From: Leon Romanovsky <leonro@xxxxxxxxxx> >From Avihai, When an application is not using RDMA CM and if it is using multiple RDMA devices with one or more RoCE ports, finding the right GID table entry is a long process. For example, with two RoCE dual-port devices in a system, when IP failover is used between two RoCE ports, searching a suitable GID entry for a given source IP, matching netdevice of given RoCEv1/v2 type requires iterating over all 4 ports * 256 entry GID table. Even though the best first match GID table for given criteria is used, when the matching entry is on the 4th port, it requires reading 3 ports * 256 entries * 3 files (GID, netdev, type) = 2304 files. The GID table needs to be referred on every QP creation during IP failover on other netdevice of an RDMA device. In an alternative approach, a GID cache may be maintained and updated on GID change event was reported by the kernel. However, it comes with below two limitations: (a) Maintain a thread per application process instance to listen and update the cache. (b) Without the thread, on cache miss event, query the GID table. Even in this approach, if multiple processes are used, a GID cache needs to be maintained on a per-process basis. With a large number of processes, this method doesn't scale. Hence, we introduce this series of patches, which introduces an API to query the complete GID tables of an RDMA device, that returns all valid GID table entries. This is done through single ioctl, eliminating 2304 read, 2304 open and 2304 close system calls to just a total of 2 calls (one for each device). While at it, we also introduce an API to query an individual GID entry over ioctl interface, which provides all GID attributes information. Thanks Avihai Horon (4): RDMA/core: Change rdma_get_gid_attr returned error code RDMA/core: Modify enum ib_gid_type and enum rdma_network_type RDMA/core: Introduce new GID table query API RDMA/uverbs: Expose the new GID query API to user space drivers/infiniband/core/cache.c | 99 +++++++++- drivers/infiniband/core/cma.c | 10 - drivers/infiniband/core/cma_configfs.c | 13 +- drivers/infiniband/core/cma_priv.h | 10 + drivers/infiniband/core/sysfs.c | 3 +- .../infiniband/core/uverbs_std_types_device.c | 180 +++++++++++++++++- drivers/infiniband/core/verbs.c | 2 +- drivers/infiniband/hw/mlx5/cq.c | 2 +- drivers/infiniband/hw/mlx5/main.c | 4 +- drivers/infiniband/hw/qedr/verbs.c | 4 +- include/rdma/ib_cache.h | 5 + include/rdma/ib_verbs.h | 19 +- include/uapi/rdma/ib_user_ioctl_cmds.h | 16 ++ include/uapi/rdma/ib_user_ioctl_verbs.h | 14 ++ 14 files changed, 351 insertions(+), 30 deletions(-) -- 2.26.2
