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authorEric Dumazet <edumazet@google.com>2012-04-27 02:10:03 +0000
committerDavid S. Miller <davem@davemloft.net>2012-04-30 21:35:50 -0400
commit1d0c0b328a63826b7c80c27d1c4f2b04e8225273 (patch)
tree62b8cb1fcfe51311019d26a4688ef58169ff4362 /net/core
parent329033f645d93b5f9160b9b972dbc5431ad22a33 (diff)
downloadop-kernel-dev-1d0c0b328a63826b7c80c27d1c4f2b04e8225273.zip
op-kernel-dev-1d0c0b328a63826b7c80c27d1c4f2b04e8225273.tar.gz
net: makes skb_splice_bits() aware of skb->head_frag
__skb_splice_bits() can check if skb to be spliced has its skb->head mapped to a page fragment, instead of a kmalloc() area. If so we can avoid a copy of the skb head and get a reference on underlying page. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Maciej Żenczykowski <maze@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Matt Carlson <mcarlson@broadcom.com> Cc: Michael Chan <mchan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/skbuff.c10
1 files changed, 7 insertions, 3 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 09cc386..52ba2b5 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1699,14 +1699,18 @@ static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe,
struct splice_pipe_desc *spd, struct sock *sk)
{
int seg;
+ bool head_is_linear = !skb->head_frag;
- /*
- * map the linear part
+ /* map the linear part :
+ * If skb->head_frag is set, this 'linear' part is backed
+ * by a fragment, and we can avoid a copy.
*/
if (__splice_segment(virt_to_page(skb->data),
(unsigned long) skb->data & (PAGE_SIZE - 1),
skb_headlen(skb),
- offset, len, skb, spd, true, sk, pipe))
+ offset, len, skb, spd,
+ head_is_linear,
+ sk, pipe))
return true;
/*
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