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On Sep 1, 2004, at 9:46 PM, Frederick Bruckman wrote:

> On Wed, 1 Sep 2004, Jason Thorpe wrote:
>
>> On Sep 1, 2004, at 7:41 PM, Frederick Bruckman wrote:
>>
>>> Now, hzto() takes great care to round up, but the nano-second is lost
>>> before getting there in TIMESPEC_TO_TIMEVAL(). Should TS...TV always
>>> round up? It seems, with the present state of affairs, that any 
>>> number
>>> of timers in the kernel could be firing slightly too early. There's 
>>> no
>>> harm, ever, in a timer firing nanoseconds late (or later), is there?
>>
>> Maybe if you're controlling spark plugs (well, ok, so you're not 
>> going to pop a hole in your piston if the timing is slightly 
>> retarded)... but, in any case, we're not, so no, I don't think 
>> there's any harm in it.
>
> Well, I'm running X and listening to streaming audio with this...

I guess I should clarify... there may be times when you want "truncate" 
and times when you want "round".  Perhaps we need a TS_TO_TV macro for 
each.

>
>
> Index: sys/sys/time.h
> ===================================================================
> RCS file: /cvsroot/src/sys/sys/time.h,v
> retrieving revision 1.41
> diff -u -r1.41 time.h
> --- sys/sys/time.h	6 Sep 2003 22:01:21 -0000	1.41
> +++ sys/sys/time.h	2 Sep 2004 03:03:28 -0000
> @@ -65,7 +65,11 @@
>  }
>  #define	TIMESPEC_TO_TIMEVAL(tv, ts) {					\
>  	(tv)->tv_sec = (ts)->tv_sec;					\
> -	(tv)->tv_usec = (ts)->tv_nsec / 1000;				\
> +	(tv)->tv_usec = ((ts)->tv_nsec + 999) / 1000;			\
> +	if ((tv)->tv_usec >= 1000000) {					\
> +		(tv)->tv_sec += 1;					\
> +		(tv)->tv_usec -= 1000000;				\
> +	}								\
>  }
>
>  /*
>
>
> and no flames are flying out of the carburator. What's surprising to 
> me, is that the kernel is exactly the same size with and without, when 
> compiled with --march=pentium4.
>
>
> Frederick
>
         -- Jason R. Thorpe <thorpej@wasabisystems.com>


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