* [PATCH v2] net: stmmac: add BQL support
@ 2015-01-21 18:07 Beniamino Galvani
2015-01-21 18:37 ` Eric Dumazet
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Beniamino Galvani @ 2015-01-21 18:07 UTC (permalink / raw)
To: David S. Miller
Cc: Giuseppe Cavallaro, Florian Fainelli, Dave Taht, netdev,
linux-kernel, Beniamino Galvani
Add support for Byte Queue Limits to the STMicro MAC driver.
Tested on a Amlogic S802 quad Cortex-A9 board, where the use of BQL
decreases the latency of a high priority ping from ~12ms to ~1ms when
the 100Mbit link is saturated by 20 TCP streams.
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
---
Changes since v1:
- don't access skb->len after the start of DMA transmission in
stmmac_xmit(), to avoid potential use after free in case tx_lock is
removed in the future
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 118a427..1d74313 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1097,6 +1097,7 @@ static int init_dma_desc_rings(struct net_device *dev, gfp_t flags)
priv->dirty_tx = 0;
priv->cur_tx = 0;
+ netdev_reset_queue(priv->dev);
stmmac_clear_descriptors(priv);
@@ -1300,6 +1301,7 @@ static void stmmac_dma_operation_mode(struct stmmac_priv *priv)
static void stmmac_tx_clean(struct stmmac_priv *priv)
{
unsigned int txsize = priv->dma_tx_size;
+ unsigned int bytes_compl = 0, pkts_compl = 0;
spin_lock(&priv->tx_lock);
@@ -1356,6 +1358,8 @@ static void stmmac_tx_clean(struct stmmac_priv *priv)
priv->hw->mode->clean_desc3(priv, p);
if (likely(skb != NULL)) {
+ pkts_compl++;
+ bytes_compl += skb->len;
dev_consume_skb_any(skb);
priv->tx_skbuff[entry] = NULL;
}
@@ -1364,6 +1368,9 @@ static void stmmac_tx_clean(struct stmmac_priv *priv)
priv->dirty_tx++;
}
+
+ netdev_completed_queue(priv->dev, pkts_compl, bytes_compl);
+
if (unlikely(netif_queue_stopped(priv->dev) &&
stmmac_tx_avail(priv) > STMMAC_TX_THRESH(priv))) {
netif_tx_lock(priv->dev);
@@ -1418,6 +1425,7 @@ static void stmmac_tx_err(struct stmmac_priv *priv)
(i == txsize - 1));
priv->dirty_tx = 0;
priv->cur_tx = 0;
+ netdev_reset_queue(priv->dev);
priv->hw->dma->start_tx(priv->ioaddr);
priv->dev->stats.tx_errors++;
@@ -2048,6 +2056,7 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
if (!priv->hwts_tx_en)
skb_tx_timestamp(skb);
+ netdev_sent_queue(dev, skb->len);
priv->hw->dma->enable_dma_transmission(priv->ioaddr);
spin_unlock(&priv->tx_lock);
--
2.1.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2] net: stmmac: add BQL support
2015-01-21 18:07 [PATCH v2] net: stmmac: add BQL support Beniamino Galvani
@ 2015-01-21 18:37 ` Eric Dumazet
2015-01-22 11:58 ` Giuseppe CAVALLARO
2015-01-26 23:22 ` David Miller
2 siblings, 0 replies; 4+ messages in thread
From: Eric Dumazet @ 2015-01-21 18:37 UTC (permalink / raw)
To: Beniamino Galvani
Cc: David S. Miller, Giuseppe Cavallaro, Florian Fainelli, Dave Taht,
netdev, linux-kernel
On Wed, 2015-01-21 at 19:07 +0100, Beniamino Galvani wrote:
> Add support for Byte Queue Limits to the STMicro MAC driver.
>
> Tested on a Amlogic S802 quad Cortex-A9 board, where the use of BQL
> decreases the latency of a high priority ping from ~12ms to ~1ms when
> the 100Mbit link is saturated by 20 TCP streams.
>
> Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
> ---
> Changes since v1:
> - don't access skb->len after the start of DMA transmission in
> stmmac_xmit(), to avoid potential use after free in case tx_lock is
> removed in the future
>
> drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
Reviewed-by: Eric Dumazet <edumazet@google.com>
Thanks !
