On Wed, Nov 16, 2016 at 11:51:32AM +0100, Peter Zijlstra wrote: > On Wed, Nov 16, 2016 at 12:50:21AM +0300, Kirill A. Shutemov wrote: > > On Fri, Nov 04, 2016 at 05:24:57AM +0100, Jan Kara wrote: > > > Currently we have two different structures for passing fault information > > > around - struct vm_fault and struct fault_env. DAX will need more > > > information in struct vm_fault to handle its faults so the content of > > > that structure would become event closer to fault_env. Furthermore it > > > would need to generate struct fault_env to be able to call some of the > > > generic functions. So at this point I don't think there's much use in > > > keeping these two structures separate. Just embed into struct vm_fault > > > all that is needed to use it for both purposes. > > > > > > Signed-off-by: Jan Kara <jack@xxxxxxx> > > > > I'm not necessary dislike this, but I remember Peter had objections before > > when I proposed something similar. > > > > Peter? > > My objection was that it would be a layering violation. The 'filesystem' > shouldn't know about page-tables, all it should do is return a page > matching a specific offset. Well, this layering violation is already there (blame me): see vm_ops->map_pages(). :P > So fault_env manages the core vm parts and has the page-table bits in, > vm_fault manages the filesystem interface and gets us a page given an > offset. > > Now, I'm entirely out of touch wrt DAX, so I've not idea what that > needs/wants. I think we are better off with one structure. It streamlines code in quite a few places. -- Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>