Splitting task-group stuff from task_struct

Hi Linus, Andrew,

Would you have any objection to task-group specific stuff being split from the task_struct and placed into a refcounted structure of its own and shared upon CLONE_THREAD.

The fields I'm thinking of include:

struct linux_binfmt *binfmt
unsigned long personality
pid_t tgid
struct task_struct *group_leader
u32 parent_exec_id;
u32 self_exec_id;

Should process credentials be shared?

I could then add the process/session keyring pointers from my patch to it too.

David