64bit ticks, was Re: Changing p_swtime and td_slptime to ticks

[Jeff Roberson]

On Tue, 18 Sep 2007, Garrett Wollman wrote:

> Jeff Roberson writes:
>
>> Is there a good reason for not making ticks 64bit?  math involving this
>> value is relatively infrequent.  Bruce?  Any comments?  It'd sure let us
>> forget all of these counter wrapping problems.
>
> Making ticks 64 bits on 32-bit architectures means that updates to it
> will not be atomic.

You're right.  There would be a chance that you'd get mismatched upper and 
lower halves on wrap conditions and would have to detect accordingly. 
That's probably too much trouble.

Thanks,
Jeff

>
> -GAWollman
>
> -- 
> Garrett A. Wollman   | The real tragedy of human existence is not that we are
> wollman at csail.mit.edu| nasty by nature, but that a cruel structural asymmetry
> Opinions not those   | grants to rare events of meanness such power to shape
> of MIT or CSAIL.     | our history. - S.J. Gould, Ten Thousand Acts of Kindness
>