diff options
| author | Giuseppe Cavallaro <peppe.cavallaro@st.com> | 2016-02-29 14:27:42 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-03-02 14:21:33 -0500 |
| commit | 120e87f91e2980e17356f96055023681f1a4d45b (patch) | |
| tree | f88a91be116063e2029fcd5fab2f6030c38791a5 /drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | |
| parent | 22ad38381547950c64ab8590ebf04a5d3693cbb7 (diff) | |
| download | lwn-120e87f91e2980e17356f96055023681f1a4d45b.tar.gz lwn-120e87f91e2980e17356f96055023681f1a4d45b.zip | |
stmmac: tune rx copy via threshold.
There is a threshold now used to also limit the skb allocation
when use zero-copy. This is to avoid that there are incoherence
in the ring due to a failure on skb allocation under very
aggressive testing and under low memory conditions.
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: Alexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/stmicro/stmmac/stmmac_main.c')
| -rw-r--r-- | drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 26 |
1 files changed, 24 insertions, 2 deletions
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 2ffe8dd9ce99..4c5ce9848ca9 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -72,6 +72,7 @@ module_param(phyaddr, int, S_IRUGO); MODULE_PARM_DESC(phyaddr, "Physical device address"); #define STMMAC_TX_THRESH (DMA_TX_SIZE / 4) +#define STMMAC_RX_THRESH (DMA_RX_SIZE / 4) static int flow_ctrl = FLOW_OFF; module_param(flow_ctrl, int, S_IRUGO | S_IWUSR); @@ -2138,6 +2139,14 @@ static void stmmac_rx_vlan(struct net_device *dev, struct sk_buff *skb) } +static inline int stmmac_rx_threshold_count(struct stmmac_priv *priv) +{ + if (priv->rx_zeroc_thresh < STMMAC_RX_THRESH) + return 0; + + return 1; +} + /** * stmmac_rx_refill - refill used skb preallocated buffers * @priv: driver private structure @@ -2162,8 +2171,15 @@ static inline void stmmac_rx_refill(struct stmmac_priv *priv) struct sk_buff *skb; skb = netdev_alloc_skb_ip_align(priv->dev, bfsize); - if (unlikely(!skb)) + if (unlikely(!skb)) { + /* so for a while no zero-copy! */ + priv->rx_zeroc_thresh = STMMAC_RX_THRESH; + if (unlikely(net_ratelimit())) + dev_err(priv->device, + "fail to alloc skb entry %d\n", + entry); break; + } priv->rx_skbuff[entry] = skb; priv->rx_skbuff_dma[entry] = @@ -2179,9 +2195,13 @@ static inline void stmmac_rx_refill(struct stmmac_priv *priv) priv->hw->mode->refill_desc3(priv, p); + if (priv->rx_zeroc_thresh > 0) + priv->rx_zeroc_thresh--; + if (netif_msg_rx_status(priv)) pr_debug("\trefill entry #%d\n", entry); } + wmb(); priv->hw->desc->set_rx_owner(p); wmb(); @@ -2285,7 +2305,8 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit) frame_len, status); } - if (unlikely(frame_len < priv->rx_copybreak)) { + if (unlikely((frame_len < priv->rx_copybreak) || + stmmac_rx_threshold_count(priv))) { skb = netdev_alloc_skb_ip_align(priv->dev, frame_len); if (unlikely(!skb)) { @@ -2320,6 +2341,7 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit) } prefetch(skb->data - NET_IP_ALIGN); priv->rx_skbuff[entry] = NULL; + priv->rx_zeroc_thresh++; skb_put(skb, frame_len); dma_unmap_single(priv->device, |