NetBSD Problem Report #15688
Received: (qmail 13954 invoked from network); 21 Feb 2002 19:48:59 -0000
Message-Id: <200202211948.g1LJmvu01113@night-porter.duskware.de>
Date: Thu, 21 Feb 2002 20:48:57 +0100 (MET)
From: Martin Husemann <martin@duskware.de>
Reply-To: martin@duskware.de
To: gnats-bugs@gnats.netbsd.org
Subject: p_stats->p_cru.ru_utime.tv_sec may become negative
X-Send-Pr-Version: 3.95
>Number: 15688
>Category: kern
>Synopsis: p_stats->p_cru.ru_utime.tv_sec may become negative
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: kern-bug-people
>State: closed
>Class: sw-bug
>Submitter-Id: net
>Arrival-Date: Thu Feb 21 19:50:03 +0000 2002
>Closed-Date: Sat May 13 17:37:05 +0000 2023
>Last-Modified: Sat May 13 17:37:05 +0000 2023
>Originator: Martin Husemann
>Release: NetBSD 1.5ZA
>Organization:
>Environment:
System: NetBSD night-porter.duskware.de 1.5ZA NetBSD 1.5ZA (PORTER) #0: Tue Feb 12 21:59:35 CET 2002 martin@insomnia.duskware.de:/usr/src/sys/arch/i386/compile/PORTER i386
Architecture: i386
Machine: i386
>Description:
When you step the time backwards (or have ntpd runing causing this, i.e. just
after booting a machine, on first sync to the next timeserver), processes
started before this step may get a negative cummulated child cpu time.
Example from my sparc64 system:
168 ?? S 0:-2.74 /usr/pkg/sbin/upsmon
This has been started just before ntpd, and ntpd did a few time resets
initially:
Feb 21 19:08:28 setting-sun ntpd[143]: time reset 5.511258 s
Feb 21 19:08:28 setting-sun ntpd[143]: kernel pll status change 41
Feb 21 19:28:51 setting-sun ntpd[143]: time reset 0.574144 s
Feb 21 19:49:19 setting-sun ntpd[143]: time reset 0.132181 s
I'm not sure fixing the scheduler to correctly handle this situation are
worth the additional context switch time.
>How-To-Repeat:
s/a
>Fix:
n/a
>Release-Note:
>Audit-Trail:
From: christos@zoulas.com (Christos Zoulas)
To: martin@duskware.de, kern-bug-people@netbsd.org,
gnats-bugs@gnats.netbsd.org,
gnats-admin@netbsd.org (GNATS Management)
Cc:
Subject: Re: kern/15688: p_stats->p_cru.ru_utime.tv_sec may become negative
Date: Thu, 21 Feb 2002 15:06:36 -0500
On Feb 21, 8:48pm, martin@duskware.de (Martin Husemann) wrote:
-- Subject: kern/15688: p_stats->p_cru.ru_utime.tv_sec may become negative
shouldn't process resources calculated using mono_time instead of microtime
in calcru()?
christos
| When you step the time backwards (or have ntpd runing causing this, i.e. just
| after booting a machine, on first sync to the next timeserver), processes
| started before this step may get a negative cummulated child cpu time.
|
| Example from my sparc64 system:
|
| 168 ?? S 0:-2.74 /usr/pkg/sbin/upsmon
|
| This has been started just before ntpd, and ntpd did a few time resets
| initially:
|
| Feb 21 19:08:28 setting-sun ntpd[143]: time reset 5.511258 s
| Feb 21 19:08:28 setting-sun ntpd[143]: kernel pll status change 41
| Feb 21 19:28:51 setting-sun ntpd[143]: time reset 0.574144 s
| Feb 21 19:49:19 setting-sun ntpd[143]: time reset 0.132181 s
|
| I'm not sure fixing the scheduler to correctly handle this situation are
| worth the additional context switch time.
|
| >How-To-Repeat:
| s/a
| >Fix:
| n/a
| >Release-Note:
| >Audit-Trail:
| >Unformatted:
-- End of excerpt from Martin Husemann
State-Changed-From-To: open->feedback
State-Changed-By: dholland@NetBSD.org
State-Changed-When: Sat, 13 May 2023 17:18:46 +0000
State-Changed-Why:
Is this still a thing?
State-Changed-From-To: feedback->closed
State-Changed-By: martin@NetBSD.org
State-Changed-When: Sat, 13 May 2023 17:37:05 +0000
State-Changed-Why:
Haven't seen it in years
>Unformatted:
(Contact us)
$NetBSD: query-full-pr,v 1.47 2022/09/11 19:34:41 kim Exp $
$NetBSD: gnats_config.sh,v 1.9 2014/08/02 14:16:04 spz Exp $
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