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From: Eric Dumazet <eric.dumazet@gmail.com>
To: Ming Lei <tom.leiming@gmail.com>
Cc: Network Development <netdev@vger.kernel.org>,
	David Miller <davem@davemloft.net>
Subject: Re: TCP transmit performance regression
Date: Thu, 05 Jul 2012 10:33:12 +0200	[thread overview]
Message-ID: <1341477192.2583.3415.camel@edumazet-glaptop> (raw)
In-Reply-To: <CACVXFVNxcdEYd-KmkUe9=8+x_9s-ZVuoM=FfZ=QXa7w_qRiTnw@mail.gmail.com>

On Thu, 2012-07-05 at 16:27 +0800, Ming Lei wrote:

> After some investigation, the problem is caused by enabling
> DEBUG_SLAB, so it is not a regression.
> 

Strange, unless your machine is a _very_ slow one maybe ?

> 
> Looks no improvement. I still don't know why the window size becomes so
> small even in good situation(disabling DEBUG_SLAB), and the small
> window size will cause almost every tcp data packet acked.

You are probably missing the fact that window scaling is enabled.

If you dont post a pcap, I am afraid we cant really help.

  reply	other threads:[~2012-07-05  8:33 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-05  1:45 TCP transmit performance regression Ming Lei
2012-07-05  7:43 ` Eric Dumazet
2012-07-05  8:27   ` Ming Lei
2012-07-05  8:33     ` Eric Dumazet [this message]
2012-07-05  8:42       ` Ming Lei
2012-07-05  9:49         ` Eric Dumazet
2012-07-05 10:02           ` David Miller
2012-07-05 10:32           ` Ming Lei
2012-07-05 10:41             ` Eric Dumazet
2012-07-05 14:01               ` Ming Lei
2012-07-05 14:28                 ` Eric Dumazet
2012-07-05 14:56                 ` Eric Dumazet
2012-07-06  0:45                   ` Ming Lei
2012-07-06  4:58                     ` Eric Dumazet
2012-07-06  5:16                       ` Eric Dumazet
2012-07-09  5:13                         ` Ming Lei
2012-07-09 13:23           ` Ming Lei
2012-07-09 13:54             ` Eric Dumazet
     [not found]               ` <CACVXFVNdiwVn1Mo--N4N0HdYrEJizExtd_cppT4tS=mjog2PKw@mail.gmail.com>
     [not found]                 ` <1341895143.3265.4049.camel@edumazet-glaptop>
2012-07-10  7:22                   ` Ming Lei
2012-07-10  8:28                     ` Eric Dumazet
2012-07-10 13:37                       ` Ming Lei
2012-07-10 14:02                         ` Eric Dumazet
2012-07-10 14:22                           ` Ming Lei
2012-07-10 14:45                             ` Eric Dumazet

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