On 19-Feb-19 16:57, Shiraz Saleem wrote: > This helper iterates through the SG list to find the best page size to use > from a bitmap of HW supported page sizes. Drivers that support multiple > page sizes, but not mixed pages in an MR can use this API. > > Suggested-by: Jason Gunthorpe <jgg@xxxxxxxx> > Reviewed-by: Michael J. Ruhl <michael.j.ruhl@xxxxxxxxx> > Signed-off-by: Shiraz Saleem <shiraz.saleem@xxxxxxxxx> I've tested this patch comparing our existing efa_cont_pages() implementation vs ib_umem_find_single_pg_size() running different test suites: Supported page sizes are anything between 4k to 2G. I'm using page shift to compare results of both functions (ilog2 the return value of ib_umem_find_single_pg_size). When huge pages are disabled, in many cases efa_cont_pages() returns page shift of 13 where ib_umem_find_single_pg_size() returns 12. Didn't see a test where ib_umem_find_single_pg_size() returns anything other than 12 (PAGE_SIZE). When huge pages are enabled, most of the times both functions return the same value (page shift 21/22) but in some cases efa_cont_pages() returns 21 and ib_umem_find_single_pg_size() returns 22 which causes register MR verb to fail due to invalid page address. I simply ran the tests, did not have a chance to debug the issue but it looks like there's an issue with either ib_umem_find_single_pg_size() or the way i used it for EFA.
