User Manual

Driver FeaturesRev 2.2-1.0.1
Mellanox Technologies
132
4.16.2 Setting QCN Configuration
Setting the QCN parameters, requires updating its value for each priority. '-1' indicates no change
in the current value.
Example for setting 'rp g_enable' in order to enable QCN for priorities 3, 5, 6:
mlnx_qcn -i eth2 --rpg_enable=-1 -1 -1 1 -1 1 1 -1
Example for setting 'rpg_hai_rate' for priorities 1, 6, 7:
mlnx_qcn -i eth2 --rpg_hai_rate=60 -1 -1 -1 -1 -1 60 60
4.17 CORE-Direct
4.17.1 CORE-Direct Overview
CORE-Direct provides a solution for off loading the MPI collectives operations from the soft-
ware library to the network. CORE-Direct accelerates MPI applications and solves the scalability
issues in lar
ge scale systems by eliminating the issues of operating systems noise and jitter.
It addresses the collectives communication scalability problem by off loading a sequence of data-
dependent communications to the Host Channel
Adapter (HCA). This solution provides the
hooks needed to support computation and communication overlap. Additionally, it provides a
means to reduce the effects of system noise and application skew on application scalability.
The relevant verbs to be used for CORE-Direct:
• ibv_exp_create_qp
• ibv_exp_modify_cq
• ibv_exp_query_device
• ibv_exp_post_task
Samples programs for reference:
• ibv_task_pingpong, ibv_cc_pingpong
4.18 Ethtool
ethtool is a standard Linux utility for controlling network drivers and hardware, particularly for
wired Ethernet devices. It can be used to:
• Get identification and diagnostic information
• Get extended device statistics
• Control speed, duplex, autonegotiation and flow control for Ethernet devices
• Control checksum offload and other hardware offload features
• Control DMA ring sizes and interrupt moderation
rpg_max_rate: 40000
rpg_ai_rate: 10
rpg_hai_rate: 50
rpg_gd: 8
rpg_min_dec_fac: 2
rpg_min_rate: 10
cndd_state_machine: 0