ip: use rb trees for IP frag queue.

Similar to TCP OOO RX queue, it makes sense to use rb trees to store
IP fragments, so that OOO fragments are inserted faster.

Tested:

- a follow-up patch contains a rather comprehensive ip defrag
  self-test (functional)
- ran neper `udp_stream -c -H <host> -F 100 -l 300 -T 20`:
    netstat --statistics
    Ip:
        282078937 total packets received
        0 forwarded
        0 incoming packets discarded
        946760 incoming packets delivered
        18743456 requests sent out
        101 fragments dropped after timeout
        282077129 reassemblies required
        944952 packets reassembled ok
        262734239 packet reassembles failed
   (The numbers/stats above are somewhat better re:
    reassemblies vs a kernel without this patchset. More
    comprehensive performance testing TBD).

Reported-by: Jann Horn <jannh@google.com>
Reported-by: Juha-Matti Tilli <juha-matti.tilli@iki.fi>
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Peter Oskolkov <posk@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Peter Oskolkov
2018-08-02 23:34:39 +00:00
committed by David S. Miller
parent 385114dec8
commit fa0f527358
6 changed files with 120 additions and 90 deletions

View File

@@ -137,12 +137,16 @@ void inet_frag_destroy(struct inet_frag_queue *q)
fp = q->fragments;
nf = q->net;
f = nf->f;
while (fp) {
struct sk_buff *xp = fp->next;
if (fp) {
do {
struct sk_buff *xp = fp->next;
sum_truesize += fp->truesize;
kfree_skb(fp);
fp = xp;
sum_truesize += fp->truesize;
kfree_skb(fp);
fp = xp;
} while (fp);
} else {
sum_truesize = skb_rbtree_purge(&q->rb_fragments);
}
sum = sum_truesize + f->qsize;