Re: [PATCH 06/11] memcg: kmem controller infrastructure

From: David Rientjes
Date: Wed Jun 27 2012 - 15:46:13 EST


On Wed, 27 Jun 2012, Glauber Costa wrote:

> > > Nothing, but I also don't see how to prevent that.
> >
> > You can test for current->flags & PF_KTHREAD following the check for
> > in_interrupt() and return true, it's what you were trying to do with the
> > check for !current->mm.
> >
>
> am I right to believe that if not in interrupt context - already ruled out -
> and !(current->flags & PF_KTHREAD), I am guaranteed to have a mm context, and
> thus, don't need to test against it ?
>

No, because an mm may have been detached in the exit path by running
exit_mm(). We'd certainly hope that there are no slab allocations
following that point, though, but you'd still need to test current->mm.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/