Since RHEL6.4 the parameter log_num_mtt of kernel module mlx4_core does no longer provide useful informations

Issue

• Since Red Hat Enterprise Linux (RHEL) 6.4 the parameter log_num_mtt of kernel module mlx4_core does no longer provide useful informations
• since RHEL 6.4 the log_num_mtt parameter in mlx4_core shows no longer useful output:

# on RHEL 6.3:
cat / sys/module/mlx4_core/parameters/log_mtts_per_seg
5
cat / sys/module/mlx4_core/parameters/log_num_mtt
22

# on RHEL 6.4 :
cat / sys/module/mlx4_core/parameters/log_mtts_per_seg
3
cat / sys/module/mlx4_core/parameters/log_num_mtt
0

We use this parameter to calculate the recordable (pinnable) memory.