Before this commit, ixgbe with the default setting lacks XPS mapping
for CPUs id greater than the number of tx queues.
As a consequence the xmit path for such CPUs experience a relevant cost
in __netdev_pick_tx, mainly due to skb_tx_hash(), as reported by the perf
tool:
7.55%--netdev_pick_tx
|
--6.92%--__netdev_pick_tx
|
--6.35%--__skb_tx_hash
|
--5.94%--__skb_get_hash
|
--3.22%--__skb_flow_dissect
in the following scenario:
ethtool -L em1 combined 1
taskset 2 netperf -H 192.168.1.1 -t UDP_STREAM -- -m 1
MIGRATED UDP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.101.1
() port 0 AF_INET
Socket Message Elapsed Messages
Size Size Time Okay Errors Throughput
bytes bytes secs # # 10^6bits/sec
212992 1 10.00 11497225 0 9.20
After this commit the perf tool reports:
0.85%--__netdev_pick_tx
and netperf reports:
MIGRATED UDP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.101.1
() port 0 AF_INET
Socket Message Elapsed Messages
Size Size Time Okay Errors Throughput
bytes bytes secs # # 10^6bits/sec
212992 1 10.00 12736058 0 10.19
roughly +10% in xmit tput.
Signed-off-by: Paolo Abeni <pab...@redhat.com>
---
drivers/net/ethernet/intel/ixgbe/ixgbe.h | 2 +-
drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c | 1 +
drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 13 +++----------
3 files changed, 5 insertions(+), 11 deletions(-)
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe.h
b/drivers/net/ethernet/intel/ixgbe/ixgbe.h
index c1e3a0039ea5..04aaecce81d2 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe.h
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe.h
@@ -293,7 +293,6 @@ enum ixgbe_ring_state_t {
__IXGBE_RX_CSUM_UDP_ZERO_ERR,
__IXGBE_RX_FCOE,
__IXGBE_TX_FDIR_INIT_DONE,
- __IXGBE_TX_XPS_INIT_DONE,
__IXGBE_TX_DETECT_HANG,
__IXGBE_HANG_CHECK_ARMED,
__IXGBE_TX_XDP_RING,
@@ -827,6 +826,7 @@ enum ixgbe_state_t {
__IXGBE_PTP_RUNNING,
__IXGBE_PTP_TX_IN_PROGRESS,
__IXGBE_RESET_REQUESTED,
+ __IXGBE_TX_XPS_INIT_DONE,
};
struct ixgbe_cb {
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
b/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
index c0e6ab42e0e1..da4e6416e8eb 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
@@ -3224,6 +3224,7 @@ static int ixgbe_set_channels(struct net_device *dev,
#endif
/* use setup TC to update any traffic class queue mapping */
+ clear_bit(__IXGBE_TX_XPS_INIT_DONE, &adapter->state);
return ixgbe_setup_tc(dev, adapter->hw_tcs);
}
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 85369423452d..5bd45fc737fa 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -3566,16 +3566,6 @@ void ixgbe_configure_tx_ring(struct ixgbe_adapter
*adapter,
ring->atr_sample_rate = 0;
}
- /* initialize XPS */
- if (!test_and_set_bit(__IXGBE_TX_XPS_INIT_DONE, &ring->state)) {
- struct ixgbe_q_vector *q_vector = ring->q_vector;
-
- if (q_vector)
- netif_set_xps_queue(ring->netdev,
- &q_vector->affinity_mask,
- ring->queue_index);
- }
-
clear_bit(__IXGBE_HANG_CHECK_ARMED, &ring->state);
/* reinitialize tx_buffer_info */
@@ -5626,6 +5616,9 @@ static void ixgbe_up_complete(struct ixgbe_adapter
*adapter)
int err;
u32 ctrl_ext;
+ if (!test_and_set_bit(__IXGBE_TX_XPS_INIT_DONE, &adapter->state))
+ netif_set_xps(adapter->netdev);
+
ixgbe_get_hw_control(adapter);
ixgbe_setup_gpie(adapter);
--
2.14.3
