[Well-Typed Blog] Reducing Haddock's Memory Usage

Haddock is the documentation generation tool for Haskell.

Recently, Mercury asked us to investigate performance problems in Haddock that were preventing their developers from using it effectively.

At a high level, the work covered by this post has resulted in Haddock’s memory usage being roughly halved. The full set of Haddock and GHC changes resulting in these improvements will be shipped with GHC 9.8.

All this profiling and debugging work was completed using the eventlog2html and ghc-debug tools.