--- On Mon, 6/7/10, Don Stewart <[email protected]> wrote:
> From: Don Stewart <[email protected]> > Subject: Re: [Haskell-cafe] Problems with threading? > To: "Louis Wasserman" <[email protected]> > Cc: "Haskell Café List" <[email protected]> > Date: Monday, June 7, 2010, 2:50 PM > wasserman.louis: > > While working on the Shootout, I noticed the following > benchmarks: > > > > http://shootout.alioth.debian.org/u64/program.php?test=chameneosredux〈=ghc&; > > id=3 > > http://shootout.alioth.debian.org/u64q/program.php?test=chameneosredux〈= > > ghc&id=3 > > > > The same program becomes almost 4 times slower when > compiled with --threaded > > and run with +RTS -N5 -- even though the multi-core > benchmark really only ever > > uses one processor. > > Using -N5 sounds suspicious. There are only 4 cores on the > machine. -N5 is likely to have been your orsuggestion for getting the most out of ghc 6.10.* :-) -snip- > > I wanted to throw this out for people to discuss, > > because I'd like to see it improved. As Louis has already mentioned this to me, I'll take the opportunity to sketch out a simple approach - 1) GHC programs compiled without -threaded and run without +RTS -N are already shown for x86 and x64 http://shootout.alioth.debian.org/u32/compare.php?lang=ghc http://shootout.alioth.debian.org/u64/compare.php?lang=ghc 2) For quad-core, the GHC programs will all be compiled with -threaded and all run with +RTS -N4 3) That seems to match the approach taken with Erlang, where all the programs on quad-core run with smp built into the vm, and all the programs on one core run without smp built into the vm. _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
