Re: [PATCH v3 3/6] mm: support THP migration to device private memory

On 11/6/20 12:03 AM, Christoph Hellwig wrote:

I hate the extra pin count magic here. IMHO we really need to finish off the series to get rid of the extra references on the ZONE_DEVICE pages first.

First, thanks for the review comments.

I don't like the extra refcount either, that is why I tried to fix that up before resending this series. However, you didn't like me just fixing the refcount only for device private pages and I don't know the dax/pmem code and peer-to-peer PCIe uses of ZONE_DEVICE pages well enough to say how long it will take me to fix all the use cases. So I wanted to make progress on the THP migration code in the mean time.