[Unison-hackers] Memory exhaustion issue (#1068)

[Greg Troxel]

Tõivo Leedjärv <toivol at gmail.com> writes:

> I tested this by patching 2.53.7 to force a GC run after the rsync
> copy path and this reduced the memory consumption on server from 28 MB
> (after syncing 6400 MB file) down to 9 MB.

It is probably a good idea to force gc when a unison server finishes
servicing a request and is going to sleep.  I don't think it's good to
poke gc all the time; there are reasons it was designed how it was.

Cleaning up before sleeping sounds good and I don't expect big
downsides.  There will be some memory references that might provoke
paging, but that's more or less taking the pain earlier.

This could be related to:

  https://urldefense.com/v3/__https://github.com/bcpierce00/unison/issues/399__;!!IBzWLUs!Qq2dqZOivi025aB7zGRuGTqoD36aKW8AVLfVOt9EzPuRa5kQxIAOCcKzSHre_1yZXmWEfSOX2KUsVfIpGHoZSLG8$