From: Long Li <longli@xxxxxxxxxxxxx>
It's inefficient to ring the doorbell page every time a WQE is posted to
the received queue.
Move the code for ringing doorbell page to where after we have posted all
WQEs to the receive queue during a callback from napi_poll().
Tests showed no regression in network latency benchmarks.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: ca9c54d2d6a5 ("net: mana: Add a driver for Microsoft Azure Network Adapter (MANA)")
Signed-off-by: Long Li <longli@xxxxxxxxxxxxx>
---
Change log:
v2:
Check for comp_read > 0 as it might be negative on completion error.
Set rq.wqe_cnt to 0 according to BNIC spec.
drivers/net/ethernet/microsoft/mana/gdma_main.c | 5 ++++-
drivers/net/ethernet/microsoft/mana/mana_en.c | 10 ++++++++--
2 files changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/microsoft/mana/gdma_main.c b/drivers/net/ethernet/microsoft/mana/gdma_main.c
index 8f3f78b68592..ef11d09a3655 100644
--- a/drivers/net/ethernet/microsoft/mana/gdma_main.c
+++ b/drivers/net/ethernet/microsoft/mana/gdma_main.c
@@ -300,8 +300,11 @@ static void mana_gd_ring_doorbell(struct gdma_context *gc, u32 db_index,
void mana_gd_wq_ring_doorbell(struct gdma_context *gc, struct gdma_queue *queue)
{
+ /* BNIC Spec specifies that client should set 0 for rq.wqe_cnt
+ * This value is not used in sq
+ */
mana_gd_ring_doorbell(gc, queue->gdma_dev->doorbell, queue->type,
- queue->id, queue->head * GDMA_WQE_BU_SIZE, 1);
+ queue->id, queue->head * GDMA_WQE_BU_SIZE, 0);
}
void mana_gd_ring_cq(struct gdma_queue *cq, u8 arm_bit)
diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index cd4d5ceb9f2d..1d8abe63fcb8 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -1383,8 +1383,8 @@ static void mana_post_pkt_rxq(struct mana_rxq *rxq)
recv_buf_oob = &rxq->rx_oobs[curr_index];
- err = mana_gd_post_and_ring(rxq->gdma_rq, &recv_buf_oob->wqe_req,
- &recv_buf_oob->wqe_inf);
+ err = mana_gd_post_work_request(rxq->gdma_rq, &recv_buf_oob->wqe_req,
+ &recv_buf_oob->wqe_inf);
if (WARN_ON_ONCE(err))
return;
@@ -1654,6 +1654,12 @@ static void mana_poll_rx_cq(struct mana_cq *cq)
mana_process_rx_cqe(rxq, cq, &comp[i]);
}
+ if (comp_read > 0) {
+ struct gdma_context *gc = rxq->gdma_rq->gdma_dev->gdma_context;
+
+ mana_gd_wq_ring_doorbell(gc, rxq->gdma_rq);
+ }
+
if (rxq->xdp_flush)
xdp_do_flush();
}
--
2.34.1
