[PATCH 11/29] net: packet split receive api

From: Peter Zijlstra
Date: Wed Feb 21 2007 - 10:37:06 EST


Add some packet-split receive hooks.

For one this allows to do NUMA node affine page allocs. Later on these hooks
will be extended to do emergency reserve allocations for fragments.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
---
drivers/net/e1000/e1000_main.c | 8 ++------
drivers/net/sky2.c | 16 ++++++----------
include/linux/skbuff.h | 23 +++++++++++++++++++++++
net/core/skbuff.c | 20 ++++++++++++++++++++
4 files changed, 51 insertions(+), 16 deletions(-)

Index: linux-2.6-git/drivers/net/e1000/e1000_main.c
===================================================================
--- linux-2.6-git.orig/drivers/net/e1000/e1000_main.c 2007-02-14 08:31:12.000000000 +0100
+++ linux-2.6-git/drivers/net/e1000/e1000_main.c 2007-02-14 11:42:07.000000000 +0100
@@ -4412,12 +4412,8 @@ e1000_clean_rx_irq_ps(struct e1000_adapt
pci_unmap_page(pdev, ps_page_dma->ps_page_dma[j],
PAGE_SIZE, PCI_DMA_FROMDEVICE);
ps_page_dma->ps_page_dma[j] = 0;
- skb_fill_page_desc(skb, j, ps_page->ps_page[j], 0,
- length);
+ skb_add_rx_frag(skb, j, ps_page->ps_page[j], 0, length);
ps_page->ps_page[j] = NULL;
- skb->len += length;
- skb->data_len += length;
- skb->truesize += length;
}

/* strip the ethernet crc, problem is we're using pages now so
@@ -4623,7 +4619,7 @@ e1000_alloc_rx_buffers_ps(struct e1000_a
if (j < adapter->rx_ps_pages) {
if (likely(!ps_page->ps_page[j])) {
ps_page->ps_page[j] =
- alloc_page(GFP_ATOMIC);
+ netdev_alloc_page(netdev);
if (unlikely(!ps_page->ps_page[j])) {
adapter->alloc_rx_buff_failed++;
goto no_buffers;
Index: linux-2.6-git/include/linux/skbuff.h
===================================================================
--- linux-2.6-git.orig/include/linux/skbuff.h 2007-02-14 11:29:54.000000000 +0100
+++ linux-2.6-git/include/linux/skbuff.h 2007-02-14 11:59:04.000000000 +0100
@@ -813,6 +813,9 @@ static inline void skb_fill_page_desc(st
skb_shinfo(skb)->nr_frags = i + 1;
}

+extern void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page,
+ int off, int size);
+
#define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
#define SKB_FRAG_ASSERT(skb) BUG_ON(skb_shinfo(skb)->frag_list)
#define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
@@ -1148,6 +1151,26 @@ static inline struct sk_buff *netdev_all
return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
}

+extern struct page *__netdev_alloc_page(struct net_device *dev, gfp_t gfp_mask);
+
+/**
+ * netdev_alloc_page - allocate a page for ps-rx on a specific device
+ * @dev: network device to receive on
+ *
+ * Allocate a new page node local to the specified device.
+ *
+ * %NULL is returned if there is no free memory.
+ */
+static inline struct page *netdev_alloc_page(struct net_device *dev)
+{
+ return __netdev_alloc_page(dev, GFP_ATOMIC);
+}
+
+static inline void netdev_free_page(struct net_device *dev, struct page *page)
+{
+ __free_page(page);
+}
+
/**
* skb_cow - copy header of skb when it is required
* @skb: buffer to cow
Index: linux-2.6-git/net/core/skbuff.c
===================================================================
--- linux-2.6-git.orig/net/core/skbuff.c 2007-02-14 11:29:54.000000000 +0100
+++ linux-2.6-git/net/core/skbuff.c 2007-02-14 12:01:40.000000000 +0100
@@ -279,6 +279,24 @@ struct sk_buff *__netdev_alloc_skb(struc
return skb;
}

+struct page *__netdev_alloc_page(struct net_device *dev, gfp_t gfp_mask)
+{
+ int node = dev->dev.parent ? dev_to_node(dev->dev.parent) : -1;
+ struct page *page;
+
+ page = alloc_pages_node(node, gfp_mask, 0);
+ return page;
+}
+
+void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off,
+ int size)
+{
+ skb_fill_page_desc(skb, i, page, off, size);
+ skb->len += size;
+ skb->data_len += size;
+ skb->truesize += size;
+}
+
static void skb_drop_list(struct sk_buff **listp)
{
struct sk_buff *list = *listp;
@@ -2066,6 +2084,8 @@ EXPORT_SYMBOL(kfree_skb);
EXPORT_SYMBOL(__pskb_pull_tail);
EXPORT_SYMBOL(__alloc_skb);
EXPORT_SYMBOL(__netdev_alloc_skb);
+EXPORT_SYMBOL(__netdev_alloc_page);
+EXPORT_SYMBOL(skb_add_rx_frag);
EXPORT_SYMBOL(pskb_copy);
EXPORT_SYMBOL(pskb_expand_head);
EXPORT_SYMBOL(skb_checksum);
Index: linux-2.6-git/drivers/net/sky2.c
===================================================================
--- linux-2.6-git.orig/drivers/net/sky2.c 2007-02-14 08:31:12.000000000 +0100
+++ linux-2.6-git/drivers/net/sky2.c 2007-02-14 12:00:22.000000000 +0100
@@ -1083,7 +1083,7 @@ static struct sk_buff *sky2_rx_alloc(str
skb_reserve(skb, ALIGN(p, RX_SKB_ALIGN) - p);

for (i = 0; i < sky2->rx_nfrags; i++) {
- struct page *page = alloc_page(GFP_ATOMIC);
+ struct page *page = netdev_alloc_page(sky2->netdev);

if (!page)
goto free_partial;
@@ -1972,8 +1972,8 @@ static struct sk_buff *receive_copy(stru
}

/* Adjust length of skb with fragments to match received data */
-static void skb_put_frags(struct sk_buff *skb, unsigned int hdr_space,
- unsigned int length)
+static void skb_put_frags(struct sky2_port *sky2, struct sk_buff *skb,
+ unsigned int hdr_space, unsigned int length)
{
int i, num_frags;
unsigned int size;
@@ -1990,15 +1990,11 @@ static void skb_put_frags(struct sk_buff

if (length == 0) {
/* don't need this page */
- __free_page(frag->page);
+ netdev_free_page(sky2->netdev, frag->page);
--skb_shinfo(skb)->nr_frags;
} else {
size = min(length, (unsigned) PAGE_SIZE);
-
- frag->size = size;
- skb->data_len += size;
- skb->truesize += size;
- skb->len += size;
+ skb_add_rx_frag(skb, i, frag->page, 0, size);
length -= size;
}
}
@@ -2027,7 +2023,7 @@ static struct sk_buff *receive_new(struc
sky2_rx_map_skb(sky2->hw->pdev, re, hdr_space);

if (skb_shinfo(skb)->nr_frags)
- skb_put_frags(skb, hdr_space, length);
+ skb_put_frags(sky2, skb, hdr_space, length);
else
skb_put(skb, length);
return skb;

--

-
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