Messages in this thread | | | Date | Fri, 1 Jun 2007 21:21:42 +0200 | From | Ingo Molnar <> | Subject | Re: [patch] CFS scheduler, -v14 |
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* Li Yu <raise.sail@gmail.com> wrote:
> Also, I have want to know what's real meaning of > > add_wait_runtime(rq, curr, delta_mine - delta_exec); > > in update_curr(), IMHO, it should be > > add_wait_runtime(rq, curr, delta_mine - delta_fair); > > Is this just another heuristics? or my opinion is wrong again? :-)
well, ->wait_runtime is in real time units. If a task executes delta_exec time on the CPU, we deduct "-delta_exec" 1:1. But during that time the task also got entitled to a bit more CPU time, that is +delta_mine. The calculation above expresses this. I'm not sure what sense '-delta_fair' would make - "delta_fair" is the amount of time a nice-0 task would be entitled to - but this task might not be a nice-0 task. Furthermore, even for a nice-0 task why deduct -delta_fair - it spent delta_exec on the CPU.
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