On Fri, 9 Oct 2020 14:59:52 -0700 Ralph Campbell <rcampbell@xxxxxxxxxx> wrote: > The code in mc_handle_swap_pte() checks for non_swap_entry() and returns > NULL before checking is_device_private_entry() so device private pages > are never handled. > Fix this by checking for non_swap_entry() after handling device private > swap PTEs. > > Cc: stable@xxxxxxxxxxxxxxx I was going to ask "what are the end-user visible effects of the bug". This is important information with a cc:stable. > > I'm not sure exactly how to test this. I ran the HMM self tests but > that is a minimal sanity check. I think moving the self test from one > memory cgroup to another while it is running would exercise this patch. > I'm looking at how the test could move itself to another group after > migrating some anonymous memory to the test driver. > But this makes me suspect the answer is "there aren't any that we know of". Are you sure a cc:stable is warranted?