Hello!

i try at the moment to figure out why our QDR Infiniband is not
as fast as it should be. So I realized that we use 2k mtu size, and
tried to change this to 4k. But don't now how.

enviroment:
mellanox connectX-3 cards in interlagos machine with sl6.3 64 bit
(RHEL/SL Ofed stack)
mellanox sx6036 switch (4k mtu enabled)

in the mellanox docu i found something about a module parameter
"set_4k_mtu" but this don't work with SL6.3 (unknown parameter)

this also don't work, because there is no "mlx4_port1_mtu"
echo 4096 > /sys/class/infiniband/mlx4_0/device/mlx4_port1_mtu

is it possible that the sl mellanox module don't support 4k mtu?

best regards

sven