From: Eric Dumazet <eric.dumazet@gmail.com>
To: "Ilpo Järvinen" <ilpo.jarvinen@helsinki.fi>
Cc: "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 16:10:52 +0200 [thread overview]
Message-ID: <1334844652.2395.187.camel@edumazet-glaptop> (raw)
In-Reply-To: <1334843527.2395.182.camel@edumazet-glaptop>
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...
next prev parent reply other threads:[~2012-04-19 14:10 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 [this message]
2012-04-19 17:20 ` Rick Jones
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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