[PATCH v3 0/3] IB/core: Obtaining subnet_prefix from cache in

From: Anand Khoje
Date: Wed Jun 09 2021 - 01:55:59 EST

This v3 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):
IB/core: Removed port validity check from ib_get_cached_subnet_prefix
IB/core: Shuffle locks in ib_port_data to save memory
IB/core: Obtain subnet_prefix from cache in IB devices.

drivers/infiniband/core/cache.c | 13 +++++++------
drivers/infiniband/core/core_priv.h | 2 +-
drivers/infiniband/core/device.c | 22 +++++++++++++---------
drivers/infiniband/core/security.c | 7 ++-----
include/rdma/ib_cache.h | 6 ++++++
include/rdma/ib_verbs.h | 10 +++++++++-
6 files changed, 38 insertions(+), 22 deletions(-)