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Diffstat (limited to 'tvix/eval/docs/known-optimisation-potential.md')
| -rw-r--r-- | tvix/eval/docs/known-optimisation-potential.md | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/tvix/eval/docs/known-optimisation-potential.md b/tvix/eval/docs/known-optimisation-potential.md index e7271f4b35..da9cf265ea 100644 --- a/tvix/eval/docs/known-optimisation-potential.md +++ b/tvix/eval/docs/known-optimisation-potential.md @@ -65,3 +65,19 @@ optimisations, but note the most important ones here. The same thing goes for resolving `with builtins;`, which should definitely resolve statically. + +* Avoid nested `VM::run` calls [hard] + + Currently when encountering Nix-native callables (thunks, closures) + the VM's run loop will nest and return the value of the nested call + frame one level up. This makes the Rust call stack almost mirror the + Nix call stack, which is usually undesirable. + + It is possible to detect situations where this is avoidable and + instead set up the VM in such a way that it continues and produces + the desired result in the same run loop, but this is kind of tricky + to get right - especially while other parts are still in flux. + + For details consult the commit with Gerrit change ID + `I96828ab6a628136e0bac1bf03555faa4e6b74ece`, in which the initial + attempt at doing this was reverted. |