From: Tariq Toukan <tar...@mellanox.com>
In the downstream patch that adds support to XDP_REDIRECT-out,
the XDP xmit frame function doesn't share the same run context as
the NAPI that polls the XDP-SQ completion queue.
Hence, need to re-order the XDP-SQ fields to avoid cacheline
false-sharing.
Take redirect_flush and doorbell out of DB, into separated
cachelines.
Add a cacheline breaker within the stats struct.
Signed-off-by: Tariq Toukan <tar...@mellanox.com>
Signed-off-by: Saeed Mahameed <sae...@mellanox.com>
---
drivers/net/ethernet/mellanox/mlx5/core/en.h | 18 +++++++++---------
.../net/ethernet/mellanox/mlx5/core/en/xdp.c | 8 ++++----
.../net/ethernet/mellanox/mlx5/core/en_rx.c | 8 ++++----
.../net/ethernet/mellanox/mlx5/core/en_stats.h | 3 ++-
4 files changed, 19 insertions(+), 18 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h
b/drivers/net/ethernet/mellanox/mlx5/core/en.h
index d9e24fbe6a28..16e219a8f240 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h
@@ -409,22 +409,22 @@ struct mlx5e_xdp_info {
struct mlx5e_xdpsq {
/* data path */
- /* dirtied @rx completion */
+ /* dirtied @completion */
u16 cc;
- u16 pc;
+ bool redirect_flush;
- struct mlx5e_cq cq;
+ /* dirtied @xmit */
+ u16 pc ____cacheline_aligned_in_smp;
+ bool doorbell;
- /* write@xmit, read@completion */
- struct {
- struct mlx5e_xdp_info *xdpi;
- bool doorbell;
- bool redirect_flush;
- } db;
+ struct mlx5e_cq cq;
/* read only */
struct mlx5_wq_cyc wq;
struct mlx5e_xdpsq_stats *stats;
+ struct {
+ struct mlx5e_xdp_info *xdpi;
+ } db;
void __iomem *uar_map;
u32 sqn;
struct device *pdev;
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
index 26e24823504b..eabd5537927d 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
@@ -85,7 +85,7 @@ bool mlx5e_xdp_handle(struct mlx5e_rq *rq, struct
mlx5e_dma_info *di,
if (unlikely(err))
goto xdp_abort;
__set_bit(MLX5E_RQ_FLAG_XDP_XMIT, rq->flags);
- rq->xdpsq.db.redirect_flush = true;
+ rq->xdpsq.redirect_flush = true;
mlx5e_page_dma_unmap(rq, di);
rq->stats->xdp_redirect++;
return true;
@@ -124,10 +124,10 @@ bool mlx5e_xmit_xdp_frame(struct mlx5e_xdpsq *sq, struct
mlx5e_xdp_info *xdpi)
}
if (unlikely(!mlx5e_wqc_has_room_for(wq, sq->cc, sq->pc, 1))) {
- if (sq->db.doorbell) {
+ if (sq->doorbell) {
/* SQ is full, ring doorbell */
mlx5e_xmit_xdp_doorbell(sq);
- sq->db.doorbell = false;
+ sq->doorbell = false;
}
stats->full++;
return false;
@@ -156,7 +156,7 @@ bool mlx5e_xmit_xdp_frame(struct mlx5e_xdpsq *sq, struct
mlx5e_xdp_info *xdpi)
sq->db.xdpi[pi] = *xdpi;
sq->pc++;
- sq->db.doorbell = true;
+ sq->doorbell = true;
stats->xmit++;
return true;
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index 70b984c4e8a4..e33ca03b2100 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -1201,14 +1201,14 @@ int mlx5e_poll_rx_cq(struct mlx5e_cq *cq, int budget)
rq->handle_rx_cqe(rq, cqe);
} while ((++work_done < budget) && (cqe = mlx5_cqwq_get_cqe(&cq->wq)));
- if (xdpsq->db.doorbell) {
+ if (xdpsq->doorbell) {
mlx5e_xmit_xdp_doorbell(xdpsq);
- xdpsq->db.doorbell = false;
+ xdpsq->doorbell = false;
}
- if (xdpsq->db.redirect_flush) {
+ if (xdpsq->redirect_flush) {
xdp_do_flush_map();
- xdpsq->db.redirect_flush = false;
+ xdpsq->redirect_flush = false;
}
mlx5_cqwq_update_db_record(&cq->wq);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.h
b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.h
index 95e1f32c67d9..7aa8ff389cdd 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.h
@@ -230,7 +230,8 @@ struct mlx5e_xdpsq_stats {
u64 xmit;
u64 full;
u64 err;
- u64 cqes;
+ /* dirtied @completion */
+ u64 cqes ____cacheline_aligned_in_smp;
};
struct mlx5e_ch_stats {
--
2.17.0
