On Fri, Feb 12, 2016 at 10:33:37AM -0800, Dave Hansen wrote: > On 02/11/2016 06:21 AM, Kirill A. Shutemov wrote: > > For file pages we don't deposit page table on mapping: no need to > > withdraw it. > > I thought the deposit thing was to guarantee we could always do a PMD > split. It still seems like if you wanted to split a huge-tmpfs page, > you'd need to first split the PMD which might need the deposited one. > > Why not?
For file thp, split_huge_pmd() is implemented by clearing out the pmd: we can setup and fill pte table later. Therefore no need to deposit page table -- we would not use it. DAX does the same. -- Kirill A. Shutemov
