On Tue, Jun 18, 2024 at 10:02:33AM -0300, Jason Gunthorpe wrote: > On Tue, Jun 18, 2024 at 03:08:14PM +0300, Leon Romanovsky wrote: > > > > Set the mkey for dmabuf at PAGE_SIZE to support any SGL > > > > after a move operation. > > > > > > > > ib_umem_find_best_pgsz returns 0 on error, so it is > > > > incorrect to check the returned page_size against PAGE_SIZE > > > > > > This commit message is not clear enough for something that need to be > > > backported: > > > > This patch is going to be backported without any relation to the commit > > message as it has Fixes line. > > People doing backports complain with some regularity about poor commit > messages, especailly now that so many patches get a CVE. We need to do > better. It is always true. > > > > RDMA/mlx5: Support non-page size aligned DMABUF mkeys > > > > > > The mkey page size for DMABUF is fixed at PAGE_SIZE because we have to > > > support a move operation that could change a large-sized page list > > > into a small page-list and the mkey must be able to represent it. > > > > > > The test for this is not quite correct, instead of checking the output > > > of mlx5_umem_find_best_pgsz() the call to ib_umem_find_best_pgsz > > > should specify the exact HW/SW restriction - only PAGE_SIZE is > > > accepted. > > > > > > Then the normal logic for dealing with leading/trailing sub page > > > alignment works correctly and sub page size DMBUF mappings can be > > > supported. > > > > > > This is particularly painful on 64K kernels. > > > > Unfortunately, the patch was already merged, so I can't change the > > commit message in for-next branch. > > How is it already merged? There was no message from your script - are > you loosing emails?? In this specific case, no. I switched too early from branch and my thank-you message (b4 ty ..) simply wasn't sent. Thanks > > Jason
