Re: bio linked list corruption.

[Chris Mason]

On 10/24/2016 05:50 PM, Linus Torvalds wrote:
> On Mon, Oct 24, 2016 at 2:17 PM, Linus Torvalds
> <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> > The vmalloc/vfree code itself is a bit scary. In particular, we have a
> > rather insane model of TLB flushing. We leave the virtual area on a
> > lazy purge-list, and we delay flushing the TLB and actually freeing
> > the virtual memory for it so that we can batch things up.
>
> Never mind. If DaveJ is running with DEBUG_PAGEALLOC, then the code in
> vmap_debug_free_range() should have forced a synchronous TLB flush fro
> vmalloc ranges too, so that doesn't explain it either.

My big fear here is that we're just triggering an old stack corruption 
more reliably.  I wonder if we can make it happen much faster by 
restricting the stacks to a static list and cycling through them in lifo 
fashion?

-chris