* Mel Gorman <mgorman@xxxxxxx> wrote: > > [...] > > > > stddev appears to be rather large especially around a client count > > of 7-8. It will be difficult to fine-tune the TLB range flush > > constants if noise is too large. > > The number of iterations were very low to have high confidence of > the figures. The high standard deviation for 5 clients was a single > large outlier. It potentially could be stabilised to some extent by > bumping up the number of iterations a lot and using percentiles > instead of means. Fair enough - and you were bisecting so length of runtime and confidence of detection were obviously the primary concerns. > I'm a bit wary of optimising the TLB flush ranges based on the > benchmark even if we stabilised the figures. [...] Absolutely - but they do appear to be pretty 'adversarial' to the TLB optimization, with a measurable slowdown in a pretty complex, real-life workload pattern. So future tuning efforts will have to take such workloads into effect as well, to make sure we don't regress again. Thanks, Ingo -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>