Date: Wed, 19 Aug 1998 16:45:36 +0000 From: Mike Smith <mike@smith.net.au> To: Brian Feldman <green@unixhelp.org> Cc: Bruce Evans <bde@zeta.org.au>, freebsd-current@FreeBSD.ORG, jwd@unx.sas.com Subject: Re: 13 months of user time? Message-ID: <199808191645.QAA03559@dingo.cdrom.com> In-Reply-To: Your message of "Wed, 19 Aug 1998 17:22:50 -0400." <Pine.BSF.4.02.9808191720490.29282-100000@zone.syracuse.net>
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At a guess, it's either in or related to this fragment from
kern/kern_synch.c:
/*
* Compute the amount of time during which the current
* process was running, and add that to its total so far.
*/
microuptime(&switchtime);
p->p_runtime += (switchtime.tv_usec - p->p_switchtime.tv_usec) +
(switchtime.tv_sec - p->p_switchtime.tv_sec) * (int64_t)1000000;
Either microuptime() is returning garbage, or the calculation is bogus.
> It's probably a good idea to get this fixed ASAP, since people have been
> complaining about this exact bug for months now. Would anyone like to give
> me any pointers to where to start evaluating the code at, or what
> functions this could be caused by? I think I'll check the process
> accounting code first then the actual timing code, if noone has any better
> ideas.
>
> Brian Feldman
> green@unixhelp.org
>
> On Thu, 20 Aug 1998, Bruce Evans wrote:
>
> > > I found this on a 3 month old snap, and have now replicated it
> > >on 3.0-980818-SNAP.
> > >
> > >for i in /bin/*; do
> > > time rsh nodename uptime
> > >done
> > >
> > > Yields the following output:
> > >
> > >.....
> > > 2:00PM up 1 day, 1:39, 1 user, load averages: 0.00, 0.00, 0.00
> > > 0.19s real 0.00s user 0.00s system
> > > 2:00PM up 1 day, 1:39, 1 user, load averages: 0.00, 0.00, 0.00
> > > 0.20s real 33554431.00s user 0.00s system
> >
> > This is probably just a symptom of a negative times bug and assorted
> > overflows. This negative times bug usually kills processes with a
> > SIGXCPU.
> >
> > Bruce
> >
> > To Unsubscribe: send mail to majordomo@FreeBSD.org
> > with "unsubscribe freebsd-current" in the body of the message
> >
>
>
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--
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