Backport haskell backpack and profiling fixes #46163
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(cherry picked from commit a7d8800)
`all-functions` corresponds to `-fprof-auto` which places an SCC on every binding. It is well known that SCCs hinder GHC from doing its optimization magic and really slows down profiled code to a point where the profiling reports are completely skewed towards things that were completely optimized away in production settings. Concretely this shows up with things like lenses which do not carry runtime overhead when properly simplified. `exported-functions` corresponds to GHCs `-fprof-auto-exported` which doesn't put SCCs on `INLINE`d code and in turn doesn't influence simplification of this basic but important stuff. (cherry picked from commit 3c70c4c)
See https://phabricator.haskell.org/D5123. (cherry picked from commit cbf1943)
See https://phabricator.haskell.org/D5123. (cherry picked from commit 06a3db6)
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No attempt on aarch64-linux (full log) The following builds were skipped because they don't evaluate on aarch64-linux: ghc, haskell.compiler.ghc861 Partial log (click to expand)
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Timed out, unknown build status on x86_64-linux (full log) Attempted: ghc, haskell.compiler.ghc861 Partial log (click to expand)
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Timed out, unknown build status on x86_64-darwin (full log) Attempted: ghc, haskell.compiler.ghc861 Partial log (click to expand)
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I'm not familiar with mass rebuilds (if this is one), and the usual timings and such. Any tip? |
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This is a mass-haskell rebuild. I created the relevant hydra jobset already and the cache is mostly populated. There's been some discussion around this lately so it might have changed, but in the past we've just merged major rebuilds into staging (or, for haskell, haskell-updates), then when the relevant jobset stabilized and binaries uploaded anyone could just merge it into master or the relevant release branch. Since we're still in release prep mode I didn't want to just merge in churn unwarned, though. |
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Ah, yes, timing seems good. I've been falling behind notification updates. There's this tarball problem blocking channels on both master and 18.09 anyway... |
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Jobset at https://hydra.nixos.org/jobset/nixpkgs/haskell-updates-18.09