Messages in this thread | | | Date | Wed, 20 Aug 1997 10:58:42 +0200 (MET DST) | From | Ingo Molnar <> | Subject | Re: pre6+sw_raid freezes |
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On Tue, 19 Aug 1997, Bradley Ward Allen wrote:
> >Nevertheless, 2.1 freezes can be cleanly debugged via the 'ktrace' patch [...]
> Does this work with cold freezes? I mean, 0-degree-kelvin cold (no > log messages, no drive syncs, no LED light response, no packet > response, nothing)? [...]
yeah, i've debugged cold EIDE PCI freezes with this feature.
it's pretty simple: it prints a log onto the _text screen_, without scrolling of course, and by directly writing into video memory. The ringlog will run pretty fast, system will be slower, but it works. If now a cold freeze happens, all output will suddenly stop. So you've simply got to write down the log from the screen, where the kernel was when the lockup happened ;)
-- mingo
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