path: root/net
diff options
authorEric Dumazet <eric.dumazet@gmail.com>2012-04-10 20:08:39 +0000
committerDavid S. Miller <davem@davemloft.net>2012-04-11 10:10:43 -0400
commit87151b8689d890dfb495081f7be9b9e257f7a2df (patch)
treecb12becc26090b9fd9275f25cee851ffb40d931f /net
parent996304bbea3d2a094b7ba54c3bd65d3fffeac57b (diff)
net: allow pskb_expand_head() to get maximum tailroom
Marc Merlin reported many order-1 allocations failures in TX path on its wireless setup, that dont make any sense with MTU=1500 network, and non SG capable hardware. Turns out part of the problem comes from pskb_expand_head() not using ksize() to get exact head size given by kmalloc(). Doing the same thing than __alloc_skb() allows more tailroom in skb and can prevent future reallocations. As a bonus, struct skb_shared_info becomes cache line aligned. Reported-by: Marc MERLIN <marc@merlins.org> Tested-by: Marc MERLIN <marc@merlins.org> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
1 files changed, 3 insertions, 1 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index baf8d281152c..e59840010d45 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -952,9 +952,11 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
goto adjust_others;
- data = kmalloc(size + sizeof(struct skb_shared_info), gfp_mask);
+ data = kmalloc(size + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)),
+ gfp_mask);
if (!data)
goto nodata;
+ size = SKB_WITH_OVERHEAD(ksize(data));
/* Copy only real data... and, alas, header. This should be
* optimized for the cases when header is void.