There was a paper at the Haskell Symposium 2009, and the video is online: http://www.vimeo.com/6680185
Thanks, Neil On Tue, Jan 5, 2010 at 2:23 AM, Jamie Morgenstern <cantthinkthinkp...@gmail.com> wrote: > I am using 6.12... are there any good pointers as to how one uses > threadscope? > > On Mon, Jan 4, 2010 at 3:14 PM, Neil Mitchell <ndmitch...@gmail.com> wrote: >> >> Hi Jamie, >> >> First question, what version of GHC are you using? There are >> significant performance improvements to parallel code in GHC 6.12, so >> it's worth an upgrade. Once you've upgraded you might want to try out >> threadscope which is designed to help track down these sorts of >> problems. >> >> If you are using 6.10, I recommend turning off parallel garbage >> collection with the RTS flags (see the manual) as that can cause >> slowdowns. >> >> Thanks, Neil >> >> 2010/1/4 Jamie Morgenstern <cantthinkthinkp...@gmail.com>: >> > Hello; >> > >> > I have a piece of code in which I employ the `par` construct to add >> > some implicit parallelism >> > to a theorem prover. However, when running the *same* code with >> > >> > +RTS -N1 >> > +RTS -N5 >> > +RTS -N10 >> > >> > I see a huge slowdown (a factor of 50 with 5 processes and a factor of >> > 100 for 10 on an 8-core machine). >> > >> > Very little time is being spent using the garbage collector. Any >> > suggestions? >> > >> > Thanks, >> > -Jamie >> > >> > _______________________________________________ >> > Haskell-Cafe mailing list >> > Haskell-Cafe@haskell.org >> > http://www.haskell.org/mailman/listinfo/haskell-cafe >> > >> > > > _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe