Bug#12080: Bogus BogoMips on Cyrix 6x86 in conjuction with set6x86

Giuliano Procida (gpp10@cus.cam.ac.uk)
Thu, 14 Aug 1997 01:00:06 +0100


Package: kernel-source-2.0.30
Version: 2.0.30-8

$ grep bogo /proc/cpuinfo
bogomips : 104.65
$ bogomips
Calibrating delay loop.. ok - 119.83 BogoMips
[sometimes more, sometimes less]
$ zgrep -i bogo /var/log/messages.3.gz
[...] Calibrating delay loop.. ok - 119.60 BogoMIPS

The last figure dates from when I used a 2.0 kernel with Cyrix patches
(it never varied). My current kernel is a 2.1 one and I use set6x86
(this turns on some Cyrix funky stuff from rc.boot).

I don't know how serious the discrepancy is (> 10%) to the kernel
timings. The general point here is that the kernel has poor support
for Intel clones and it would be nice if Debian came with the best
available patches that tackle this. Ideally ones that provided kernel
config options, autodetection of chips and autoconfiguration of
features, overridable with command line options where this might be
sensible (cyrixm1=nofastloop, cyrixm1_linear=0xe000000,0x80000 ?).

I can dream, can't I?

Giuliano.

----- End of forwarded message from Giuliano Procida -----

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