Re: Possible spin-problem in nanosleep()

[Richard B. Johnson]

On Thu, 23 Jun 2005, Alan Cox wrote:

> For most platforms the scheduler measured busy/idle time is from the
> timer tick. That means its sampled so you are limited to accurate
> information on sleep/wake changes occuring at 1/2 the clock rate or
> less.
>
> Alan

So, with a 100 ms sleep, I should see 100 +/- 1 ms, possibly 2 ms
difference in sleep between processes. Then they might not get the
CPU for a whole quantum? Wouldn't each task get the CPU for a whole
tick?

Are you saying that each might get the CPU from between 0 and 1
tick, i.e., asynchronous with the tick? If so, depending upon the
phase between the timer-tick and when a task gets awakened, a task
may never get any CPU time at all. If so, this is a bug.


Cheers,
Dick Johnson
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