On Sun, Aug 21, 2022 at 11:27:44AM +0100, Matthew Wilcox wrote: > On Thu, Aug 18, 2022 at 08:00:41PM -0700, Hugh Dickins wrote: > > tmpfs and hugetlbfs and page cache are designed around sharing memory: > > TDX is designed around absolutely not sharing memory; and the further > > uses which Sean foresees appear not to need it as page cache either. > > > > Except perhaps for page migration reasons. It's somewhat incidental, > > but of course page migration knows how to migrate page cache, so > > masquerading as page cache will give a short cut to page migration, > > when page migration becomes at all possible. > > I haven't read the patch series, and I'm not taking a position one way > or the other on whether this is better implemented as a shmem addition > or a shim that asks shmem for memory. Page migration can be done for > driver memory by using PageMovable. I just rewrote how it works, so > the details are top of my mind at the moment if anyone wants something > explained. Commit 68f2736a8583 is the key one to look at. Thanks Matthew. That is helpful to understand the current code. Chao
