On Mon, Aug 10, 2020 at 04:15:50PM +0800, Ruan Shiyang wrote: > > > On 2020/8/7 下午9:38, Matthew Wilcox wrote: > > On Fri, Aug 07, 2020 at 09:13:28PM +0800, Shiyang Ruan wrote: > > > This patchset is a try to resolve the problem of tracking shared page > > > for fsdax. > > > > > > Instead of per-page tracking method, this patchset introduces a query > > > interface: get_shared_files(), which is implemented by each FS, to > > > obtain the owners of a shared page. It returns an owner list of this > > > shared page. Then, the memory-failure() iterates the list to be able > > > to notify each process using files that sharing this page. > > > > > > The design of the tracking method is as follow: > > > 1. dax_assocaite_entry() associates the owner's info to this page > > > > I think that's the first problem with this design. dax_associate_entry is > > a horrendous idea which needs to be ripped out, not made more important. > > It's all part of the general problem of trying to do something on a > > per-page basis instead of per-extent basis. > > > > The memory-failure needs to track owners info from a dax page, so I should > associate the owner with this page. In this version, I associate the block > device to the dax page, so that the memory-failure is able to iterate the > owners by the query interface provided by filesystem. No, it doesn't need to track owner info from a DAX page. What it needs to do is ask the filesystem.
