Hi Alistair,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on s390/features]
[also build test ERROR on linus/master v5.12-rc2 next-20210309]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as
Some devices require exclusive write access to shared virtual
memory (SVM) ranges to perform atomic operations on that memory. This
requires CPU page tables to be updated to deny access whilst atomic
operations are occurring.
In order to do this introduce a new swap entry
type (SWP_DEVICE_EXCLUSIV