Re: [PATCH net-next] net-next/hinic: Fix a case of Tx Queue is Stopped forever

2017-09-28 Thread David Miller
From: Aviad Krawczyk 
Date: Wed, 27 Sep 2017 02:11:33 +0800

> Fix the following scenario:
> 1. tx_free_poll is running on cpu X
> 2. xmit function is running on cpu Y and fails to get sq wqe
> 3. tx_free_poll frees wqes on cpu X and checks the queue is not stopped
> 4. xmit function stops the queue after failed to get sq wqe
> 5. The queue is stopped forever
> 
> Signed-off-by: Aviad Krawczyk 

Applied.


[PATCH net-next] net-next/hinic: Fix a case of Tx Queue is Stopped forever

2017-09-26 Thread Aviad Krawczyk
Fix the following scenario:
1. tx_free_poll is running on cpu X
2. xmit function is running on cpu Y and fails to get sq wqe
3. tx_free_poll frees wqes on cpu X and checks the queue is not stopped
4. xmit function stops the queue after failed to get sq wqe
5. The queue is stopped forever

Signed-off-by: Aviad Krawczyk 
---
 drivers/net/ethernet/huawei/hinic/hinic_tx.c | 14 --
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/huawei/hinic/hinic_tx.c 
b/drivers/net/ethernet/huawei/hinic/hinic_tx.c
index abe3e38..9128858 100644
--- a/drivers/net/ethernet/huawei/hinic/hinic_tx.c
+++ b/drivers/net/ethernet/huawei/hinic/hinic_tx.c
@@ -212,10 +212,19 @@ netdev_tx_t hinic_xmit_frame(struct sk_buff *skb, struct 
net_device *netdev)
 
sq_wqe = hinic_sq_get_wqe(txq->sq, wqe_size, &prod_idx);
if (!sq_wqe) {
-   tx_unmap_skb(nic_dev, skb, txq->sges);
-
netif_stop_subqueue(netdev, qp->q_id);
 
+   /* Check for the case free_tx_poll is called in another cpu
+* and we stopped the subqueue after free_tx_poll check.
+*/
+   sq_wqe = hinic_sq_get_wqe(txq->sq, wqe_size, &prod_idx);
+   if (sq_wqe) {
+   netif_wake_subqueue(nic_dev->netdev, qp->q_id);
+   goto process_sq_wqe;
+   }
+
+   tx_unmap_skb(nic_dev, skb, txq->sges);
+
u64_stats_update_begin(&txq->txq_stats.syncp);
txq->txq_stats.tx_busy++;
u64_stats_update_end(&txq->txq_stats.syncp);
@@ -223,6 +232,7 @@ netdev_tx_t hinic_xmit_frame(struct sk_buff *skb, struct 
net_device *netdev)
goto flush_skbs;
}
 
+process_sq_wqe:
hinic_sq_prepare_wqe(txq->sq, prod_idx, sq_wqe, txq->sges, nr_sges);
 
hinic_sq_write_wqe(txq->sq, prod_idx, sq_wqe, skb, wqe_size);
-- 
1.9.1