> On 6 May 2021, at 13:27, Leon Romanovsky <leon@xxxxxxxxxx> wrote:
>
> On Thu, May 06, 2021 at 10:31:44AM +0200, Håkon Bugge wrote:
>> Both the PKEY and GID tables in an HCA can hold in the order of
>> hundreds entries. Reading them are expensive. Partly because the API
>> for retrieving them only returns a single entry at a time. Further, on
>> certain implementations, e.g., CX-3, the VFs are paravirtualized in
>> this respect and have to rely on the PF driver to perform the
>> read. This again demands VF to PF communication.
>>
>> IB Core's cache is refreshed on all events. Hence, filter the refresh
>> of the PKEY and GID caches based on the event received being
>> IB_EVENT_PKEY_CHANGE and IB_EVENT_GID_CHANGE respectively.
>>
>> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
>> Signed-off-by: Håkon Bugge <haakon.bugge@xxxxxxxxxx>
>>
>> ---
>>
>> v1 -> v2:
>> * Changed signature of ib_cache_update() as per Leon's suggestion
>> * Added Fixes tag as per Zhu Yanjun' suggestion
>> ---
>> drivers/infiniband/core/cache.c | 23 +++++++++++++++--------
>> 1 file changed, 15 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/infiniband/core/cache.c b/drivers/infiniband/core/cache.c
>> index 5c9fac7..1493a60 100644
>> --- a/drivers/infiniband/core/cache.c
>> +++ b/drivers/infiniband/core/cache.c
>> @@ -1472,10 +1472,12 @@ static int config_non_roce_gid_cache(struct ib_device *device,
>> }
>>
>> static int
>> -ib_cache_update(struct ib_device *device, u8 port, bool enforce_security)
>> +ib_cache_update(struct ib_device *device, u8 port, bool update_gids,
>> + bool update_pkeys, bool enforce_security)
>> {
>> struct ib_port_attr *tprops = NULL;
>> - struct ib_pkey_cache *pkey_cache = NULL, *old_pkey_cache;
>> + struct ib_pkey_cache *pkey_cache = NULL;
>> + struct ib_pkey_cache *old_pkey_cache = NULL;
>> int i;
>> int ret;
>>
>> @@ -1492,14 +1494,16 @@ static int config_non_roce_gid_cache(struct ib_device *device,
>> goto err;
>> }
>>
>> - if (!rdma_protocol_roce(device, port)) {
>> + if (!rdma_protocol_roce(device, port) && update_gids) {
>
> Can you please elaborate why it is safe to do for IB_EVENT_GID_CHANGE only?
> What about IB_EVENT_CLIENT_REREGISTER?
Client Reregister tells host clients to re-register all subscriptions for said port with the SM. No reason to re-read the GID table in that case.
Or put it another way, when the GID table changes, the channel interface _shall_ generate a GID change event. This per IBTA o11-40.2-1.1.
Thxs, Håkon
>
> Thanks
