From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Chris Friesen" <cfriesen@nortel.com>
Subject: Re: questions on NAPI processing latency and dropped network packets
Date: Mon, 14 Jan 2008 14:02:43 -0600
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Cc: Ray Lee <ray-lk@madrabbit.org>, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org
To: Eric Dumazet <dada1@cosmosbay.com>
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Eric Dumazet wrote:
> Chris Friesen a =C3=A9crit :

>> Based on the profiling information we're spending time in=20
>> sctp_endpoint_lookup_assoc() which doesn't actually use hashes, so I=
=20
>> can't see how the hash would be related.  I'm pretty new to SCTP=20
>> though, so I may be missing something.
>=20
> Well, it does use hashes :)
>=20
>        hash =3D sctp_assoc_hashfn(ep->base.bind_addr.port, rport);
>        head =3D &sctp_assoc_hashtable[hash];
>        read_lock(&head->lock);
>        sctp_for_each_hentry(epb, node, &head->chain) {
>            /* maybe your machine is traversing here a *really* long=20
> chain */
>            }


The latest released kernel doesn't have this code, it was only added in=
=20
November.  The SCTP maintainer just pointed me to the patch, and made=20
some other suggestions as well.

Chris