[PATCH v2 0/4] Sending kernel pathrecord query to user cache server

kaike.wan-ral2JQCrhuEAvxtiuMwx3w
2015-05-19T18:12:02Z

A SA cache is undeniably critical for fabric scalability and performance.
In user space, the ibacm application provides a good example of pathrecord
cache for address and route resolution. With the recent implementation of
the provider architecture, ibacm offers more extensibility as a SA cache.
In kernel, ipoib implements its own small cache for pathrecords, which is
however not available for general use. Furthermore, the implementation of
a SA cache in user space offers better flexibility, larger capacity, and
more robustness for the system.

In this patch series, a mechanism is implemented to allow ib_sa to
send pathrecord query to a user application (eg ibacm) through netlink.
Potentially, this mechanism could be easily extended to other SA queries.

With a customized test implemented in rdma_cm module (not included in this
series), it was shown that the time to retrieve 1 million pathrecords
dropped from 46660 jiffies (46.66 seconds) to 16119 jiffies (or 16.119
seconds) on a two-node system, a reduction of more than 60%.

Changes since v1:
- Move kzalloc changes into a separate patch (Patch 3).
- Remove redundant include line (Patch 4).
- Rename struct rdma_nl_resp_msg as structure ib_nl_resp_msg (Patch 4).

Kaike Wan (4):
IB/netlink: Add defines for MAD requests through netlink
IB/core: Check the presence of netlink multicast group listeners
IB/sa: Allocate SA query with kzalloc
IB/sa: Route SA pathrecord query through netlink

drivers/infiniband/core/netlink.c | 8 +
drivers/infiniband/core/sa_query.c | 333 +++++++++++++++++++++++++++++++++++-
include/rdma/rdma_netlink.h | 7 +
include/uapi/rdma/rdma_netlink.h | 7 +
4 files changed, 350 insertions(+), 5 deletions(-)