Re: [rfc] aio-core for 2.5.29 (Re: async-io API registration for

Linus Torvalds (torvalds@transmeta.com)
Thu, 1 Aug 2002 09:30:04 -0700 (PDT)


On 1 Aug 2002, Alan Cox wrote:
>
> For a lot of applications like multimedia you actually want a counting
> of time not any relation to real time except that you can tell how many
> ticks elapse a second.

Absolutely. I think "jiffies64" is fine (as long as is it converted to
some "standard" time-measure like microseconds or nanoseconds so that
people don't have to care about internal kernel state) per se.

The only thing that I think makes it less than wonderful is really the
fact that we cannot give an accurate measure for it. We can _say_ that
what we count in microseconds, but it might turn out that instead of the
perfect 1000000 ticks a second ther would really be 983671 ticks.

A 2% error may not be a big problem for most people, of course. But it
might be a huge problem for others. Those people would have to do their
own re-calibration..

Linus

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