Messages in this thread | | | From | "Davide Libenzi" <> | Subject | Re: Auto-Adaptive scheduler - Final chapter ( the numbers ) ... | Date | Thu, 27 Jan 2000 18:18:06 +0100 |
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Thursday, January 27, 2000 6:10 PM Horst von Brand <vonbrand@pincoya.inf.utfsm.cl> wrote : > As was said here time and again: This is ridiculously unrealistic. Your > benchmark plus whatever scheduler you use fits in the smallest cache. Use > some code that is some 2 or 3Kb at least between schedules, and run > _different_ code each time. I'd bet you see quite different numbers that way.
These are my words in Larry answer :
<DONTSPLITTHIS> This is a pure switching time test. It is a _real_ switching test, that can be used to test switching times under _certain_ RQ loads :
vmstat of a "lat_ctx -s 0 20" give no more than 5-6 tasks in RQ
vmstat of a "threads 20 xx" give always an RQ = 20 ( with no need of cost compensation )
Now, as even my sister ( that works in business ) can realize this code is stored entirely in cache, and the write to the counter is onto the process stack. I _want_ this behaviour coz I _want_ a measure of clean switching times by keeping cache issues ot of the test. </DONTSPLITTHIS>
Anyway adding a cache footprint into the two cases will add a constant term that minimize even more the percent result.
Davide.
-- All this stuff is IMVHO
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