[PATCH net-next 4/4] net/mlx5e: Rx, Update page pool numa node when changed

[Saeed Mahameed <saeedm@mellanox.com>]

Once every napi poll cycle, check if numa node is different than
the page pool's numa id, and update it using page_pool_update_nid().

Alternatively, we could have registered an irq affinity change handler,
but page_pool_update_nid() must be called from napi context anyways, so
the handler won't actually help.

Performance testing:
XDP drop/tx rate and TCP single/multi stream, on mlx5 driver
while migrating rx ring irq from close to far numa:

mlx5 internal page cache was locally disabled to get pure page pool
results.

CPU: Intel(R) Xeon(R) CPU E5-2603 v4 @ 1.70GHz
NIC: Mellanox Technologies MT27700 Family [ConnectX-4] (100G)

XDP Drop/TX single core:
NUMA  | XDP  | Before    | After
---------------------------------------
Close | Drop | 11   Mpps | 10.8 Mpps
Far   | Drop | 4.4  Mpps | 5.8  Mpps

Close | TX   | 6.5 Mpps  | 6.5 Mpps
Far   | TX   | 4   Mpps  | 3.5  Mpps

Improvement is about 30% drop packet rate, 15% tx packet rate for numa
far test.
No degradation for numa close tests.

TCP single/multi cpu/stream:
NUMA  | #cpu | Before  | After
--------------------------------------
Close | 1    | 18 Gbps | 18 Gbps
Far   | 1    | 15 Gbps | 18 Gbps
Close | 12   | 80 Gbps | 80 Gbps
Far   | 12   | 68 Gbps | 80 Gbps

In all test cases we see improvement for the far numa case, and no
impact on the close numa case.

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_rx.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index d6a547238de0..3b6d55797c0f 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -1386,6 +1386,9 @@ int mlx5e_poll_rx_cq(struct mlx5e_cq *cq, int budget)
 	if (unlikely(!test_bit(MLX5E_RQ_STATE_ENABLED, &rq->state)))
 		return 0;
 
+	if (rq->page_pool)
+		page_pool_nid_changed(rq->page_pool, numa_mem_id());
+
 	if (rq->cqd.left)
 		work_done += mlx5e_decompress_cqes_cont(rq, cqwq, 0, budget);
 
-- 
2.21.0