Post #1546568

@cliffle @regehr I do partially agree with that! However, the _effect_ of allocation failure is (in principle) easier to recover from when memory overcommit is disabled, and I think that tips the scale in favor of no overcommit, at least as a default. It _should_ also be paired with things like actually effective rlimits for memory usage, the ability to say "no _single process_ can occupy more than X% of physical RAM", etc.