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From: Denys Fedoryshchenko <denys@visp.net.lb>
To: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Cc: netdev@vger.kernel.org, netfilter-devel@vger.kernel.org,
	David Miller <davem@davemloft.net>,
	Eric Dumazet <dada1@cosmosbay.com>
Subject: Re: REDIRECT in nat OUTPUT
Date: Sun, 13 Jul 2008 17:19:50 +0300	[thread overview]
Message-ID: <200807131719.50777.denys@visp.net.lb> (raw)
In-Reply-To: <20080713140930.GA23238@2ka.mipt.ru>

On Sunday 13 July 2008, Evgeniy Polyakov wrote:
> On Sat, Jul 12, 2008 at 05:40:25PM +0300, Denys Fedoryshchenko (denys@visp.net.lb) wrote:
> > Seems i found something. After issuing ethtool -K lo tso on i got significant performance improvement.
> > Why it is not on by default?
> > Without it performance is VERY poor.
> 
> TSO over loopback turns to be GSO, which allows to aggregate multiple
> packets into single frame. If system is not CPU bound, then it is likely
> REDIRECT problem. If I understood you corerctly, loopback performance is
> always good without REDIRECT, but fails to miserable level when
> apprpriate rule is used?
> 
No, seems it has performance issues without redirect(and conntrack unloaded too) even, iperf results on loopback is very unstable.

Actually i dont understand, how on idle machine with Xeon processor iperf over loopback (tcp) can be ~100Mbps?
I think it is a bug.

-- 
------
Technical Manager
Virtual ISP S.A.L.
Lebanon

  reply	other threads:[~2008-07-13 14:19 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-07-12  1:24 REDIRECT in nat OUTPUT Denys Fedoryshchenko
2008-07-12  6:28 ` Evgeniy Polyakov
2008-07-12 13:55   ` Denys Fedoryshchenko
2008-07-12 14:40     ` Denys Fedoryshchenko
2008-07-13 14:09       ` Evgeniy Polyakov
2008-07-13 14:19         ` Denys Fedoryshchenko [this message]
2008-07-13 14:59           ` Krzysztof Oledzki
2008-07-13 15:12             ` Denys Fedoryshchenko

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