NetBSD Problem Report #26108

Received: (qmail 11275 invoked by uid 605); 29 Jun 2004 10:38:04 -0000
Message-Id: <1088504875.170548.6034.nullmailer@yamt.dyndns.org>
Date: Tue, 29 Jun 2004 19:27:55 +0900
From: yamt@mwd.biglobe.ne.jp
Sender: gnats-bugs-owner@NetBSD.org
Reply-To: yamt@mwd.biglobe.ne.jp
To: gnats-bugs@gnats.netbsd.org
Subject: losing ticks with MULTIPROCESSOR
X-Send-Pr-Version: 3.95

>Number:         26108
>Category:       kern
>Synopsis:       losing ticks with MULTIPROCESSOR
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          closed
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Jun 29 10:39:00 +0000 2004
>Closed-Date:    Wed Nov 28 06:14:45 +0000 2018
>Last-Modified:  Wed Nov 28 06:14:45 +0000 2018
>Originator:     YAMAMOTO Takashi <yamt@mwd.biglobe.ne.jp>
>Release:        NetBSD 2.0F
>Organization:

>Environment:


System: NetBSD kaeru 2.0F NetBSD 2.0F (build.kaeru) #1461: Tue Jun 29 16:56:46 JST 2004 takashi@kaeru:/home/takashi/work/kernel/build.kaeru i386
Architecture: i386
Machine: i386
>Description:
	as mi_switch() attempt to reacquire kernel_lock with higher IPL
	than IPL_CLOCK, ticks are frequently lost.
>How-To-Repeat:
	run on a multiprocessor box without ntpd.
>Fix:
	the following is a workaround.

Index: kern_synch.c
===================================================================
--- kern_synch.c	(revision 717)
+++ kern_synch.c	(working copy)
@@ -938,6 +938,7 @@ mi_switch(struct lwp *l, struct lwp *new
 		cpu_switchto(l, newl);
 		retval = 0;
 	}
+	spl0(); /* XXX */

 	/*
 	 * If we are using h/w performance counters, restore context.
@@ -968,6 +969,7 @@ mi_switch(struct lwp *l, struct lwp *new
 	 * we reacquire the interlock.
 	 */
 	KERNEL_LOCK_ACQUIRE_COUNT(hold_count);
+	(void)splsched(); /* XXX */

 	return retval;
 }
>Release-Note:
>Audit-Trail:
State-Changed-From-To: open->closed
State-Changed-By: maya@NetBSD.org
State-Changed-When: Wed, 28 Nov 2018 06:14:45 +0000
State-Changed-Why:
This code has changed a lot, and no longer uses KERNEL_LOCK. mrg believes it is fixed, and yamt asked to close it.


>Unformatted:

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