Re: [Announce] [patch] Modular Scheduler Core and Completely Fair Scheduler [CFS]

Nick Piggin
2007-04-17T07:33:28Z

On Tue, Apr 17, 2007 at 12:27:28AM -0700, Davide Libenzi wrote:
> On Tue, 17 Apr 2007, William Lee Irwin III wrote:
>
> > On Mon, Apr 16, 2007 at 11:50:03PM -0700, Davide Libenzi wrote:
> > > I would suggest to thoroughly test all your alternatives before deciding.
> > > Some code and design may look very good and small at the beginning, but
> > > when you start patching it to cover all the dark spots, you effectively
> > > end up with another thing (in both design and code footprint).
> > > About O(1), I never thought it was a must (besides a good marketing
> > > material), and O(log(N)) *may* be just fine (to be verified, of course).
> >
> > The trouble with thorough testing right now is that no one agrees on
> > what the tests should be and a number of the testcases are not in great
> > shape. An agreed-upon set of testcases for basic correctness should be
> > devised and the implementations of those testcases need to be
> > maintainable code and the tests set up for automated testing and
> > changing their parameters without recompiling via command-line options.
> >
> > Once there's a standard regression test suite for correctness, one
> > needs to be devised for performance, including interactive performance.
> > The primary difficulty I see along these lines is finding a way to
> > automate tests of graphics and input device response performance. Others,
> > like how deterministically priorities are respected over progressively
> > smaller time intervals and noninteractive workload performance are
> > nowhere near as difficult to arrange and in many cases already exist.
> > Just reuse SDET, AIM7/AIM9, OAST, contest, interbench, et al.
>
> What I meant was, that the rules (requirements and associated test cases)
> for this new Scheduler Amazing Race should be set forward, and not kept a
> moving target to fit&follow one or the other implementation.

Exactly. Well I don't mind if it is a moving target as such, just as
long as the decisions are rational (no "blah is more important
because I say so").