On Wed, Oct 30, 2019 at 05:14:30PM -0700, Ralph Campbell wrote: > > Well, that is good, is it also under drivers/char? It kind feels like > > it should not be there... > > I think most of the test modules live in lib/ but I wasn't sure that > was the right place for the HMM test driver. > If you think that is better, I can easily move it. It would be good to get the various test people involved in this, I really don't know. > > > > It seems especially over-complicated to use a full page table layout > > > > for this, wouldn't something simple like an xarray be good enough for > > > > test purposes? > > > > > > Possibly. A page table is really just a lookup table from virtual address > > > to pfn/page. Part of the rationale was to mimic what a real device > > > might do. > > > > Well, but the details of the page table layout don't see really > > important to this testing, IMHO. > > One problem with XArray is that on 32-bit machines the value would > need to be u64 to hold a pfn which won't fit in a ULONG_MAX. > I guess we could make the driver 64-bit only. Why would a 32 bit machine need a 64 bit pfn? Jason