On Mon, Jan 03, 2022 at 08:26:24PM +0200, Leon Romanovsky wrote: > The proposals are: > 1. Return back to v1, which had dummy umem, so so DM memory regions will > behave as regular user created verbs object. > 2. Add extra flag to is_user/is_kernel for mlx5 mr struct and update all > paths to rely on that flag. > 3. Create separate dereg MR function that will treat DM differently. It is not DM that is the problem, ti is that user and kernel has been mixed together in this mess despite being completely different. I've been slowly disentangling them and the series you just sent 'MR cache enhancment' removes the last blocker from completely giving kernel MRs their own struct. So, the solution here is to move in the direction of making the kernel MRs different. There is only one place that destroys a kernel MR, just have it call a special 'destroy kernel MR' function that doesn't touch any umem stuff at all. Remove the kernel-only parts entirely from the current function. After Aharon's series we can give them different types. Notice the union is already completely disjoint except for the little bit tracking the cache which evaporates once the cache only stores the mkey # and not the struct memory. Jason
