README
1This README is for userspace RDMA cm library.
2
3
4Building
5========
6To make this directory, run:
7./autogen.sh && ./configure && make && make install
8
9Typically the autogen and configure steps only need be done the first
10time unless configure.in or Makefile.am changes.
11
12Libraries are installed by default at /usr/local/lib.
13
14
15Device files
16============
17The userspace CMA uses a single device file regardless of the number
18of adapters or ports present.
19
20To create the appropriate character device file automatically with
21udev, a rule like
22
23 KERNEL="rdma_cm", NAME="infiniband/%k", MODE="0666"
24
25can be used. This will create the device node named
26
27 /dev/infiniband/rdma_cm
28
29or you can create it manually
30
31 mknod /dev/infiniband/rdma_cm c 231 255
32
33
34Common issues
35=============
36
37Using multiple interfaces
38 The librdmacm does support multiple interfaces. To make use
39 of multiple interfaces, however, you need to instruct linux
40 to only send ARP reples on the interface targetted in the ARP
41 request. This can be done using a command similar to the
42 following:
43
44 sysctl -w net.ipv4.conf.all.arp_ignore=2
45
46 Without this change, it's possible for linux to resopnd to ARP
47 requests on a different interface (IP address) than the IP
48 address carried in the ARP request. This causes the RDMA stack
49 to incorrectly map the remote IP address to the wrong RDMA
50 device.
51