Messages in this thread | | | Date | Thu, 25 Apr 2024 13:51:25 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH] sched/fair.c: Fix the calculation method of 'lag' |
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On Thu, Apr 25, 2024 at 07:44:59PM +0800, hupu@oppo.com wrote: > > > From: hupu <hupu@oppo.com> > > > > > > I think the 'lag' calculation here is inaccurate. > > > > > > Assume that delta needs to be subtracted from v_i to ensure that the > > > vlag of task i after placement is the same as before. > > > > Why ?!? v_i is the unkown, it makes no sense to complicate things by > > adding extra unknowns. > > > > > At this time, the > > > vlag of task i after placement should be: > > > vl'_i = V' - (v_i - delta) > > > > But but but, you can't have V' without knowing v_i. > > > > Thank you for your patient guidance. I overlooked a important fact that > v_i is unknown in the process of proof. Below is the complete proof > process, and it turns out that you are correct.
*phew*, thanks for checking!
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