[v2,0/3] IB/core: Obtaining subnet_prefix from cache in IB devices.

Message

Anand Khoje June 3, 2021, 6:50 a.m. UTC

This v2 patch series is used to read the port_attribute subnet_prefix 
from a valid cache entry instead of having to call device->ops.query_gid()
in Infiniband link-layer devices. This requires addition of a flag used
to check that the cache entry is initialized and that a valid value
is being read.

1. Removed the port validity check from ib_get_cached_subnet_prefix.
This check was not useful as the port_num is always valid.

2. Shuffled locks pkey_lost_lock and netdev_lock in struct ib_port_data.
This was done to add the 8 byte field flags used for checking the cache
entry validity. Output of pahole showed two 4-byte holes in the structure
ib_port_data after pkey_list_lock and netdev_lock. Moving netdev_lock
shaved off 8 bytes from the structure, which is used to add the 8 byte
field flags in patch 3.

3. Added flags to struct ib_port_data and enum ib_port_data_flags. These
are used to validate the status of cached subnet_prefix. This valid
cache entry of subnet_prefix is used in function __ib_query_port().
This allows the utilization of the cache entry and hence avoids a call
into device->ops.query_gid().

Anand Khoje (3):
  Removed port validity check from ib_get_cached_subnet_prefix
  Shuffle locks in ib_port_data to save memory
  Obtain subnet_prefix from cache in IB devices

 drivers/infiniband/core/cache.c     | 14 ++++++++------
 drivers/infiniband/core/core_priv.h |  2 +-
 drivers/infiniband/core/device.c    | 23 ++++++++++++++---------
 drivers/infiniband/core/security.c  |  7 ++-----
 include/rdma/ib_cache.h             |  6 ++++++
 include/rdma/ib_verbs.h             | 10 +++++++++-
 6 files changed, 40 insertions(+), 22 deletions(-)