Hi, this is mostly a rant, targeted at the very vague fact that runtime performance benchmarks are so damn hard. This commit just came in: https://git.haskell.org/ghc.git/commitdiff/56c9bb39246f9ffd8ed41a0656bfe8e60... Clearly, only parts of the profiling RTS have changed. This is what perf.haskell.org measures: https://perf.haskell.org/ghc/#revision/56c9bb39246f9ffd8ed41a0656bfe8e60d23b... Highlights: nofib/time/cryptarithm1  0.502  + 9.36%  0.549  seconds nofib/time/fasta  0.406  + 4.43%  0.424  seconds These changes are permanent, i.e. the following commits consistently give the higher runtimes. But nofib does not even run the profiling RTS! *very audible sigh* (Conclusion: Ignore runtime changes in nofib when the RTS has changed, the results are simply unusable.) I also wonder if we can adjust the input and parameters to nofib (in a new “veryslow” setting) to get them all run in a few seconds on modern hardware, instead of subseconds. Greetings, Joachim -- Joachim “nomeata” Breitner   mail@joachim-breitner.de • https://www.joachim-breitner.de/   XMPP: nomeata@joachim-breitner.de • OpenPGP-Key: 0xF0FBF51F   Debian Developer: nomeata@debian.org