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From: Zoltan Kiss <zoltan.kiss@citrix•com>
To: Eric Dumazet <eric.dumazet@gmail•com>
Cc: Wei Liu <wei.liu2@citrix•com>,
	Jonathan Davies <Jonathan.Davies@eu•citrix.com>,
	Ian Campbell <ian.campbell@citrix•com>, <netdev@vger•kernel.org>,
	<xen-devel@lists•xenproject.org>
Subject: Re: TSQ accounting skb->truesize degrades throughput for large packets
Date: Fri, 6 Sep 2013 17:36:42 +0100	[thread overview]
Message-ID: <522A049A.7000105@citrix.com> (raw)
In-Reply-To: <1378472268.31445.15.camel@edumazet-glaptop>

On 06/09/13 13:57, Eric Dumazet wrote:
> Well, I have no problem to get line rate on 20Gb with a single flow, so
> other drivers have no problem.
I've made some tests on bare metal:
Dell PE R815, Intel 82599EB 10Gb, 3.11-rc4 32 bit kernel with 3.17.3 
ixgbe (TSO, GSO on), iperf 2.0.5
Transmitting packets toward the remote end (so running iperf -c on this 
host) can make 8.3 Gbps with the default 128k tcp_limit_output_bytes. 
When I increased this to 131.506 (128k + 434 bytes) suddenly it jumped 
to 9.4 Gbps. Iperf CPU usage also jumped a few percent from ~36 to ~40% 
(softint percentage in top also increased from ~3 to ~5%)
So I guess it would be good to revisit the default value of this 
setting. What hw you used Eric for your 20Gb results?

Regards,

Zoli

  parent reply	other threads:[~2013-09-06 16:36 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-06 10:16 TSQ accounting skb->truesize degrades throughput for large packets Wei Liu
2013-09-06 12:57 ` Eric Dumazet
2013-09-06 13:12   ` Wei Liu
2013-09-06 16:36   ` Zoltan Kiss [this message]
2013-09-06 16:56     ` Eric Dumazet
2013-09-09  9:27       ` Jason Wang
2013-09-09 13:47         ` Eric Dumazet
2013-09-10  7:45           ` Jason Wang
2013-09-10 12:35             ` Eric Dumazet
2013-09-06 17:00     ` Eric Dumazet
2013-09-07 17:21       ` Eric Dumazet
2013-09-09 21:41         ` Zoltan Kiss
2013-09-09 21:56           ` Eric Dumazet
     [not found]             ` <loom.20130921T045654-573@post.gmane.org>
     [not found]               ` <20130921150327.GA9078@zion.uk.xensource.com>
2013-09-22  2:36                 ` [Xen-devel] " Cong Wang
2013-09-22 14:58                   ` Eric Dumazet
2013-09-27 10:28                     ` [PATCH] tcp: TSQ can use a dynamic limit Eric Dumazet
2013-09-27 15:08                       ` Neal Cardwell
2013-09-29 15:41                       ` Cong Wang
2013-10-01  3:52                       ` David Miller
2013-09-09  5:28       ` TSQ accounting skb->truesize degrades throughput for large packets Cong Wang

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