On Fri, 2008-10-24 at 11:47 -0600, Chris Friesen wrote:Peter Zijlstra wrote:
> Then renicing, esp when lowering nice value (getting heavier), its possible
> to get into a starvation scenario. If you got too much runtime as a very
> light task, you get shot way far too the right, which means you'll have to
> wait for a long time in order to run again.
>
> If during that wait you get reniced down, fairness would suggest you get run
> earlier, because you deserve more time.
>
> This can be solved by scaling the vruntime so that we keep the real-time
> lag invariant.
If we've already been shot way out to the right, presumably that would give us a large real-time lag. If we renice to a lower nice level, wouldn't we want to reduce the real-time lag rather than make it constant?