On Fri, Oct 11, 2019 at 6:19 PM Wilco Dijkstra <wilco.dijks...@arm.com> wrote: > > Hi Ramana, > > > Can you see what happens with the Cortex-A8 or Cortex-A9 schedulers to > > spread the range across some v7-a CPUs as well ? While they aren't that > > popular today I > > would suggest you look at them because the defaults for v7-a are still to > > use the > > Cortex-A8 scheduler and the Cortex-A9 scheduler might well also get used in > > places given > > the availability of hardware. > > The results are practically identical to Cortex-A53 and A57 - there is a huge > codesize win > across the board on SPEC2006, there isn't a single benchmark that is larger > (ie. more > spilling). > > > I'd be happy to move this forward if you could show if there is no > > *increase* in spills > > for the same range of benchmarks that you are doing for the Cortex-A8 and > > Cortex-A9 > > schedulers. > > There certainly isn't. I don't think results like these could be any more > one-sided, it's a > significant win for every single benchmark, both for codesize and performance! >
Ok go ahead - please be sensitive to testsuite regressions. Ramana > What isn't clear is whether something has gone horribly wrong in the > scheduler which > could be fixed/reverted, but as it is right now I can't see it being useful > at all. This means > we should also reevaluate whether pressure scheduling now hurts AArch64 too. > > Cheers, > Wilco
