User Manual
Table Of Contents
- Mellanox WinOF VPI User Manual
- Table of Contents
- List of Tables
- Document Revision History
- About this Manual
- 1 Introduction
- 2 Driver Features
- 3 Deploying Windows Server 2012 with SMB Direct
- 4 Driver Configuration
- 5 Performance Tuning
- 6 OpenSM - Subnet Manager
- 7 InfiniBand Fabric
- 7.1 Network Direct Interface
- 7.2 part_man - Virtual IPoIB Port Creation Utility
- 7.3 InfiniBand Fabric Diagnostic Utilities
- 7.4 InfiniBand Fabric Performance Utilities
- 7.4.1 ib_read_bw
- 7.4.2 ib_read_lat
- 7.4.3 ib_send_bw
- 7.4.4 ib_send_lat
- 7.4.5 ib_write_bw
- 7.4.6 ib_write_lat
- 7.4.7 ibv_read_bw
- 7.4.8 ibv_read_lat
- 7.4.9 ibv_send_bw
- 7.4.10 ibv_send_lat
- 7.4.11 ibv_write_bw
- 7.4.12 ibv_write_lat
- 7.4.13 ibaddr
- 7.4.14 ibcacheedit
- 7.4.15 iblinkinfo
- 7.4.16 ibqueryerrors
- 7.4.17 ibsysstat
- 7.4.18 perfquery
- 7.4.19 saquery
- 7.4.20 smpdump
- 8 Software Development Kit
- 9 Troubleshooting
- 10 Documentation
WinOF VPI for Windows User Manual Rev 4.3
Mellanox Technologies
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7.4.8 ibv_read_lat
This is a more advanced version of ib_read_lat ,and contains more flags and featurs than the
older version and also improved algorithms. ibv_read_lat calculats the latency of RDMA read
operation of message_sizeB between a pair of machines. One acts as a server and the other as a
client. They perform a ping pong benchmark on which one side RDMA reads the memory of
the other side only after the other side have read his memory. Each of the sides samples the CPU
clock each time they read the other side memory, to calculate latency. Read is availible only in
RC connection mode (as specified in InfiniBand spec).
7.4.8.1 ibv_read_lat Synopsys
7.4.8.2 ibv_read_lat Options
The table below lists the various flags of the command.
-Q, --cq-mod Generate Cqe only after <--cq-mod> completion
-N, --no peak-bw Cancel peak-bw calculation (default with peak)
ibv_read_lat [-i(b_port) ib_port] [-m(tu) mtu_size] [-s(ize) message_size] [-t(x-
depth) tx_size] [-I(nline_size) inline size] [-u qp timeout] [-S(L) sl type] [-d
ib_device name] [-x gid index] [-n iteration_num] [-o(uts)
outstanding reads] [-e(vents) use events] [-
p(ort) PDT_port] [-a(ll)] [-V(ersion)] [-C report cycles] [-H
report histogram] [-U report unsorted] [-F CPU freq fail]
Table 25 - ibv_read_lat Flags and Options
Flag Description
-p, --port=<port> Listens on/connect to port <port> (default 18515)
-d, --ib-dev=<dev> Uses IB device <device guid> (default first device found)
-i, --ib-port=<port> Uses port <port> of IB device (default 1)
-m, --mtu=<mtu> The mtu size (default 1024)
-o, --outs=<num> The number of outstanding read/atom(default for hermon 16 (others
4)
-s, --size=<size> The size of message to exchange (default 65536)
-a, --all Runs sizes from 2 till 2^23
-t, --tx-depth=<dep> The size of tx queue (default 100)
-n, --iters=<iters> The number of exchanges (at least 2, default 1000)
-u, --qp-timeout=<timeout> QP timeout. The timeout value is 4 usec * 2 ^(timeout), default 14
-S, --sl=<sl> The service level (default 0)
Table 24 - ibv_read_bw Flags and Options
Flag Description