Messages in this thread | | | Subject | Re: [announce] [patch] ultra-scalable O(1) SMP and UP scheduler | Date | Sat, 5 Jan 2002 23:41:38 +0000 (GMT) | From | Alan Cox <> |
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> > In fact it's the cr3 switch (movl %0, %%cr3) that accounts for about 30% > > of the context switch cost. On x86. On other architectures it's often > > much, much cheaper. > > TLB flushes are expensive everywhere, and you know exactly this and if you
Not every processor is dumb enough to have TLB flush on a context switch. If you have tags on your tlb/caches it's not a problem.
> Again, the history of our UP scheduler thought us that noone has been able > to makes it suffer with realistic/high not-stupid-benchamrks loads.
Apache under load, DB2, Postgresql, Lotus domino all show bad behaviour. (Whether apache, db2, and postgresql want fixing differently is a seperate argument)
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