On Thu, 21 May 2015 12:30:21 +0200 Alban Crequy <alban.crequy@xxxxxxxxx> wrote: > commit 818411616baf ("fs, proc: introduce > /proc/<pid>/task/<tid>/children entry") introduced the children entry > for checkpoint restore and the file is only available on kernels > configured with CONFIG_EXPERT and CONFIG_CHECKPOINT_RESTORE. > > This is available in most distributions (Fedora, Debian, Ubuntu, CoreOS) > because they usually enable CONFIG_EXPERT and CONFIG_CHECKPOINT_RESTORE. > But Arch does not enable CONFIG_EXPERT or CONFIG_CHECKPOINT_RESTORE. > > However, the children proc file is useful outside of checkpoint restore. > I would like to use it in rkt. The rkt process exec() another program it > does not control, and that other program will fork()+exec() a child > process. I would like to find the pid of the child process from an > external tool without iterating in /proc over all processes to find > which one has a parent pid equal to rkt. > > Since the children proc file is useful outside of checkpoint-restore, > I am removing the guard on CONFIG_CHECKPOINT_RESTORE. This will add a lump of code to kernels which don't need it. It's a bit of a pain, but I suppose we should still keep the presence of get_children_pid() configurable. That would be by adding a new CONFIG_PROC_CHILDREN (or similar) and making CONFIG_CHECKPOINT_RESTORE select that. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html