Messages in this thread | | | Date | Tue, 28 Aug 2007 09:34:03 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: CFS review |
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On Tue, 28 Aug 2007, Al Boldi wrote: > > I like your analysis, but how do you explain that these stalls vanish when > __update_curr is disabled?
It's entirely possible that what happens is that the X scheduling is just a slightly unstable system - which effectively would turn a small scheduling difference into a *huge* visible difference.
And the "small scheduling difference" might be as simple as "if the process slept for a while, we give it a bit more CPU time". And then you get into some unbalanced setup where the X scheduler makes it sleep even more, because it fills its buffers.
Or something. I can easily see two schedulers that are trying to *individually* be "fair", fighting it out in a way where the end result is not very good.
I do suspect it's probably a very interesting load, so I hope Ingo looks more at it, but I also suspect it's more than just the kernel scheduler.
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