On Tue, Apr 12, 2022 at 10:28:21PM +0300, Kirill A. Shutemov wrote: > On Tue, Apr 12, 2022 at 09:39:25PM +0800, Chao Peng wrote: > > On Mon, Apr 11, 2022 at 06:32:33PM +0300, Kirill A. Shutemov wrote: > > > On Thu, Apr 07, 2022 at 04:05:36PM +0000, Sean Christopherson wrote: > > > > Hmm, shmem_writepage() already handles SHM_F_INACCESSIBLE by rejecting the swap, so > > > > maybe it's just the page migration path that needs to be updated? > > > > > > My early version prevented migration with -ENOTSUPP for > > > address_space_operations::migratepage(). > > > > > > What's wrong with that approach? > > > > I previously thought migratepage will not be called since we already > > marked the pages as UNMOVABLE, sounds not correct? > > Do you mean missing __GFP_MOVABLE? Yes. > I can be wrong, but I don't see that it > direclty affects if the page is migratable. It is a hint to page allocator > to group unmovable pages to separate page block and impove availablity of > higher order pages this way. Page allocator tries to allocate unmovable > pages from pages blocks that already have unmovable pages. OK, thanks. Chao > > -- > Kirill A. Shutemov
