Re: init's children list is long and slows reaping children.

[ebiederm@xmission.com (Eric W. Biederman)]

Oleg Nesterov <oleg@tv-sign.ru> writes:

> No! That is why I suggest (a long ago, in fact) to move ->children into
> ->signal_struct. When sub-thread forks, we set ->parent = group_leader.
> We don't need forget_original_parent() until the last thead exists. This
> also simplify do_wait().
>
> However, this breaks the current ->pdeath_signal behaviour. In fact (and
> Eric thinks the same) this _fixes_ this behaviour, but may break things.

Thinking about this.  As contingency planning if there is something in user
space that actually somehow cares about pdeath_signal, from a threaded
parent we can add a pdeath_signal list, to the task_struct and get
rid of the rest of the complexity.

I think I want to wait until someone screams first.

This does very much mean that we can remove the complexity of
a per thread ->children without fear, of having to revert everything.

Eric