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SubjectRe: Machines misreporting Bogomips
On 31 Jan 2002 at 17:55, Greg Boyce wrote:

> kernel folk,
>
> I've got a strange issue that I've been struggling to find the solution to
> for some time now.
>
> I work in a group that assists in the managing of large numbers of
> deployed linux boxes running variants of the 2.2 kernel on them. The
> machines themselves are all pretty standard. There are slight variances
> on vendors, cpu speeds, etc., but they're all running from the same
> motherboards.
>
> Every once in a while we come across single machines which are running a
> lot slower than they should be, and are misreporting their speed in
> bogomips under /proc/cpuinfo. Reinstalling the OS and changing versions
> of the kernel don't appear to affect the machines themselves at all.
>
> I was wondering if anyone would be able to provide me with a starting
> point to hunt this down. The only solution we had found in the past was
> to replace the machines, but some of them are located out of the country
> and that would be expensive.

It seems to me that there was an issue with timers not being set up
properly, or changing their settings during startup, which could cause a
machine to behave like it was running slow. On more recent 2.2.x kernels
you would see a line like 'timer configuration lost' in dmesg, which meant
that the computer had the problem, and a workaround was being implimented.

On kernels that didn't detect the timer problem you could sometimes boot
with no problem, but other times you'd get a kernel that seemed to run very
slowly.

I don't remember if it affected the bogomips reporting, but I would think
that it could.

BTW, I think that the kernels I had the problems with were pre 2.2.17,
though I'm not positive. 2.2.20 and 2.2.19 do not exhibit the problem. i.e.
they detect the problem and work around it.




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