Summary:
If torch.multiprocessing.spawn is used to launch non-daemonic
processes (the default since #14391), the spawned children won't be
automatically terminated when the parent terminates.
On Linux, we can address this by setting PR_SET_PDEATHSIG, which
delivers a configurable signal to child processes when their parent
terminates.
Fixes#14394.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/14491
Differential Revision: D13270374
Pulled By: pietern
fbshipit-source-id: 092c9d3c3cea2622c3766b467957bc27a1bd500c