On 6/16/2021 1:00 PM, Leon Romanovsky wrote:
On Wed, Jun 16, 2021 at 12:22:13PM +0530, Anand Khoje wrote:
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.
The function ib_cache_is_initialised() is introduced because
ib_query_port() gets called early in the stage when the cache is not
built while reading port immutable property.
In that case, the default GID still gets read from HCA for IB link-
layer devices.
In the situation of an event causing cache update, the subnet_prefix
will get retrieved from newly updated GID cache in ib_cache_update(),
so that we do not end up reading a stale value from cache via
ib_query_port().
Fixes: fad61ad ("IB/core: Add subnet prefix to port info")
Suggested-by: Leon Romanovsky <leonro@xxxxxxxxxx>
Suggested-by: Aru Kolappan <aru.kolappan@xxxxxxxxxx>
Signed-off-by: Anand Khoje <anand.a.khoje@xxxxxxxxxx>
Signed-off-by: Haakon Bugge <haakon.bugge@xxxxxxxxxx>
---
<...>
@@ -1523,13 +1526,21 @@ static int config_non_roce_gid_cache(struct ib_device *device,
device->port_data[port].cache.lmc = tprops->lmc;
device->port_data[port].cache.port_state = tprops->state;
- device->port_data[port].cache.subnet_prefix = tprops->subnet_prefix;
+ ret = rdma_query_gid(device, port, 0, &gid);
+ if (ret) {
+ write_unlock_irq(&device->cache.lock);
And this patch can't compile. It should be cache_lock and not cache.lock.
Thanks
Unfortunate typo from my end. Thanks for pointing this out. I will share
the updated patch.
