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.
Fixes: fad61ad ("IB/core: Add subnet prefix to port info")
Signed-off-by: Anand Khoje <anand.a.khoje@xxxxxxxxxx>
Signed-off-by: Haakon Bugge <haakon.bugge@xxxxxxxxxx>
---
drivers/infiniband/core/device.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index fa20b18..9ad10c8 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -2050,7 +2050,6 @@ static int __ib_query_port(struct ib_device *device,
u32 port_num,
struct ib_port_attr *port_attr)
{
- union ib_gid gid = {};
int err;
memset(port_attr, 0, sizeof(*port_attr));
@@ -2063,11 +2062,9 @@ static int __ib_query_port(struct ib_device *device,
IB_LINK_LAYER_INFINIBAND)
return 0;
- err = device->ops.query_gid(device, port_num, 0, &gid);
- if (err)
- return err;
+ ib_get_cached_subnet_prefix(device, port_num,
+ &port_attr->subnet_prefix);
- port_attr->subnet_prefix = be64_to_cpu(gid.global.subnet_prefix);
return 0;
}
--
1.8.3.1
