Re: [RFC][PATCH] kmap_atomic_push

Ingo Molnar
2009-10-08T15:53:44Z

* Peter Zijlstra <peterz@infradead.org> wrote:

> The below patchlet changes the kmap_atomic interface to a stack based
> one that doesn't require the KM_types anymore.
>
> This significantly simplifies some code (more still than are present
> in this patch -- ie. pte_map_nested can go now)
>
> This obviously requires that push and pop are matched, I fixed a few
> cases that were not properly nested, the (x86) code checks for this
> and will go BUG when trying to pop a vaddr that isn't the top one so
> abusers should be rather visible.

Looks great IMO! Last i proposed this i think either Andrew or Avi had
second thoughts about the hard-to-calculate worst-case mapping limit -
but i dont think that's a big issue.

Lets not change the API names though - the rule is that map/unmap must
be properly nested.

Ingo