From d6bebca92c663fb216c072193945946f3807ca7f Mon Sep 17 00:00:00 2001 From: Changli Gao Date: Tue, 29 Jun 2010 04:39:37 +0000 Subject: fragment: add fast path for in-order fragments add fast path for in-order fragments As the fragments are sent in order in most of OSes, such as Windows, Darwin and FreeBSD, it is likely the new fragments are at the end of the inet_frag_queue. In the fast path, we check if the skb at the end of the inet_frag_queue is the prev we expect. Signed-off-by: Changli Gao ---- include/net/inet_frag.h | 1 + net/ipv4/ip_fragment.c | 12 ++++++++++++ net/ipv6/reassembly.c | 11 +++++++++++ 3 files changed, 24 insertions(+) Signed-off-by: David S. Miller --- net/ipv6/reassembly.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'net/ipv6/reassembly.c') diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c index 0b97230a325..545c4141b75 100644 --- a/net/ipv6/reassembly.c +++ b/net/ipv6/reassembly.c @@ -333,6 +333,11 @@ static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb, * in the chain of fragments so far. We must know where to put * this fragment, right? */ + prev = fq->q.fragments_tail; + if (!prev || FRAG6_CB(prev)->offset < offset) { + next = NULL; + goto found; + } prev = NULL; for(next = fq->q.fragments; next != NULL; next = next->next) { if (FRAG6_CB(next)->offset >= offset) @@ -340,6 +345,7 @@ static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb, prev = next; } +found: /* We found where to put this one. Check for overlap with * preceding fragment, and, if needed, align things so that * any overlaps are eliminated. @@ -397,6 +403,8 @@ static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb, /* Insert this fragment in the chain of fragments. */ skb->next = next; + if (!next) + fq->q.fragments_tail = skb; if (prev) prev->next = skb; else @@ -463,6 +471,8 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, goto out_oom; fp->next = head->next; + if (!fp->next) + fq->q.fragments_tail = fp; prev->next = fp; skb_morph(head, fq->q.fragments); @@ -549,6 +559,7 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS); rcu_read_unlock(); fq->q.fragments = NULL; + fq->q.fragments_tail = NULL; return 1; out_oversize: -- cgit v1.2.3-70-g09d2