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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 11:05:49 -0700	[thread overview]
Message-ID: <4F9053FD.4060509@hp.com> (raw)
In-Reply-To: <1334858436.2395.212.camel@edumazet-glaptop>


>> That or bare ACKs have to be excluded from the overhead checks somehow I
>> guess, or there be more aggressive copying into smaller buffers.
>>
>
> Nope, we need a limit or risk OOM if a malicious peer send ACK flood ;)

Well, there is that...

>
> To be clear, if I change the tcp_rmem[1] from 87380 to big value, I no
> longer have ACK drops, but still poor performance, I am still
> investigating.

What happens if you set net.core.[rw]mem_max to 4 MB and then use 
something like -s 1M -S 1M in netperf?

netperf -t TCP_STREAM -H <remote> -- -s 1M -S 1M -m 64K

(or -m 16K if you want to keep the send size the same as your previous 
tests...)

rick

  reply	other threads:[~2012-04-19 18:05 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
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 [this message]
2012-04-18 19:41           ` [PATCH " Vijay Subramanian
2012-04-18 19:49             ` Eric Dumazet

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