Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 3 Jul 2002 12:04:52 -0700 (PDT)
From:      Frank Mayhar <frank@exit.com>
To:        Shadow <shadow@gti.net>
Cc:        frank@exit.com, stable@FreeBSD.ORG
Subject:   Re: Status of fxp / smp problem?
Message-ID:  <200207031904.g63J4qqB073913@realtime.exit.com>
In-Reply-To: <035a01c222c3$f35fe3b0$fd01a8c0@getlost>

next in thread | previous in thread | raw e-mail | index | archive | help
Shadow wrote:
> Frank Mayhar wrote:
> > I have been one of the people suffering from the "intermittent-hang"
> > problem, with occasional hard freezes requiring a reset.  Well, it
> > appears that the problem has disappeared.  With a June 17 kernel
> > (although the installed /kernel says June 23, so it's _somewhere_ in
> > there) the problems, intermittent hangs and hard freezes, are gone
> > completely.  I've reinstalled dnetc and will be rerunning it, but as
> > I've been banging the CPUs heavily with video processing, I don't
> > expect a problem.
> Anybody have any info on this?  Have a production 4.6 with the bug (also
> appearing on xl driver) and would like to kludge the changes manually w/o
> having to cvsup.
> 
> What was the problem fineally traced to?  Anyone?

Reinstalling dnetc and rerunning it (on one or both CPUs) reintroduced the
"intermittent-hang" problem.  After reflection, I realized that the difference
between the video processing and the dnetc processing is that the former
spends quite a lot of time in the kernel (from a tenth to up to half of the
CPU time is 'system'), whereas the dnetc processing is entirely is in
userland.

What this indicates to me is that there may well be an end-of-quantum
context-switch problem with respect to interrupts.

So the problem is still extant; I'm just managing to avoid it for the
most part.  I've had no hard hangs requiring a reboot in over ten days,
now.
-- 
Frank Mayhar frank@exit.com	http://www.exit.com/
Exit Consulting                 http://www.gpsclock.com/

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-stable" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200207031904.g63J4qqB073913>