From: Rick Jones <rick.jones2@hp.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "Ilpo Järvinen" <ilpo.jarvinen@helsinki.fi>,
"Neal Cardwell" <ncardwell@google.com>,
"David Miller" <davem@davemloft.net>,
netdev <netdev@vger.kernel.org>,
"Tom Herbert" <therbert@google.com>,
"Maciej Żenczykowski" <maze@google.com>,
"Yuchung Cheng" <ycheng@google.com>
Subject: Re: [PATCH v2 net-next] tcp: avoid expensive pskb_expand_head() calls
Date: Thu, 19 Apr 2012 10:20:21 -0700 [thread overview]
Message-ID: <4F904955.7070403@hp.com> (raw)
In-Reply-To: <1334844652.2395.187.camel@edumazet-glaptop>
On 04/19/2012 07:10 AM, Eric Dumazet wrote:
> On Thu, 2012-04-19 at 15:52 +0200, Eric Dumazet wrote:
>
>> And disabling GRO on receiver definitely demonstrates the problem, even
>> with a single flow. (and performance drops from 9410 Mbit to 6050 Mbit)
>
> That insane.
>
> Performance drops so much because we _drop_ incoming ACKS :
>
> < TCPSackShifted: 39117
> < TCPSackMerged: 16500
> < TCPSackShiftFallback: 5092
> < TCPBacklogDrop: 27965
> ---
>> TCPSackShifted: 35122
>> TCPSackMerged: 16368
>> TCPSackShiftFallback: 4889
>> TCPBacklogDrop: 23247
>
> Hmm, maybe we should reduce skb->truesize for small packets before
> queueing them in socket backlog...
By copying them to smaller buffers? Or just by altering truesize?
Wasn't the whole point of fixing all the broken truesize settings to
accurately account for memory consumed?
rick
next prev parent reply other threads:[~2012-04-19 17:29 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-17 9:06 [BUG] ixgbe: something wrong with queue selection ? Eric Dumazet
2012-04-17 9:16 ` Jeff Kirsher
2012-04-17 16:01 ` Alexander Duyck
2012-04-17 16:38 ` John Fastabend
2012-04-17 17:07 ` Ben Hutchings
2012-04-17 16:46 ` Eric Dumazet
2012-04-17 21:38 ` TSO not 10G friendly if peer is close enough Eric Dumazet
2012-04-17 21:47 ` David Miller
2012-04-18 3:00 ` Eric Dumazet
2012-04-18 15:49 ` [PATCH net-next] tcp: avoid expensive pskb_expand_head() calls Eric Dumazet
[not found] ` <4F8EF317.10504@hp.com>
2012-04-18 17:16 ` Eric Dumazet
2012-04-18 17:30 ` Rick Jones
2012-04-18 17:40 ` Eric Dumazet
2012-04-18 18:40 ` Neal Cardwell
2012-04-18 19:18 ` Eric Dumazet
2012-04-18 19:51 ` [PATCH v2 " Eric Dumazet
2012-04-19 11:10 ` Ilpo Järvinen
2012-04-19 11:30 ` Eric Dumazet
2012-04-19 11:40 ` Eric Dumazet
2012-04-19 11:57 ` Ilpo Järvinen
2012-04-19 12:44 ` Eric Dumazet
2012-04-20 12:27 ` Ilpo Järvinen
2012-04-19 13:18 ` Eric Dumazet
2012-04-19 13:52 ` Eric Dumazet
2012-04-19 14:10 ` Eric Dumazet
2012-04-19 17:20 ` Rick Jones [this message]
2012-04-19 17:25 ` Eric Dumazet
2012-04-19 17:48 ` Rick Jones
2012-04-19 18:00 ` Eric Dumazet
2012-04-19 18:05 ` Rick Jones
2012-04-18 19:41 ` [PATCH " Vijay Subramanian
2012-04-18 19:49 ` Eric Dumazet
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