Problems with swapping in v4.5-rc on POWER

[Hugh Dickins]

On Thu, 25 Feb 2016, Aneesh Kumar K.V wrote:
> 
> Can you test the impact of the merge listed below ?(ie, revert the merge and see if
> we can reproduce and also verify with merge applied). This will give us a
> set of commits to look closer. We had quiet a lot of page table
> related changes going in this merge window. 
> 
> f689b742f217b2ffe7 ("Pull powerpc updates from Michael Ellerman:")
> 
> That is the merge commit that added _PAGE_PTE. 

Another experiment running on it at the moment, I'd like to give that
a few more hours, and then will try the revert you suggest.  But does
that merge revert cleanly, did you try?  I'm afraid of interactions,
whether obvious or subtle, with the THP refcounting rework.  Oh, since
I don't have THP configured on, maybe I can ignore any issues from that.

Hugh