On Tue, Sep 01, 2020 at 09:43:29PM -0300, Jason Gunthorpe wrote:
> It is possible for a single SGL to span an aligned boundary, eg if the SGL
> is
>
> 61440 -> 90112
>
> Then the length is 28672, which currently limits the block size to
> 32k. With a 32k page size the two covering blocks will be:
>
> 32768->65536 and 65536->98304
>
> However, the correct answer is a 128K block size which will span the whole
> 28672 bytes in a single block.
>
> Instead of limiting based on length figure out which high IOVA bits don't
> change between the start and end addresses. That is the highest useful
> page size.
>
> Fixes: 4a35339958f1 ("RDMA/umem: Add API to find best driver supported page size in an MR")
> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> ---
> drivers/infiniband/core/umem.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
Thanks,
Reviewed-by: Leon Romanovsky <leonro@xxxxxxxxxx>
