On Wednesday, August 06, 2014 02:19:17 PM Mel Gorman wrote: > The menu_select function is heavy and is very noticable in profiles for > workloads that enter/leave idle state a lot. This primarily happens > for scheduler microbenchmarks. The biggest contibution is the standard > deviation calculations and comparisons but the excessive calls into > the scheduler core do not help. > > It would be nice to reduce the number of times nr_iowait is checked to > once per 8 intervals but I was not sure how to measure what the general > impact of such a change could be. > > Similiarly I looked at different ways the standard deviation could be > calculated but the standard equivalent calculations potentially overflow. > It could be done as rolling average and rolling deviation but again > it was unclear how that could be evaluated. Tips on how the goodness/badness > of governor changes are evalated would be nice. > > In the meantime, here are patches against some of the obvious stuff.
They look good, I'm going to apply them. Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
