branches:  trunk
changeset: 748218:0de74eef8a3b
user:      nakayama <nakayama%NetBSD.org@localhost>
date:      Sat Oct 17 08:50:49 2009 +0000

description:
Merge want_ast check in userret() into trap handler, and repeat
preempt() call while want_resched is true.  While there remove
unnecessary #if 1.

This should fix a performance degradation of disk I/O on heavy load.

diffstat:

 sys/arch/sparc64/include/userret.h |  10 +---------
 sys/arch/sparc64/sparc64/trap.c    |  14 ++++++++------
 2 files changed, 9 insertions(+), 15 deletions(-)

diffs (61 lines):

diff -r 88971cd90784 -r 0de74eef8a3b sys/arch/sparc64/include/userret.h
--- a/sys/arch/sparc64/include/userret.h        Fri Oct 16 23:57:39 2009 +0000
+++ b/sys/arch/sparc64/include/userret.h        Sat Oct 17 08:50:49 2009 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: userret.h,v 1.8 2008/06/30 14:12:20 nakayama Exp $ */
+/*     $NetBSD: userret.h,v 1.9 2009/10/17 08:50:49 nakayama Exp $ */
 
 /*
  * Copyright (c) 1996-2002 Eduardo Horvath.  All rights reserved.
@@ -63,14 +63,6 @@
 
        mi_userret(l);
 
-       if (want_ast) {
-               want_ast = 0;
-               if (l->l_pflag & LP_OWEUPC) {
-                       l->l_pflag &= ~LP_OWEUPC;
-                       ADDUPROF(l);
-               }
-       }
-
        /*
         * If profiling, charge recent system time to the trapped pc.
         */
diff -r 88971cd90784 -r 0de74eef8a3b sys/arch/sparc64/sparc64/trap.c
--- a/sys/arch/sparc64/sparc64/trap.c   Fri Oct 16 23:57:39 2009 +0000
+++ b/sys/arch/sparc64/sparc64/trap.c   Sat Oct 17 08:50:49 2009 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: trap.c,v 1.157 2009/05/16 19:15:34 nakayama Exp $ */
+/*     $NetBSD: trap.c,v 1.158 2009/10/17 08:50:49 nakayama Exp $ */
 
 /*
  * Copyright (c) 1996-2002 Eduardo Horvath.  All rights reserved.
@@ -50,7 +50,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.157 2009/05/16 19:15:34 nakayama Exp $");
+__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.158 2009/10/17 08:50:49 nakayama Exp $");
 
 #include "opt_ddb.h"
 #include "opt_multiprocessor.h"
@@ -608,12 +608,14 @@
 #endif
 
        case T_AST:
-#if 1
-               if (want_resched)
+               if (l->l_pflag & LP_OWEUPC) {
+                       l->l_pflag &= ~LP_OWEUPC;
+                       ADDUPROF(l);
+               }
+               while (want_resched)
                        preempt();
                want_ast = 0;
-#endif
-               break;  /* the work is all in userret() */
+               break;
 
        case T_ILLINST:
        case T_INST_EXCEPT: