On Wed, 25 Jul 2007, Tom Lane wrote:
Gentoo always leaves me wondering exactly what I'm running today, and I think reproducibility is an important attribute for a benchmarking machine.
At this point, there's enough performance variations even between individual Linux kernel releases that I'm not sure how much reproducibility you're ever going to get here. Are the differences between Gentoo and RHEL any bigger than those, say, between RHEL and SuSE?
The idea of setting this up with a long-term stable distribution runs counter to one of the things that I think is important to explore here, which is testing how more recent Linux kernels have improved their scalability. Do you really want to put a lot of time into identifying and working around the source of a problem with the typically older kernels that ship with the more stable releases if one answer is "that goes away if you use 2.6.21 or later because they fixed the bug that caused it"? I've watched that sort of thing happen with PG+Linux, and when involved in one of the recent roving talks Gavin mentioned I recall him mentioning a bit of that experience himself. You'd be hard pressed to find a better platform for that kind of experimentation than Gentoo.
The best you can hope for, I think, is that you can walk away with some general benchmark expectations and "on Gavin's machine, this worked better"; then try to replicate that improvement elsewhere. If you want to push bleeding edge performance, I'd expect it's impractical to do that and target long-term results stability at the same time.
-- * Greg Smith [EMAIL PROTECTED] http://www.gregsmith.com Baltimore, MD ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
