Re: alloc_area_pte: page already exists

[Bjorn Wesen]

On Thu, 9 Aug 2001, Andrea Arcangeli wrote:
> > IOW I want the irq to "trigger" the freeing of the iovecs but it's ok if
> > it's done later, as long as it's done without any races :)
> 
> Your design looks suspect, but you can do that safely (at least as far
> as vfree is concerned) with keventd's schedule_task().

Ok will try

The design is shit but needed in this application... 

> > BTW how does vfree cope with not walking all tasks pgd's to remove the
> > relevant pte's ? Doesn't that give exactly this kind of problem ? (pte's
> 
> vfree as usual walks the pgd/pmd to reach the pte. It knows the
> pgd/pmd/pte cannot go away and it serlializes against vmalloc with the
> vmlist_lock, it sounds ok.

So what happens when the kernel accesses the non-existant pte's or when
the vmalloc space runs out ?

/Bjorn