diff options
| author | Eric Dumazet <edumazet@google.com> | 2012-05-17 11:34:16 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-05-17 23:52:40 +0400 |
| commit | a1c7fff7e18f59e684e07b0f9a770561cd39f395 (patch) | |
| tree | 99b006ffc7423205ded8616a21eb955f1fe046dd | |
| parent | 1de5a71c3e6eae2fbf15e9a9e13a8fc269bb82bc (diff) | |
| download | linux-a1c7fff7e18f59e684e07b0f9a770561cd39f395.tar.xz | |
net: netdev_alloc_skb() use build_skb()
netdev_alloc_skb() is used by networks driver in their RX path to
allocate an skb to receive an incoming frame.
With recent skb->head_frag infrastructure, it makes sense to change
netdev_alloc_skb() to use build_skb() and a frag allocator.
This permits a zero copy splice(socket->pipe), and better GRO or TCP
coalescing.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/core/skbuff.c | 32 |
1 files changed, 31 insertions, 1 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 7a10f0894152..7645df1bada0 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -293,6 +293,12 @@ struct sk_buff *build_skb(void *data, unsigned int frag_size) } EXPORT_SYMBOL(build_skb); +struct netdev_alloc_cache { + struct page *page; + unsigned int offset; +}; +static DEFINE_PER_CPU(struct netdev_alloc_cache, netdev_alloc_cache); + /** * __netdev_alloc_skb - allocate an skbuff for rx on a specific device * @dev: network device to receive on @@ -310,8 +316,32 @@ struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int length, gfp_t gfp_mask) { struct sk_buff *skb; + unsigned int fragsz = SKB_DATA_ALIGN(length + NET_SKB_PAD) + + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); - skb = __alloc_skb(length + NET_SKB_PAD, gfp_mask, 0, NUMA_NO_NODE); + if (fragsz <= PAGE_SIZE && !(gfp_mask & __GFP_WAIT)) { + struct netdev_alloc_cache *nc; + void *data = NULL; + + nc = &get_cpu_var(netdev_alloc_cache); + if (!nc->page) { +refill: nc->page = alloc_page(gfp_mask); + nc->offset = 0; + } + if (likely(nc->page)) { + if (nc->offset + fragsz > PAGE_SIZE) { + put_page(nc->page); + goto refill; + } + data = page_address(nc->page) + nc->offset; + nc->offset += fragsz; + get_page(nc->page); + } + put_cpu_var(netdev_alloc_cache); + skb = data ? build_skb(data, fragsz) : NULL; + } else { + skb = __alloc_skb(length + NET_SKB_PAD, gfp_mask, 0, NUMA_NO_NODE); + } if (likely(skb)) { skb_reserve(skb, NET_SKB_PAD); skb->dev = dev; |