ibmvnic: Properly dispose of all skbs during a failover.

During a reset, there may have been transmits in flight that are no
longer valid and cannot be fulfilled.  Resetting and clearing the
queues is insufficient; each skb also needs to be explicitly freed
so that upper levels are not left waiting for confirmation of a
transmit that will never happen.  If this happens frequently enough,
the apparent backlog will cause TCP to begin "congestion control"
unnecessarily, culminating in permanently decreased throughput.

Fixes: d7c0ef36bd ("ibmvnic: Free and re-allocate scrqs when tx/rx scrqs change")
Tested-by: Nick Child <nnac123@linux.ibm.com>
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Rick Lindsley <ricklind@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Rick Lindsley 2022-07-02 03:37:12 -07:00 committed by David S. Miller
parent ea1c3b77bc
commit 1b18f09d31

View File

@ -5981,6 +5981,15 @@ static int ibmvnic_reset_init(struct ibmvnic_adapter *adapter, bool reset)
release_sub_crqs(adapter, 0); release_sub_crqs(adapter, 0);
rc = init_sub_crqs(adapter); rc = init_sub_crqs(adapter);
} else { } else {
/* no need to reinitialize completely, but we do
* need to clean up transmits that were in flight
* when we processed the reset. Failure to do so
* will confound the upper layer, usually TCP, by
* creating the illusion of transmits that are
* awaiting completion.
*/
clean_tx_pools(adapter);
rc = reset_sub_crq_queues(adapter); rc = reset_sub_crq_queues(adapter);
} }
} else { } else {