lkml.org 
[lkml]   [2016]   [Nov]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: stmmac ethernet in kernel 4.9-rc6: coalescing related pauses.
Hi!

> What is going on with all these likely()s? Likely new hardware owners
> will not be happy... or anyone running a lot of jumbo frames. (Perhaps
> CPU's branch prediction can do better job here, without explicit hints?)
>
> if (unlikely(is_jumbo) && likely(priv->synopsys_id <
> DWMAC_CORE_4_00)) {

Fix english, remove misleading unlikely's.

Signed-off-by: Pavel Machek <pavel@denx.de>

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index e5a5a05..0363db3 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -2003,7 +2003,7 @@ static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev)
/* Compute header lengths */
proto_hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb);

- /* Desc availability based on threshold should be enough safe */
+ /* Desc availability based on threshold should be safe enough */
if (unlikely(stmmac_tx_avail(priv) <
(((skb->len - proto_hdr_len) / TSO_MAX_BUFF_SIZE + 1)))) {
if (!netif_queue_stopped(dev)) {
@@ -2216,8 +2216,7 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
if (enh_desc)
is_jumbo = priv->hw->mode->is_jumbo_frm(skb->len, enh_desc);

- if (unlikely(is_jumbo) && likely(priv->synopsys_id <
- DWMAC_CORE_4_00)) {
+ if (unlikely(is_jumbo) && priv->synopsys_id < DWMAC_CORE_4_00) {
entry = priv->hw->mode->jumbo_frm(priv, skb, csum_insertion);
if (unlikely(entry < 0))
goto dma_map_err;
@@ -2242,7 +2241,7 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)

priv->tx_skbuff[entry] = NULL;

- if (unlikely(priv->synopsys_id >= DWMAC_CORE_4_00)) {
+ if (priv->synopsys_id >= DWMAC_CORE_4_00) {
desc->des0 = des;
priv->tx_skbuff_dma[entry].buf = desc->des0;
} else {
@@ -2319,7 +2318,7 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
if (dma_mapping_error(priv->device, des))
goto dma_map_err;

- if (unlikely(priv->synopsys_id >= DWMAC_CORE_4_00)) {
+ if (priv->synopsys_id >= DWMAC_CORE_4_00) {
first->des0 = des;
priv->tx_skbuff_dma[first_entry].buf = first->des0;
} else {
@@ -2438,7 +2437,7 @@ static inline void stmmac_rx_refill(struct stmmac_priv *priv)
break;
}

- if (unlikely(priv->synopsys_id >= DWMAC_CORE_4_00)) {
+ if (priv->synopsys_id >= DWMAC_CORE_4_00) {
p->des0 = priv->rx_skbuff_dma[entry];
p->des1 = 0;
} else {
@@ -2455,7 +2454,7 @@ static inline void stmmac_rx_refill(struct stmmac_priv *priv)
}
wmb();

- if (unlikely(priv->synopsys_id >= DWMAC_CORE_4_00))
+ if (priv->synopsys_id >= DWMAC_CORE_4_00)
priv->hw->desc->init_rx_desc(p, priv->use_riwt, 0, 0);
else
priv->hw->desc->set_rx_owner(p);
@@ -2545,7 +2544,7 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit)
int frame_len;
unsigned int des;

- if (unlikely(priv->synopsys_id >= DWMAC_CORE_4_00))
+ if (priv->synopsys_id >= DWMAC_CORE_4_00)
des = p->des0;
else
des = p->des2;

--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2016-11-24 11:37    [W:0.167 / U:8.732 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site