Red Hat Bugzilla – Bug 14776
Floating point exceptions in kernel-2.2.16-3smp in RH6.2
Last modified: 2008-05-01 11:37:57 EDT
Having similar problem as reported in Bug# 10509, but am running from updates/6.2/i686/kernel-smp-2.2.16-3.i686.rpm. Lilo boots with no initrd (IDE boot disk). Seti@home processes will eventually (usually within 4 hours) terminate with a floating point exception error. The same behavior can be seen in Quake3. Machine is Tyan Tiger 100 motherboard with 2x PIII 700e processors installed. 128MB RAM. I have not tried other kernels to this point, and will be glad to do some troubleshooting per your guidance. Best Regards Steve McKown
What happens if you install the i586 or i386 kernel instead of the i686 kernel?
28 Jul - kernel 2.2.16-3smp compiled for 386 (updates/6.2/i386.kernel-smp-2.2.16-3.i386.rpm) has not demonstrated the problem in about 10 hours of operation where it used to happen generally within 4. It appears this compiled kernel does not exhibit the problem. All my other machines have custom-built kernels, and so it the plan for this machine. Do you have an idea of the element of the 686 kernel that is causing this issue, so that I can attempt to avoid it? I do definitely prefer to have code compiled to take advantage of the 686 instruction set if possible.
We did not enable the PIII patches (KNI instructions) in the 2.2.16-3 kernel, so that isn't the problem, at any rate. It could possibly be slightly flaky hardware that isn't stressed as hard with the other kernels, so there's no guarantee of a kernel config option that would change it. You can try building kernels with specific changes, such as turning off bigmem support -- that's one of the differences between the i686 and lower kernels.