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] net: stmmac: add BQL support
2015-01-21 18:07 [PATCH v2] net: stmmac: add BQL support Beniamino Galvani
2015-01-21 18:37 ` Eric Dumazet
@ 2015-01-22 11:58 ` Giuseppe CAVALLARO
2015-01-26 23:22 ` David Miller
2 siblings, 0 replies; 4+ messages in thread
From: Giuseppe CAVALLARO @ 2015-01-22 11:58 UTC (permalink / raw)
To: Beniamino Galvani, David S. Miller
Cc: Florian Fainelli, Dave Taht, netdev, linux-kernel
On 1/21/2015 7:07 PM, Beniamino Galvani wrote:
> Add support for Byte Queue Limits to the STMicro MAC driver.
>
> Tested on a Amlogic S802 quad Cortex-A9 board, where the use of BQL
> decreases the latency of a high priority ping from ~12ms to ~1ms when
> the 100Mbit link is saturated by 20 TCP streams.
>
> Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Ciao Beniamino
thx for the patch, I also see some improvements on my side
Acked-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
> ---
> Changes since v1:
> - don't access skb->len after the start of DMA transmission in
> stmmac_xmit(), to avoid potential use after free in case tx_lock is
> removed in the future
>
> drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index 118a427..1d74313 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -1097,6 +1097,7 @@ static int init_dma_desc_rings(struct net_device *dev, gfp_t flags)
>
> priv->dirty_tx = 0;
> priv->cur_tx = 0;
> + netdev_reset_queue(priv->dev);
>
> stmmac_clear_descriptors(priv);
>
> @@ -1300,6 +1301,7 @@ static void stmmac_dma_operation_mode(struct stmmac_priv *priv)
> static void stmmac_tx_clean(struct stmmac_priv *priv)
> {
> unsigned int txsize = priv->dma_tx_size;
> + unsigned int bytes_compl = 0, pkts_compl = 0;
>
> spin_lock(&priv->tx_lock);
>
> @@ -1356,6 +1358,8 @@ static void stmmac_tx_clean(struct stmmac_priv *priv)
> priv->hw->mode->clean_desc3(priv, p);
>
> if (likely(skb != NULL)) {
> + pkts_compl++;
> + bytes_compl += skb->len;
> dev_consume_skb_any(skb);
> priv->tx_skbuff[entry] = NULL;
> }
> @@ -1364,6 +1368,9 @@ static void stmmac_tx_clean(struct stmmac_priv *priv)
>
> priv->dirty_tx++;
> }
> +
> + netdev_completed_queue(priv->dev, pkts_compl, bytes_compl);
> +
> if (unlikely(netif_queue_stopped(priv->dev) &&
> stmmac_tx_avail(priv) > STMMAC_TX_THRESH(priv))) {
> netif_tx_lock(priv->dev);
> @@ -1418,6 +1425,7 @@ static void stmmac_tx_err(struct stmmac_priv *priv)
> (i == txsize - 1));
> priv->dirty_tx = 0;
> priv->cur_tx = 0;
> + netdev_reset_queue(priv->dev);
> priv->hw->dma->start_tx(priv->ioaddr);
>
> priv->dev->stats.tx_errors++;
> @@ -2048,6 +2056,7 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
> if (!priv->hwts_tx_en)
> skb_tx_timestamp(skb);
>
> + netdev_sent_queue(dev, skb->len);
> priv->hw->dma->enable_dma_transmission(priv->ioaddr);
>
> spin_unlock(&priv->tx_lock);
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] net: stmmac: add BQL support
2015-01-21 18:07 [PATCH v2] net: stmmac: add BQL support Beniamino Galvani
2015-01-21 18:37 ` Eric Dumazet
2015-01-22 11:58 ` Giuseppe CAVALLARO
@ 2015-01-26 23:22 ` David Miller
2 siblings, 0 replies; 4+ messages in thread
From: David Miller @ 2015-01-26 23:22 UTC (permalink / raw)
To: b.galvani; +Cc: peppe.cavallaro, f.fainelli, dave.taht, netdev, linux-kernel
From: Beniamino Galvani <b.galvani@gmail.com>
Date: Wed, 21 Jan 2015 19:07:27 +0100
> Add support for Byte Queue Limits to the STMicro MAC driver.
>
> Tested on a Amlogic S802 quad Cortex-A9 board, where the use of BQL
> decreases the latency of a high priority ping from ~12ms to ~1ms when
> the 100Mbit link is saturated by 20 TCP streams.
>
> Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Applied.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2015-01-27 0:39 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2015-01-21 18:07 [PATCH v2] net: stmmac: add BQL support Beniamino Galvani
2015-01-21 18:37 ` Eric Dumazet
2015-01-22 11:58 ` Giuseppe CAVALLARO
2015-01-26 23:22 ` David Miller
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