Re: [RFT] Please test rdtsc on various x86-64 hardware (app included)

From: Andi Kleen
Date: Mon Apr 18 2011 - 18:11:00 EST


I tested it on a dual Westmere-EP and a Quad Westmere-EX.
Seems to pass everywhere.

However I kept the default MAX_THREADS 4. Shouldn't that be
increased for the large systems?

I suspect the tests as written didn't really use the large
systems.

Dual:

CPU vendor : GenuineIntel
CPU model : Intel(R) Xeon(R) CPU E5640 ...
CPU stepping : ..
TSC flags : tsc rdtscp constant_tsc nonstop_tsc
Using lfence_rdtsc because you have an Intel CPU
Will test the "lfence;rdtsc" clock.
Now test failed : worst error 48 with 48647928 samples
Load3 test passed: margin 368 with 1013805 samples
Load test passed : margin 368 with 4142659 samples
Store test failed as expected: worst error 2940 with 4298473 samples

Quad:

CPU vendor : GenuineIntel
CPU model : Intel(R) Xeon(R) CPU E7 ...
CPU stepping : ..
TSC flags : tsc rdtscp constant_tsc nonstop_tsc
Using lfence_rdtsc because you have an Intel CPU
Will test the "lfence;rdtsc" clock.
Now test passed : margin 208 with 11997136 samples
Load3 test passed: margin 812 with 98710 samples
Load test passed : margin 208 with 1259451 samples
Store test failed as expected: worst error 9284 with 1086616 samples


-Andi
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