Con Kolivas wrote:Actually the lower HZ has something to do with that, and tuning swappiness can also help a lot.
On Monday 03 April 2006 21:59, Al Boldi wrote:
Con Kolivas wrote:You're assuming there is some meaningful relationship between changes in
None of the current "tunables" have easily understandable heuristics.Couldn't this be fixed with an autotuning module based on cpu/mem/ctxt
Even those that appear to be obvious, like timselice, are not. While
exporting tunables is not a bad idea, exporting tunables that noone
understands is not really helpful.
performance?
cpu/mem/ctxt performance and these tunables, which isn't the case.
Furthermore if this was the case, noone understands it, can predict it or
know how to tune it. Just saying "autotune it" doesn't really tell us how
exactly the change those tunables in relation to the other variables.
Since Mike and I understand them reasonably well I think we'd both agree
that there is no meaningful association.
After playing w/ these tunables it occurred to me that they are really only deadline limits, w/ a direct relation to cpu/mem/ctxt perf.
i.e timeslice=1 on i386sx means something other than timeslice=1 on amd64
It follows that w/o autotuning, the static default values have to be selected to allow for a large underlying perf range w/ a preference for the high range. This is also the reason why 2.6 feels really crummy on low perf ranges.
Autotuning the default values would allow to tighten this range specific to the hw used, thus allowing for a smoother desktop experience.--