Re: [patch] Re: Problem with exiting threads under NPTL

Ingo Molnar
2003-12-14T22:17:51Z

On Sun, 14 Dec 2003, Linus Torvalds wrote:

> Even though the parent ignores SIGCHLD it _can_ be running on another
> CPU in "wait4()". And since we drop the tasklist lock before we do the
> "release_task()" on the leader, and since the leader is still marked
> TASK_ZOMBIE, we may have _two_ different people trying to release it.
> First the parent, and then the last thread that still remembers the
> leader.

are you sure this can happen? eligible_child() does this:

if (p->exit_signal == -1 && !p->ptrace)
return 0;

so can the parallel situation really happen?

Ingo