From: Willy Tarreau <w@1wt•eu>
To: netdev@vger•kernel.org
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons•com>,
Gregory CLEMENT <gregory.clement@free-electrons•com>,
Eric Dumazet <edumazet@google•com>
Subject: [PATCH] net: convert mvneta to build_skb()
Date: Thu, 4 Jul 2013 19:35:52 +0200 [thread overview]
Message-ID: <20130704173552.GA23370@1wt.eu> (raw)
>From 0180a5e651dd771de18bf2c031ecfe7bb4c88d3e Mon Sep 17 00:00:00 2001
From: Willy Tarreau <w@1wt•eu>
Date: Sat, 15 Jun 2013 23:25:15 +0200
Subject: [PATCH] net: convert mvneta to build_skb()
We store the frag_size in the mvneta_port struct. In practice we'd need
a single bit to know how to free the data, but since we need the size to
call build_skb() anyway, let's store the full size.
With this patch, I observed a reproducible 2% performance improvement on
HTTP-based benchmarks.
Signed-off-by: Willy Tarreau <w@1wt•eu>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons•com>
Cc: Gregory CLEMENT <gregory.clement@free-electrons•com>
Cc: Eric Dumazet <edumazet@google•com>
---
drivers/net/ethernet/marvell/mvneta.c | 71 ++++++++++++++++++++++++-----------
1 file changed, 50 insertions(+), 21 deletions(-)
diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index c966785..0f2c6df 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -225,6 +225,7 @@ struct mvneta_stats {
struct mvneta_port {
int pkt_size;
+ unsigned int frag_size;
void __iomem *base;
struct mvneta_rx_queue *rxqs;
struct mvneta_tx_queue *txqs;
@@ -1259,22 +1260,33 @@ static int mvneta_rx_refill(struct mvneta_port *pp,
{
dma_addr_t phys_addr;
- struct sk_buff *skb;
-
- skb = netdev_alloc_skb(pp->dev, pp->pkt_size);
- if (!skb)
+ void *data;
+ unsigned int skb_size;
+
+ skb_size = SKB_DATA_ALIGN(pp->pkt_size + MVNETA_MH_SIZE + NET_SKB_PAD) +
+ SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+ if (skb_size <= PAGE_SIZE) {
+ data = netdev_alloc_frag(skb_size);
+ pp->frag_size = skb_size;
+ } else {
+ data = kmalloc(skb_size, GFP_ATOMIC);
+ pp->frag_size = 0;
+ }
+ if (!data)
return -ENOMEM;
- phys_addr = dma_map_single(pp->dev->dev.parent, skb->head,
+ phys_addr = dma_map_single(pp->dev->dev.parent, data,
MVNETA_RX_BUF_SIZE(pp->pkt_size),
DMA_FROM_DEVICE);
if (unlikely(dma_mapping_error(pp->dev->dev.parent, phys_addr))) {
- dev_kfree_skb(skb);
+ if (pp->frag_size)
+ put_page(virt_to_head_page(data));
+ else
+ kfree(data);
return -ENOMEM;
}
- mvneta_rx_desc_fill(rx_desc, phys_addr, (u32)skb);
-
+ mvneta_rx_desc_fill(rx_desc, phys_addr, (u32)data);
return 0;
}
@@ -1328,9 +1340,13 @@ static void mvneta_rxq_drop_pkts(struct mvneta_port *pp,
rx_done = mvneta_rxq_busy_desc_num_get(pp, rxq);
for (i = 0; i < rxq->size; i++) {
struct mvneta_rx_desc *rx_desc = rxq->descs + i;
- struct sk_buff *skb = (struct sk_buff *)rx_desc->buf_cookie;
+ void *data = (void *)rx_desc->buf_cookie;
+
+ if (pp->frag_size)
+ put_page(virt_to_head_page(data));
+ else
+ kfree(data);
- dev_kfree_skb_any(skb);
dma_unmap_single(pp->dev->dev.parent, rx_desc->buf_phys_addr,
rx_desc->data_size, DMA_FROM_DEVICE);
}
@@ -1359,6 +1375,7 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo,
while (rx_done < rx_todo) {
