Timers and timing, was: MySQL Performance 6.0rc1
Chuck Swiger
cswiger at mac.com
Fri Oct 28 13:12:10 PDT 2005
John-Mark Gurney wrote:
> Poul-Henning Kamp wrote this message on Fri, Oct 28, 2005 at 11:56 +0200:
[ ... ]
> time(): 0.65022
> gettimeofday(): 0.60886
> hydrogen,ttypa,/tmp,503#sysctl kern.timecounter.hardware=ACPI-fast
> kern.timecounter.hardware: TSC -> ACPI-fast
[ ... ]
> time(): 1.33242
> gettimeofday(): 1.33421
>
> I was quite impressed by the speed up using the TSC over ACPI-fast...
Yes, but the frightening code in sys/i386/isa/clock.c suggests that the TSC and
SMP do not play nice together, and neither does power-management stuff.
--
-Chuck
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