Dear sunmanagers,
My original posting:
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-
- Dear Sun-managers.
-
- Today, my SUN 470-server, running SunOS 4.1.3 went
- down with the laconic message 'panic: swtch'.
-
- What does it mean, and how to avoid it ??
-
-
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Thanks to miked@fujitsu.oz.au,
Kevin.Sheehan@uniq.com.au
eparr@niner.gsscwest.com
Mike wrote:
$We chased intermittent occurrences of this on a 490 running 4.1.2 for
$months. Eventually Sun came though with patch 101134 (it was probably
$generated for our client). The description says the cause is
$serial port activity, but it was likely that in this case the cause was
$high volumes of garbage network activity. They had terminal servers
$with very long serial lines attached, and if terminals were powered off they'd
$start generating rubbish, which would cause the servers to automatically
$call the Sun. 101134 (or its pre-release version) definitely fixed a
$a problem in the context switching code."
Kevin:
$Well, I can help you with the first part at any rate. swtch is the
$"routine" that is called to do a context switch. In other words, you'll
$see it at the bottom of the call graph when you do a trace back of the
$kernel stack for a process. ($<traceall in adb -k for instance)
$
$A panic there means that something about the context it was about to
$unload or load was bogus, so it panic'ed.
$
$My guess is that there is a patch lurking somewhere with your name on it.
Eric Parr sent me a description of the patch:
$Patch-ID# 101134-03
$Keywords: point patch panic serial ports swtch
$Synopsis: SunOS 4.1.2, 4.1.3: point patch for rare panic due to
$serial port load
$
$Date: Aug/02/94
$
$Solaris Release: 1.1
$
$SunOS release: 4.1.2, 4.1.3, 4.1.3C...
etc.
I got hold of the patch, and hopefully that's it.
Thanks again mates !
Morten Krabbe Barfoed
Danish Space Research Institute phone: +45 42 88 22 77 (switch-board)
Gl. Lundtoftevej 7 phone: +45 45 87 40 77 - 161 (direct)
DK 2800 Lyngby FAX: +45 45 93 02 83
Denmark e-mail: morten@dsri.dk
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