Messages in this thread |  | | | Date | Tue, 18 Dec 2001 09:22:37 -0800 (PST) | | From | Linus Torvalds <> | | Subject | Re: Scheduler ( was: Just a second ) ... |
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On Tue, 18 Dec 2001, Mike Kravetz wrote: > On Tue, Dec 18, 2001 at 02:09:16PM +0000, Alan Cox wrote: > > The scheduler is eating 40-60% of the machine on real world 8 cpu workloads. > > That isn't going to go away by sticking heads in sand. > > Can you be more specific as to the workload you are referring to? > As someone who has been playing with the scheduler for a while, > I am interested in all such workloads.
Well, careful: depending on what "%" means, a 8-cpu machine has either "100% max" or "800% max".
So are we talking about "we spend 40-60% of all CPU cycles in the scheduler" or are we talking about "we spend 40-60% of the CPU power of _one_ CPU out of 8 in the scheduler".
Yes, 40-60% sounds like a lot ("Wow! About half the time is spent in the scheduler"), but I bet it's 40-60% of _one_ CPU, which really translates to "The worst scheduler case I've ever seen under a real load spent 5-8% of the machine CPU resources on scheduling".
And let's face it, 5-8% is bad, but we're not talking "half the CPU power" here.
Linus
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