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| author | Eric Dumazet <edumazet@google.com> | 2012-04-27 02:10:03 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-04-30 21:35:50 -0400 |
| commit | 1d0c0b328a63826b7c80c27d1c4f2b04e8225273 (patch) | |
| tree | 62b8cb1fcfe51311019d26a4688ef58169ff4362 /net/core | |
| parent | 329033f645d93b5f9160b9b972dbc5431ad22a33 (diff) | |
| download | linux-1d0c0b328a63826b7c80c27d1c4f2b04e8225273.tar.gz linux-1d0c0b328a63826b7c80c27d1c4f2b04e8225273.tar.xz linux-1d0c0b328a63826b7c80c27d1c4f2b04e8225273.zip | |
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.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 09cc38651b2f..52ba2b5e803d 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; /* |