Wall clock accuracy
Eugene Surovegin
ebs at ebshome.net
Wed Aug 10 03:20:53 EST 2005
On Tue, Aug 09, 2005 at 12:04:10PM -0500, Rune Torgersen wrote:
>
> My bigger problem with the walltime is that time_nsec should have been
> 1000000, not 999848 to begin with. If it had been, I would probably
> never even have noticed it.
>
> The thing is that that value is set based on a value I cannot find any
> reference as how was chosen. Looks to be a leftover when porting PPC
> fron i386 once upon a time.
>
> time_nsec basically gets is value (via some macros) from
> CLOCK_TICK_RATE, which is defined in asm-ppc/timex.h to be 1193180
>
> In my opinion, time_nsec should have been calculated based on the actual
> clock input rate to begin with (like in calibrate_decrementer()).
Fair enough, why then instead of fixing the root cause you are making
ugly workarounds :) ?
--
Eugene
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