struct mvneta_rx_desc *rx_desc = mvneta_rxq_next_desc_get(rxq);
struct sk_buff *skb;
+ unsigned char *data;
u32 rx_status;
int rx_bytes, err;
@@ -1366,14 +1383,14 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo,
rx_done++;
rx_filled++;
rx_status = rx_desc->status;
- skb = (struct sk_buff *)rx_desc->buf_cookie;
+ data = (unsigned char *)rx_desc->buf_cookie;
if (!mvneta_rxq_desc_is_first_last(rx_desc) ||
- (rx_status & MVNETA_RXD_ERR_SUMMARY)) {
+ (rx_status & MVNETA_RXD_ERR_SUMMARY) ||
+ !(skb = build_skb(data, pp->frag_size))) {
dev->stats.rx_errors++;
mvneta_rx_error(pp, rx_desc);
- mvneta_rx_desc_fill(rx_desc, rx_desc->buf_phys_addr,
- (u32)skb);
+ /* leave the descriptor untouched */
continue;
}
@@ -1388,7 +1405,7 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo,
u64_stats_update_end(&pp->rx_stats.syncp);
/* Linux processing */
- skb_reserve(skb, MVNETA_MH_SIZE);
+ skb_reserve(skb, MVNETA_MH_SIZE + NET_SKB_PAD);
skb_put(skb, rx_bytes);
skb->protocol = eth_type_trans(skb, dev);
@@ -1905,12 +1922,21 @@ static int mvneta_rxq_fill(struct mvneta_port *pp, struct mvneta_rx_queue *rxq,
int i;
for (i = 0; i < num; i++) {
- struct sk_buff *skb;
+ void *data;
struct mvneta_rx_desc *rx_desc;
unsigned long phys_addr;
+ unsigned int skb_size;
- skb = dev_alloc_skb(pp->pkt_size);
- if (!skb) {
+ skb_size = SKB_DATA_ALIGN(pp->pkt_size + MVNETA_MH_SIZE + NET_SKB_PAD) +
+ SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+ if (skb_size <= PAGE_SIZE) {
+ data = netdev_alloc_frag(skb_size);
+ pp->frag_size = skb_size;
+ } else {
+ data = kmalloc(skb_size, GFP_ATOMIC);
+ pp->frag_size = 0;
+ }
+ if (!data) {
netdev_err(dev, "%s:rxq %d, %d of %d buffs filled\n",
__func__, rxq->id, i, num);
break;
@@ -1918,15 +1944,18 @@ static int mvneta_rxq_fill(struct mvneta_port *pp, struct mvneta_rx_queue *rxq,
rx_desc = rxq->descs + i;
memset(rx_desc, 0, sizeof(struct mvneta_rx_desc));
- phys_addr = dma_map_single(dev->dev.parent, skb->head,
+ phys_addr = dma_map_single(dev->dev.parent, data,
MVNETA_RX_BUF_SIZE(pp->pkt_size),
DMA_FROM_DEVICE);
if (unlikely(dma_mapping_error(dev->dev.parent, phys_addr))) {
- dev_kfree_skb(skb);
+ if (pp->frag_size)
+ put_page(virt_to_head_page(data));
+ else
+ kfree(data);
break;
}
- mvneta_rx_desc_fill(rx_desc, phys_addr, (u32)skb);
+ mvneta_rx_desc_fill(rx_desc, phys_addr, (u32)data);
}
/* Add this number of RX descriptors as non occupied (ready to
--
1.7.12.2.21.g234cd45.dirty
next reply other threads:[~2013-07-04 17:35 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-04 17:35 Willy Tarreau [this message]
2013-07-04 21:31 ` [PATCH] net: convert mvneta to build_skb() David Miller
2013-07-04 22:12 ` Willy Tarreau
2013-07-05 7:17 ` Thomas Petazzoni
2013-07-05 7:43 ` Willy Tarreau
2013-07-05 7:50 ` Thomas Petazzoni
2013-07-05 8:09 ` Willy Tarreau
2013-07-15 14:34 ` Thomas Petazzoni
2013-07-15 15:12 ` Willy Tarreau
2013-07-15 15:23 ` Thomas Petazzoni
2013-07-15 15:30 ` Willy Tarreau
2013-07-15 15:35 ` Thomas Petazzoni
2013-07-15 15:52 ` Florian Fainelli
2013-07-15 17:01 ` Willy Tarreau
2013-07-15 19:44 ` Thomas Petazzoni
2013-07-15 23:02 ` Florian Fainelli
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