And drop bits that are outdated or replaced by top-level Documentation. Signed-off-by: Christoph Hellwig <hch@xxxxxx> --- Documentation/librdmacm.md | 46 ++++++++++++++++++++++++++++++++++ librdmacm/README | 61 ---------------------------------------------- 2 files changed, 46 insertions(+), 61 deletions(-) create mode 100644 Documentation/librdmacm.md delete mode 100644 librdmacm/README diff --git a/Documentation/librdmacm.md b/Documentation/librdmacm.md new file mode 100644 index 0000000..5eb8d31 --- /dev/null +++ b/Documentation/librdmacm.md @@ -0,0 +1,46 @@ +# Device files + +The userspace CMA uses a single device file regardless of the number +of adapters or ports present. + +To create the appropriate character device file automatically with +udev, a rule like + + KERNEL="rdma_cm", NAME="infiniband/%k", MODE="0666" + +can be used. This will create the device node named + + /dev/infiniband/rdma_cm + +or you can create it manually + + mknod /dev/infiniband/rdma_cm c 231 255 + + +# Common issues + +Using multiple interfaces + The librdmacm does support multiple interfaces. To make use + of multiple interfaces, however, you need to instruct linux + to only send ARP reples on the interface targetted in the ARP + request. This can be done using a command similar to the + following: + + sysctl -w net.ipv4.conf.all.arp_ignore=2 + + Without this change, it's possible for linux to resopnd to ARP + requests on a different interface (IP address) than the IP + address carried in the ARP request. This causes the RDMA stack + to incorrectly map the remote IP address to the wrong RDMA + device. + +Using loopback + The librdmacm relies on ARP to resolve IP address to RDMA + addresses. To support loopback connections between different + ports on the same system, ARP must be enabled for local + resolution: + + sysctl net.ipv4.conf.all.accept_local=1 + + Without this setting, loopback connections may timeout + during address resolution. diff --git a/librdmacm/README b/librdmacm/README deleted file mode 100644 index e1f2227..0000000 --- a/librdmacm/README +++ /dev/null @@ -1,61 +0,0 @@ -This README is for userspace RDMA cm library. - - -Building -======== -To make this directory, run: -./autogen.sh && ./configure && make && make install - -Typically the autogen and configure steps only need be done the first -time unless configure.in or Makefile.am changes. - -Libraries are installed by default at /usr/local/lib. - - -Device files -============ -The userspace CMA uses a single device file regardless of the number -of adapters or ports present. - -To create the appropriate character device file automatically with -udev, a rule like - - KERNEL="rdma_cm", NAME="infiniband/%k", MODE="0666" - -can be used. This will create the device node named - - /dev/infiniband/rdma_cm - -or you can create it manually - - mknod /dev/infiniband/rdma_cm c 231 255 - - -Common issues -============= - -Using multiple interfaces - The librdmacm does support multiple interfaces. To make use - of multiple interfaces, however, you need to instruct linux - to only send ARP reples on the interface targetted in the ARP - request. This can be done using a command similar to the - following: - - sysctl -w net.ipv4.conf.all.arp_ignore=2 - - Without this change, it's possible for linux to resopnd to ARP - requests on a different interface (IP address) than the IP - address carried in the ARP request. This causes the RDMA stack - to incorrectly map the remote IP address to the wrong RDMA - device. - -Using loopback - The librdmacm relies on ARP to resolve IP address to RDMA - addresses. To support loopback connections between different - ports on the same system, ARP must be enabled for local - resolution: - - sysctl net.ipv4.conf.all.accept_local=1 - - Without this setting, loopback connections may timeout - during address resolution. -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
