Messages in this thread | | | Date | Wed, 09 Sep 2009 02:38:37 +0300 | From | Nikos Chantziaras <> | Subject | Re: BFS vs. mainline scheduler benchmarks and measurements |
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On 09/09/2009 02:20 AM, Jiri Kosina wrote: > On Wed, 9 Sep 2009, Nikos Chantziaras wrote: > >>>> Here the result: >>>> >>>> http://foss.math.aegean.gr/~realnc/pics/latop2.png >>>> >>>> Again: this is on an Intel Core 2 Duo CPU. >>> >>> Just an idea: Maybe some system management code hits you? >> >> I'm not sure what is meant with "system management code." > > System management interrupt happens when firmware/BIOS/HW-debugger is > executed in privilege mode so high, that even OS can't do anything about > that. > > It is used in many situations, such as > > - memory errors > - ACPI (mostly fan control) > - TPM > > OS has small to none possibility to influence SMI/SMM. But if this would > be the cause, you should probably obtain completely different results on > different hardware configuration (as it is likely to have completely > different SMM behavior).
Wouldn't that mean that a BFS-patched kernel would suffer from this too?
In any case, of the above, only fan control is active, and I've run with it disabled on occasion (hot summer days, I wanted to just keep it max with no fan control) with no change. As far as I can tell, the Asus P5E doesn't have a TPM (the "Deluxe" and "VM" models seem to have one.) As for memory errors, I use unbuffered non-ECC RAM which passes a memtest86+ cycle cleanly (well, at least the last time I ran it through one, a few months ago.)
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