On Wed, Dec 30, 2015 at 12:02 AM, Bob Liu <bob.liu(a)oracle.com> wrote:
On 12/24/2015 03:39 AM, Ross Zwisler wrote:
> Add support for tracking dirty DAX entries in the struct address_space
> radix tree. This tree is already used for dirty page writeback, and it
> already supports the use of exceptional (non struct page*) entries.
> In order to properly track dirty DAX pages we will insert new exceptional
> entries into the radix tree that represent dirty DAX PTE or PMD pages.
I may get it wrong, but there is "struct page" for persistent memory after
"[PATCH v4 00/18]get_user_pages() for dax pte and pmd mappings".
So why not just add "struct page" to radix tree directly just like normal page
Then we don't need to deal with any exceptional entries and special writeback.
That "struct page" is optional and fsync/msync needs to operate in its absence.