On Mon, Apr 16, 2007 at 11:09:55PM -0700, William Lee Irwin III wrote: > On Tue, Apr 17, 2007 at 02:17:22PM +1000, Peter Williams wrote: > >> I myself was thinking of this as the chance for a much needed > >> simplification of the scheduling code and if this can be done with the > >> result being "reasonable" it then gives us the basis on which to propose > >> improvements based on the ideas of others such as you mention. > >> As the size of the cpusched indicates, trying to evaluate alternative > >> proposals based on the current O(1) scheduler is fraught. Hopefully, > > On Tue, Apr 17, 2007 at 06:29:54AM +0200, Nick Piggin wrote: > > I don't know why. The problem is that you can't really evaluate good > > proposals by looking at the code (you can say that one is bad, ie. the > > current one, which has a huge amount of temporal complexity and is > > explicitly unfair), but it is pretty hard to say one behaves well. > > And my scheduler for example cuts down the amount of policy code and > > code size significantly. I haven't looked at Con's ones for a while, > > but I believe they are also much more straightforward than mainline... > > For example, let's say all else is equal between them, then why would > > we go with the O(logN) implementation rather than the O(1)? > > All things are not equal; they all have different properties. I like
Exactly. So we have to explore those properties and evaluate performance (in all meanings of the word). That's only logical. > On a random note, limitations on kernel address space make O(lg(n)) > effectively O(1), albeit with large upper bounds on the worst case > and an expected case much faster than the worst case. Yeah. O(n!) is also O(1) if you can put an upper bound on n ;) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
