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List:       linux-kernel
Subject:    Re: Machines misreporting Bogomips
From:       Roger Larsson <roger.larsson () norran ! net>
Date:       2002-01-31 23:30:48
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On Fridayen den 1 February 2002 00.21, Matthew Dharm wrote:
> I don't know if this will help much, but I have seen that type of
> performance drop on systems when the entire cache is disabled.
>
> Matt

From the report below...
> > cache size	: 0 KB

/RogerL

>
> On Thu, Jan 31, 2002 at 05:55:57PM -0500, 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.
> >
> > Here is the output from /proc/cpuinfo for machines.  The first machine is
> > normal, the second is affected by this bug.  They're both running the
> > same hardware, although the first machine's CPU is 650mhz instead of
> > 500mhz.
> >
> > Machine 1:
> > processor	: 0
> > vendor_id	: GenuineIntel
> > cpu family	: 6
> > model		: 8
> > model name	: Pentium III (Coppermine)
> > stepping	: 3
> > cpu MHz		: 645.676332
> > cache size	: 0 KB
> > fdiv_bug	: no
> > hlt_bug		: no
> > sep_bug		: no
> > f00f_bug	: no
> > coma_bug	: no
> > fpu		: yes
> > fpu_exception	: yes
> > cpuid level	: 3
> > wp		: yes
> > flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca
> > cmov pat pse36 psn mmx osfxsr kni
> > bogomips	: 643.89
> >
> > Machine 2:
> > processor	: 0
> > vendor_id	: GenuineIntel
> > cpu family	: 6
> > model		: 7
> > model name	: Pentium III (Katmai)
> > stepping	: 3
> > cpu MHz		: 496.677416
> > cache size	: 512 KB
> > fdiv_bug	: no
> > hlt_bug		: no
> > sep_bug		: no
> > f00f_bug	: no
> > coma_bug	: no
> > fpu		: yes
> > fpu_exception	: yes
> > cpuid level	: 2
> > wp		: yes
> > flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca
> > cmov pat pse36 mmx osfxsr kni
> > bogomips	: 4.06
> >
> > Let me know if there's anything else I can provide to help with the
> > diagnosis.  The machine itself is an IBM Netfinity 4000R.
> >
> > --
> > Gregory Boyce
> >
> >
> > -
> > To unsubscribe from this list: send the line "unsubscribe linux-kernel"
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-- 
Roger Larsson
Skellefteċ
Sweden
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