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Eric Myers
Eric Myers
Joined: 8 Nov 04
Posts: 45
Credit: 1349848
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Ageless wrote: I think we may

Message 82072 in response to message 82071

Ageless wrote:

I think we may need some more investigation into it.

Here's one thing I think would be helpful to assess the impact of this problem. Can we take a survey of Linux distros to see what preemption settings they use? I will even make some predictions, as I did above. I'll predict Ubuntu uses voluntary preemption, and Fedora turns it off. Prove me wrong.

- Eric Myers

Bikeman (Heinz-Bernd Eggenstein)
Bikeman (Heinz-...
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Joined: 28 Aug 06
Posts: 3522
Credit: 804818814
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Ok, signal 8 is just a

Message 82073 in response to message 82072

Ok, signal 8 is just a symptom, the reason can be many things: overclocking, undervolting, overheating, or, as in this case, a kernel bug resulting in FPU stack corruption.

I guess a FAQ entry should state that Linux kernels between 2.6.20 and probably 2.6.27 (or whatever kernel will get this fix) with CONFIG_PREEMPT=y have a certain bug that might trigger validation errors or signal 8 exceptions on any BOINC app (in fact all applications)

All other possible reasons like overclocking/undervolting/overheating seem to produce a mix of signal 8 and SIGSEGV segmentation faults (error code 99)

CU
Bikeman

Bikeman (Heinz-Bernd Eggenstein)
Bikeman (Heinz-...
Moderator
Joined: 28 Aug 06
Posts: 3522
Credit: 804818814
RAC: 1238198

Hi! The fix for the Linux

Hi!

The fix for the Linux kernel bug that was discovered when E@H kept failing under certain circumstances has now made it into kernel release candidate 2.6.26-rc5

http://thread.gmane.org/gmane.linux.kernel/690130

So if you have experienced frequent "signal 8" (error code 38) problems, are using a Linux kernel >= 2.6.20 and the kernel was compiled with the setting "CONFIG_PREEMPT=y" , you can either wait for the final release of kernel 2.6.26 (estimated to happen within the next couple of weeks) or try the 2.6.26-rc5 kernel version.

CU
Bikeman

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