On 5/13/2020 4:43 AM, Max Gurtovoy wrote:
On 5/12/2020 11:09 PM, Bart Van Assche wrote:
On 2020-05-12 10:16, Leon Romanovsky wrote:
On Tue, May 12, 2020 at 07:08:59PM +0300, Israel Rukshin wrote:
FMR is not supported on most recent RDMA devices (that use fast memory
registration mechanism). Also, FMR was recently removed from NFS/RDMA
ULP.
Signed-off-by: Israel Rukshin <israelr@xxxxxxxxxxxx>
Signed-off-by: Max Gurtovoy <maxg@xxxxxxxxxxxx>
---
drivers/infiniband/ulp/iser/iscsi_iser.h | 79 +----------
drivers/infiniband/ulp/iser/iser_initiator.c | 19 ++-
drivers/infiniband/ulp/iser/iser_memory.c | 188
++-------------------------
drivers/infiniband/ulp/iser/iser_verbs.c | 126 +++---------------
4 files changed, 40 insertions(+), 372 deletions(-)
Can we do an extra step and remove FMR from srp too?
Which HCA's will be affected by removing FMR support? Or in other words,
when did (Mellanox) HCA's start supporting fast memory registration? I'm
asking this because there is a tradition in the Linux kernel not to
remove support for old hardware unless it is pretty sure that nobody is
using that hardware anymore.
ConnectX-3 and above supports fast memory registrations.
Which, to be clear, is FRWR, and different from FMR.
FMR is ancient and was a ConnectX-2 feature IIRC. It was basically
a proprietary firmware API implemented by directly stuffing commands
into the HCA. And as previously pointed out, insecure and fragile.
Honestly, I thought it was already removed!
Tom.
