If stub terminates right after execution, e.g. due to lack of system
resources (requested number of cpu cores to run on, right amount of
memory, etc.) start_stub() would end up blocking forever since there
wouldn't be any entity around that would mknod spdk_stub0 for it to
break the loop.
Avoid the above scenario by checking if $stubpid is still visible
under procfs and return if it goes missing.
To make sure kill_stub() is still called to clean up after start_stub()
declare proper trap prior the call to start_stub().
Additionally, avoid potential stderr noise in case kill|wait are told
to act on a PID that's not visible in the ns anymore.
Change-Id: Ief41200c57957f84b4f96a54baabc8da1f27dd43
Signed-off-by: Michal Berger <michallinuxstuff@gmail.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/482653
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
9ba80de0dd