There are several reasons for a TX completion to take longer than usual to be written back by HW. For example, the completion for a packet that misses a rule will have increased latency. The side effect of these variable latencies for any given packet is out of order completions. The stack sends packet X and Y. If packet X takes longer because of the rule miss in the example above, but packet Y hits, it can go on the wire immediately. Which also means it can be completed first. The driver will then receive a completion for packet Y before packet X. The driver will stash the buffers for packet X in a hash table to allow the tx send queue descriptors for both packet X and Y to be reused. The driver will receive the completion for packet X sometime later and have to search the hash table for the associated packet.
The driver cleans packets directly on the ring first, i.e. not out of order completions since they are to some extent considered "slow(er) path". However, certain workloads can increase the frequency of out of order completions thus introducing even more latency into the cleaning path. Bump up the timeout value to account for these workloads. Fixes: 0fe45467a104 ("idpf: add create vport and netdev configuration") Reviewed-by: Sridhar Samudrala <sridhar.samudr...@intel.com> Signed-off-by: Joshua Hay <joshua.a....@intel.com> --- drivers/net/ethernet/intel/idpf/idpf_lib.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/intel/idpf/idpf_lib.c b/drivers/net/ethernet/intel/idpf/idpf_lib.c index f1ee5584e8fa..3d4ae2ed9b96 100644 --- a/drivers/net/ethernet/intel/idpf/idpf_lib.c +++ b/drivers/net/ethernet/intel/idpf/idpf_lib.c @@ -770,8 +770,8 @@ static int idpf_cfg_netdev(struct idpf_vport *vport) else netdev->netdev_ops = &idpf_netdev_ops_singleq; - /* setup watchdog timeout value to be 5 second */ - netdev->watchdog_timeo = 5 * HZ; + /* setup watchdog timeout value to be 30 seconds */ + netdev->watchdog_timeo = 30 * HZ; netdev->dev_port = idx; -- 2.39.2