| Message ID | 1572079779-76449-1-git-send-email-xiaojiangfeng@huawei.com |
|---|---|
| State | Changes Requested |
| Delegated to: | David Miller |
| Headers | show |
| Series | net: hisilicon: Fix ping latency when deal with high throughput | expand |
On Sat, 2019-10-26 at 16:49 +0800, Jiangfeng Xiao wrote: > 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. [] > diff --git a/drivers/net/ethernet/hisilicon/hip04_eth.c b/drivers/net/ethernet/hisilicon/hip04_eth.c [] > @@ -575,7 +575,7 @@ static int hip04_rx_poll(struct napi_struct *napi, int budget) > 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); > + static unsigned int cnt_remaining; static doesn't seem a great idea here as it's for just a single driver instance. Maybe make this part of struct hip04_priv?
From: Jiangfeng Xiao <xiaojiangfeng@huawei.com> Date: Sat, 26 Oct 2019 16:49:39 +0800 > diff --git a/drivers/net/ethernet/hisilicon/hip04_eth.c b/drivers/net/ethernet/hisilicon/hip04_eth.c > index ad6d912..78f338a 100644 > --- a/drivers/net/ethernet/hisilicon/hip04_eth.c > +++ b/drivers/net/ethernet/hisilicon/hip04_eth.c > @@ -575,7 +575,7 @@ static int hip04_rx_poll(struct napi_struct *napi, int budget) > 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); > + static unsigned int cnt_remaining; There is no way a piece of software state should be system wide, this is a per device instance value.
On 2019/10/26 23:44, Joe Perches wrote: > On Sat, 2019-10-26 at 16:49 +0800, Jiangfeng Xiao wrote: >> 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. > [] >> diff --git a/drivers/net/ethernet/hisilicon/hip04_eth.c b/drivers/net/ethernet/hisilicon/hip04_eth.c > [] >> @@ -575,7 +575,7 @@ static int hip04_rx_poll(struct napi_struct *napi, int budget) >> 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); >> + static unsigned int cnt_remaining; > > static doesn't seem a great idea here as it's for just a single > driver instance. Maybe make this part of struct hip04_priv? > Thank you for your review. Your suggestion is very good.
On 2019/10/27 2:22, David Miller wrote: > From: Jiangfeng Xiao <xiaojiangfeng@huawei.com> > Date: Sat, 26 Oct 2019 16:49:39 +0800 > >> diff --git a/drivers/net/ethernet/hisilicon/hip04_eth.c b/drivers/net/ethernet/hisilicon/hip04_eth.c >> index ad6d912..78f338a 100644 >> --- a/drivers/net/ethernet/hisilicon/hip04_eth.c >> +++ b/drivers/net/ethernet/hisilicon/hip04_eth.c >> @@ -575,7 +575,7 @@ static int hip04_rx_poll(struct napi_struct *napi, int budget) >> 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); >> + static unsigned int cnt_remaining; > > There is no way a piece of software state should be system wide, this is > a per device instance value. > > . > Thank you for your guidance, I will fix it in v2.
diff --git a/drivers/net/ethernet/hisilicon/hip04_eth.c b/drivers/net/ethernet/hisilicon/hip04_eth.c index ad6d912..78f338a 100644 --- a/drivers/net/ethernet/hisilicon/hip04_eth.c +++ b/drivers/net/ethernet/hisilicon/hip04_eth.c @@ -575,7 +575,7 @@ static int hip04_rx_poll(struct napi_struct *napi, int budget) 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); + static unsigned int cnt_remaining; struct rx_desc *desc; struct sk_buff *skb; unsigned char *buf; @@ -588,8 +588,8 @@ static int hip04_rx_poll(struct napi_struct *napi, int budget) /* clean up tx descriptors */ tx_remaining = hip04_tx_reclaim(ndev, false); - - while (cnt && !last) { + cnt_remaining += hip04_recv_cnt(priv); + while (cnt_remaining && !last) { buf = priv->rx_buf[priv->rx_head]; skb = build_skb(buf, priv->rx_buf_size); if (unlikely(!skb)) { @@ -635,11 +635,13 @@ static int hip04_rx_poll(struct napi_struct *napi, int budget) hip04_set_recv_desc(priv, phys); priv->rx_head = RX_NEXT(priv->rx_head); - if (rx >= budget) + if (rx >= budget) { + --cnt_remaining; goto done; + } - if (--cnt == 0) - cnt = hip04_recv_cnt(priv); + if (--cnt_remaining == 0) + cnt_remaining += hip04_recv_cnt(priv); } if (!(priv->reg_inten & RCV_INT)) {
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> --- drivers/net/ethernet/hisilicon/hip04_eth.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)