[tracking-only] Performance improvements in the operating systems to possibly be considered

Last update: 2018-03-26

This is not immediately actionable, and is not an "issue" per se.
But good to start tracking the performance related goodies as they are coming
to the operating systems (but long standing ones also count), so they can
speculatively be taken into account. Also, not everything is necessarily relevant,
though some superficial care is taken, and it is to be digested lazily, should this
or other topic become relevant, because of bugfixing, implementing a new feature,
and whatnot.

If you have anything to add, please post a comment and I'll reflect that in this
initial comment. When there's more content, we can move it over to a separate
wiki page there.

## Linux

[Primary source](http://blog.stgolabs.net/search/label/performance)

### 4.15

* epoll: scale nested calls
- [57a173bdf5ba](https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=57a173bdf5baab48e8e78825c7366c634acd087c)
- [37b5e5212a44](https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=37b5e5212a448bac0fe29d2a51f088014fbaaa41)

* ipc: scale INFO commands
- [15df03c87983](https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=15df03c87983660a4d1eedb4541778592bd97684)

### 4.14

* sysvipc: scale key management
- [0cfb6aee70bd](https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0cfb6aee70bddbef6ec796b255f588ce0e126766)