Yes we’d love help with investigating, characterising, and fixing performance bugs. Simon From: Haskell-Cafe [mailto:haskell-cafe-bounces@haskell.org] On Behalf Of Thomas Miedema Sent: 07 January 2016 00:52 To: Johannes Waldmann <johannes.waldmann@htwk-leipzig.de> Cc: Joachim Breitner <mail@joachim-breitner.de>; Haskell cafe <haskell-cafe@haskell.org> Subject: Re: [Haskell-cafe] long-range performance comparisons (GHC over the years) I recently noticed a performance problem ... What worries me is that such a regression had been sitting there for over a year There are 215 open runtime performance<https://ghc.haskell.org/trac/ghc/query?status=!closed&failure=Runtime+performance+bug&order=id> tickets (out of a total of 1655 open tickets, that makes 13%). Compared to say new typesystem features, they don't get much attention. Only a few were fixed<https://ghc.haskell.org/trac/ghc/query?failure=Runtime+performance+bug&resolution=fixed&milestone=8.0.1&milestone=7.10.3&milestone=7.10.2> this year, most of them by Joachim Breitner (the new performance tsar<https://ghc.haskell.org/trac/ghc/wiki/CodeOwners#CurrentOwners>?). He also created https://perf.haskell.org/ghc<https://na01.safelinks.protection.outlook.com/?url=https%3a%2f%2fperf.haskell.org%2fghc%2f&data=01%7c01%7csimonpj%40064d.mgd.microsoft.com%7cc3af688d2c234b3c19b608d316fcb626%7c72f988bf86f141af91ab2d7cd011db47%7c1&sdata=Ik7nCUHxNalCIxrv9E8dq2od9ed%2bbbLXJ%2fJJyHLCIhQ%3d>. In case you want to help out, start here: https://ghc.haskell.org/trac/ghc/wiki/Newcomers.