Re: Dumps on kernel panic

Drew Eckhardt (
Tue, 04 Jul 1995 22:18:54 -0600

In message <>,
>On system boot, allocate a fixed number of physical pages for preserving
>'important' data. Let's say 2Mb (yes, I propose this only as a configuration

The problem with this is how it affects the failure mode. Two megabytes
less memory on a system will mean it's swapping differently, using less
buffer cache, etc. If it's a disk driver or perhaps memory management
problem, it may not fail in the same way once the debugging is turned

>Here's the not-very cunning bit: Most PC's when you press the reset button
>do *not* clear memory. If they do, it's often the memory check that
>does it and BIOS initialisation, which often only affects the bottom
>megabyte, and even then not always that. If the PC memory checks above
>1Mb (which is normally determined by some BIOS word being 4321 or 1234
>or similar - all documented) then it will, admittedly, corrupt this
>area, but we can prevent this by setting the word appropriately which
>will fix us up the majority of case.

I've seen a fair number of flakey Linux systems which crap out when
they reboot, perhaps requiring a power cycle.

>Note you aren't getting memory for free - you are losing 2Mb of RAM. This
>option tush isn't going to suit everyone, but it might be a useful debugging

It has to suit average users, since they're the people who need it most. If
I can't reproduce your problem, and can't get a good idea what's happening
inside your machine, I'm not going to fix your problem.