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On Wed, May 02, 2007 at 11:18:45PM -0400, Ting Yang wrote: > I just want to point out that ->wait_runtime, in fact, stores the lag of > each task in CFS, except that it is also used by other things, and > occasionally tweaked (heuristically ?). Under normal cases the sum of > lags of all active tasks in such a system, should be a constant 0. The > lag information is equally important to EEVDF, when some tasks leave the > system (becomes inactive) carrying certain amount of lag. The key point > here is that we have to spread the lag (either negative or positive) to > all remaining task, so that the fairness of the system is preserved. I > thinks CFS implementation does not seems to handle this properly. > > I am running out time today :-( I will write an email about CFS -v8 > tomorrow, describing 2 issues in CFS I found related to this. Interesting. I haven't look at the code carefully but that wouldn't surprise me if this was the case and it led to odd corner cases. I'm eagerly waiting your analysis and explanation. bill - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ | ||||||||||||
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