Re: [REPORT] cfsv4 vs sd0.44
From: William Lee Irwin III
Date: Wed Apr 25 2007  02:07:39 EST
On Tue, Apr 24, 2007 at 06:22:53PM 0700, Li, Tong N wrote:
> The goal of a proportionalshare scheduling algorithm is to minimize the
> above metrics. If the lag function is bounded by a constant for any
> thread in any time interval, then the algorithm is considered to be
> fair. You may notice that the second metric is actually weaker than
> first. In fact, if an algorithm achieves a constant lag bound, it must
> also achieve a constant bound for the second metric, but the reverse is
> not necessarily true. But in some settings, people have focused on the
> second metric and still consider an algorithm to be fair as long as the
> second metric is bounded by a constant.
Using these metrics it is possible to write benchmarks quantifying
fairness as a performance metric, provided weights for nice numbers.
Not so coincidentally, this also entails a test of whether nice numbers
are working as intended.
 wli
P.S. Divide by the length of the time interval to rephrase in terms of
CPU bandwidth.

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