Ensure that we have at least 1GB per Makefile job.
Go compiler/linker can consume significant amount of memory
(observed to consume at least 600MB). See #1276 for context.
Update #1276
In some cases we start scp, which starts ssh,
then kill scp but the ssh subprocess is not killed.
As the result cmd.Wait hangs waiting for EOF on the stdout/stderr,
which are still kept alive by ssh subprocess. But ssh just hangs forever.
Create a process group for each command and kill whole process group.
Hopefully this will help.
In pkg/ipc we don't just want to UmountAll,
we want to remove all handling as many cases as possible
(mounts, read-only files, etc, similar to executor's remove_dir).
So unmounting and removing needs to be a single function,
so that it can handle all these cases.
When manager is stopped there are sometimes runaway qemu
processes still running. Set PDEATHSIG for all subprocesses.
We never need child processes outliving parents.
We currently use more complex and functional protocol on linux,
and a simple ad-hoc protocol on other OSes.
This leads to code duplication in both ipc and executor.
Linux supports coverage, shared memory communication and fork server,
which would also be useful for most other OSes.
Unify communication protocol and parametrize it by
(1) use of shmem or only pipes, (2) use of fork server.
This reduces duplication in ipc and executor and will
allow to support the useful features for other OSes easily.
Finally, this fixes akaros support as it currently uses
syz-stress running on host (linux) and executor running on akaros.
