Messages in this thread | | | Subject | Re: [PATCH v3] udp reuseport: fix packet of same flow hashed to different socket | From | Eric Dumazet <> | Date | Sun, 12 Jun 2016 08:32:51 -0700 |
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On Sun, 2016-06-12 at 20:43 +0800, Su Xuemin wrote: > From: "Su, Xuemin" <suxm@chinanetcenter.com> ...
> Signed-off-by: Su, Xuemin <suxm@chinanetcenter.com> > Signed-off-by: Eric Dumazet <edumazet@google.com> > ---
First, I want to thank you for this very high quality submission, especially if this is your first linux kernel patch.
I have one additional comment to make :
> if (score > badness) { > reuseport = sk->sk_reuseport; > @@ -556,14 +510,20 @@ struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, > daddr, hnum, dif, > hslot2, slot2, skb); > if (!result) { > + unsigned int old = hash2; > hash2 = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum); > + > + /* avoid search the same slot again. */ > + if (unlikely(old == hash2)) > + return result; > +
Technically speaking, what matters is the slot, not the hash value (32bit)
So I would save in old, slot2
> slot2 = hash2 & udptable->mask;
And here perform the check if (unlikely(slot2 != old_slot)) return result;
> hslot2 = &udptable->hash2[slot2]; > if (hslot->count < hslot2->count) > goto begin;
(Same remark applies in IPv6)
Thanks !
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