summaryrefslogtreecommitdiffstats
path: root/net/ipv4
diff options
context:
space:
mode:
authorAlexander Duyck <alexander.h.duyck@intel.com>2012-05-02 21:18:59 +0000
committerDavid S. Miller <davem@davemloft.net>2012-05-03 04:21:33 -0400
commitc73c3d9c49daae8acbac4cd14bcd81626887c0e6 (patch)
treeb38ef55d8b2cd88a1e02ee9d990c89071edf136c /net/ipv4
parent8c1ae10d792155a7221be12b37dcebc3bcc1b49f (diff)
downloadop-kernel-dev-c73c3d9c49daae8acbac4cd14bcd81626887c0e6.zip
op-kernel-dev-c73c3d9c49daae8acbac4cd14bcd81626887c0e6.tar.gz
tcp: Fix truesize accounting in tcp_try_coalesce
This patch addresses several issues in the way we were tracking the truesize in tcp_try_coalesce. First it was using ksize which prevents us from having a 0 sized head frag and getting a usable result. To resolve that this patch uses the end pointer which is set based off either ksize, or the frag_size supplied in build_skb. This allows us to compute the original truesize of the entire buffer and remove that value leaving us with just what was added as pages. The second issue was the use of skb->len if there is a mergeable head frag. We should only need to remove the size of an data aligned sk_buff from our current skb->truesize to compute the delta for a buffer with a reused head. By using skb->len the value of truesize was being artificially reduced which means that head frags could use more memory than buffers using standard allocations. Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
-rw-r--r--net/ipv4/tcp_input.c10
1 files changed, 4 insertions, 6 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index c6f78e2..3cb273a 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4565,12 +4565,10 @@ merge:
if (skb_headlen(from) == 0 &&
(skb_shinfo(to)->nr_frags +
skb_shinfo(from)->nr_frags <= MAX_SKB_FRAGS)) {
- WARN_ON_ONCE(from->head_frag);
- delta = from->truesize - ksize(from->head) -
- SKB_DATA_ALIGN(sizeof(struct sk_buff));
-
- WARN_ON_ONCE(delta < len);
+ delta = from->truesize -
+ SKB_TRUESIZE(skb_end_pointer(from) - from->head);
copyfrags:
+ WARN_ON_ONCE(delta < len);
memcpy(skb_shinfo(to)->frags + skb_shinfo(to)->nr_frags,
skb_shinfo(from)->frags,
skb_shinfo(from)->nr_frags * sizeof(skb_frag_t));
@@ -4600,7 +4598,7 @@ copyfrags:
skb_fill_page_desc(to, skb_shinfo(to)->nr_frags,
page, offset, skb_headlen(from));
*fragstolen = true;
- delta = len; /* we dont know real truesize... */
+ delta = from->truesize - SKB_DATA_ALIGN(sizeof(struct sk_buff));
goto copyfrags;
}
return false;
OpenPOWER on IntegriCloud