Messages in this thread |  | | From | Keith Owens <> | Subject | Re: 2.4.0-test11pre2-ac1 and previous problem | Date | Sun, 12 Nov 2000 13:27:13 +1100 |
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On Sun, 12 Nov 2000 12:32:55 +1100, Andrew Morton <andrewm@uow.edu.au> wrote: >> > > NMI Watchdog detected LOCKUP on CPU3, registers: >That's a pretty wierd trace. You seem to have addresses related >to the `apm' kernel thread on mysqld's stack.
Normal unfortunately. Firstly the ix86 oops code just scans the stack and prints anything that looks like it might be a kernel address. It makes no attempt to confirm that these really are return addresses, so an ix86 oops trace gets lots of false positives. Secondly that trace was converted by klogd (symbols in call trace line instead of numbers) not by ksymoops, I do not trust the klogd algorithm at all. Between the false positives and the very real possibility of klogd having got it wrong, you have to take any ix86 oops with a pinch of salt.
Statrting klogd as "klogd -x" in /etc/rc.d/init.d/syslog will get rid of one source of error. Using the kdb patch[*] will give you a much better debug environment for NMI lockups. kdb gives an accurate back trace because it understands ix86 stack frames as well as the out of line lock handlers, at the expense of some very ugly code.
[*]ftp://oss.sgi.com/projects/kdb/download/ix86/
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