From: Jiangfeng Xiao <xiaojiangfeng@huawei.com>
Date: Mon, 28 Oct 2019 13:09:46 +0800
Subject: net: hisilicon: Fix ping latency when deal with high throughput
Git-commit: e56bd641ca61beb92b135298d5046905f920b734
Patch-mainline: 5.4-rc6
References: networking-stable-19_11_05
This is due to error in over budget processing.
When dealing with high throughput, the used buffers
that exceeds the budget is not cleaned up. In addition,
it takes a lot of cycles to clean up the used buffer,
and then the buffer where the valid data is located can take effect.
Signed-off-by: Jiangfeng Xiao <xiaojiangfeng@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/net/ethernet/hisilicon/hip04_eth.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
--- a/drivers/net/ethernet/hisilicon/hip04_eth.c
+++ b/drivers/net/ethernet/hisilicon/hip04_eth.c
@@ -173,6 +173,7 @@ struct hip04_priv {
dma_addr_t rx_phys[RX_DESC_NUM];
unsigned int rx_head;
unsigned int rx_buf_size;
+ unsigned int rx_cnt_remaining;
struct device_node *phy_node;
struct phy_device *phy;
@@ -486,7 +487,6 @@ static int hip04_rx_poll(struct napi_str
struct hip04_priv *priv = container_of(napi, struct hip04_priv, napi);
struct net_device *ndev = priv->ndev;
struct net_device_stats *stats = &ndev->stats;
- unsigned int cnt = hip04_recv_cnt(priv);
struct rx_desc *desc;
struct sk_buff *skb;
unsigned char *buf;
@@ -496,8 +496,8 @@ static int hip04_rx_poll(struct napi_str
int tx_remaining;
u16 len;
u32 err;
-
- while (cnt && !last) {
+ priv->rx_cnt_remaining += hip04_recv_cnt(priv);
+ while (priv->rx_cnt_remaining && !last) {
buf = priv->rx_buf[priv->rx_head];
skb = build_skb(buf, priv->rx_buf_size);
if (unlikely(!skb)) {
@@ -543,11 +543,13 @@ refill:
hip04_set_recv_desc(priv, phys);
priv->rx_head = RX_NEXT(priv->rx_head);
- if (rx >= budget)
+ if (rx >= budget) {
+ --priv->rx_cnt_remaining;
goto done;
+ }
- if (--cnt == 0)
- cnt = hip04_recv_cnt(priv);
+ if (--priv->rx_cnt_remaining == 0)
+ priv->rx_cnt_remaining += hip04_recv_cnt(priv);
}
if (!(priv->reg_inten & RCV_INT)) {
@@ -633,6 +635,7 @@ static int hip04_mac_open(struct net_dev
int i;
priv->rx_head = 0;
+ priv->rx_cnt_remaining = 0;
priv->tx_head = 0;
priv->tx_tail = 0;
hip04_reset_ppe(priv);