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

Oleg Nesterov
2016-06-24T20:22:17Z

On 06/24, Michal Hocko wrote:
>
> On Fri 24-06-16 16:05:58, Michal Hocko wrote:
> > On Thu 23-06-16 20:52:21, Oleg Nesterov wrote:
> > >
> > > But I agree, this is fixable (and in fact I still hope TIF_MEMDIE will die,
> > > at least in its current form).
> >
> > We can move the flag to the task_struct.

Well, I actually meant that to me its usage doesn't look really
right and we need to change this logic. But this is off-topic.

> Here is the patch.

Can't comment, but note that it was decided to move ti->flags into
task_struct, so the patch is "off-topic" too ;)

> @@ -1856,6 +1856,8 @@ struct task_struct {
> unsigned long task_state_change;
> #endif
> int pagefault_disabled;
> + /* oom victim - give it access to memory reserves */
> + atomic_t memdie;

Yet another oom member. And these atomic_add_unless's look a bit
strange, it seems that you could add "bool memdie" and use xchg()
with the same effect?

Oleg.