Re: [PATCH v3 00/13] Virtually mapped stacks with guard pages (x86, core)

Oleg Nesterov
2016-06-23T18:12:21Z

On 06/23, Linus Torvalds wrote:
>
> Ugh. Looking around at this, it turns out that a great example of this
> kind of legacy issue is the debug_mutex stuff.

Heh ;) I am looking at it too.

> It uses "struct thread_info *" as the owner pointer, and there is _no_
> existing reason for it. In fact, in every single place it actually
> wants the task_struct, and it does task_thread_info(task) just to
> convert it to the thread-info, and then converts it back with
> "ti->task".

Even worse, this task is always "current" afaics, so

> So the attached patch seems to be the right thing to do regardless of
> this whole discussion.

I think we should simply remove this argument.

And probably kill task_struct->blocked_on? I do not see the point of
this task->blocked_on != waiter check.

Oleg.