Re: [Fwd: [-mm] Add an owner to the mm_struct (v9)]

[Oleg Nesterov <oleg@tv-sign.ru>]

On 04/15, Paul Menage wrote:
>
> On Tue, Apr 15, 2008 at 10:13 AM, Oleg Nesterov <oleg@tv-sign.ru> wrote:
> >
> >  Let's suppose the process with a lot of threads does exit_group() and nobody
> >  else uses this ->mm. How many time we will re-assign mm->owner and iterate
> >  over the all threads in system ?
> >
> 
> In general we won't get to the third loop, since one of the first two
> loops (children or siblings) will find another mm user.

Well yes, the second loop checks parent->children ... all sub-threads have
the same parent.

I'd suggest to use ->real_parent though. And the third loop could be

	for_each_process(g) {
		c = g;
		do {
			if (!c->mm)
				continue;
			if (c->mm != mm)
				break;
			goto assign_new_owner;
		} while_each_thread(g, c);
	}

Still. can't we make mm->mm_users_list ?

Oleg.