From: Anand Khoje <anand.a.khoje@oracle.com>
Date: Mon, 12 Jul 2021 17:56:25 +0530
Subject: IB/core: Read subnet_prefix in ib_query_port via cache.
Patch-mainline: v5.15-rc1
Git-commit: 21bfee9c0c7754408b1f311bffe304caf3e62250
References: jsc#SLE-19249
ib_query_port() calls device->ops.query_port() to get the port
attributes. The method of querying is device driver specific. The same
function calls device->ops.query_gid() to get the GID and extract the
subnet_prefix (gid_prefix).
The GID and subnet_prefix are stored in a cache. But they do not get
read from the cache if the device is an Infiniband device. The
following change takes advantage of the cached subnet_prefix.
Testing with RDBMS has shown a significant improvement in performance
with this change.
Link: https://lore.kernel.org/r/20210712122625.1147-4-anand.a.khoje@oracle.com
Signed-off-by: Anand Khoje <anand.a.khoje@oracle.com>
Signed-off-by: Haakon Bugge <haakon.bugge@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/infiniband/core/device.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -2052,7 +2052,6 @@ static int __ib_query_port(struct ib_dev
u32 port_num,
struct ib_port_attr *port_attr)
{
- union ib_gid gid = {};
int err;
memset(port_attr, 0, sizeof(*port_attr));
@@ -2065,11 +2064,8 @@ static int __ib_query_port(struct ib_dev
IB_LINK_LAYER_INFINIBAND)
return 0;
- err = device->ops.query_gid(device, port_num, 0, &gid);
- if (err)
- return err;
-
- port_attr->subnet_prefix = be64_to_cpu(gid.global.subnet_prefix);
+ ib_get_cached_subnet_prefix(device, port_num,
+ &port_attr->subnet_prefix);
return 0;
}