Re: Possible Pentium MMX CPU bug?

Adam D. Bradley (
Fri, 28 Nov 1997 18:21:15 -0500 (EST)

> Affected CPUs: only two CPUs were tested so far, a Stepping 7 P54C, and a
> Stepping 3 MMX Pentium.

Data point: Pentium (classic) 166, kernel compiled -D586, never had
"the Quake problem"...

peter> cat /proc/cpuinfo
processor : 0
cpu : 586
model : Pentium 75+
vendor_id : GenuineIntel
stepping : 12
fdiv_bug : no
hlt_bug : no
f00f_bug : yes
fpu : yes
fpu_exception : yes
cpuid : yes
wp : yes
flags : fpu vme de pse tsc msr mce cx8 apic
bogomips : 66.76
peter> uname -a
Linux peter 2.0.32 #2 Thu Nov 20 17:36:59 EST 1997 i586
peter> ./bug
testing bug ... no Pentium MMX 'missed write' bug in this CPU.

> -- mingo

Curious: should your test program always catch the bug, or might it be
a good idea for people who have seen the Quake problem before to maybe
run the test 1000 times or so if it initially reports "no bug"?


Things look so bad everywhere      Adam D. Bradley
In this whole world what is fair        Boston University Computer Science
We walk blind and we try to see             Ph.D. student and Linux hacker
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