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From: Fabrice Bellard <fabrice@bellard.org>
To: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] Can you commit the pcnet patch ?
Date: Thu, 21 Jul 2005 23:14:32 +0200	[thread overview]
Message-ID: <42E01038.8030202@bellard.org> (raw)
In-Reply-To: <200507211419.51421.paul@codesourcery.com>

Paul Brook wrote:
> On Thursday 21 July 2005 08:29, Lars Munch wrote:
> 
>>On Wed, Jul 20, 2005 at 12:32:10PM +0200, Ludovic Drolez wrote:
>>
>>>Hi !
>>>
>>>I've tried the latest AMD pcnet patch (made by Antony T Curtis) with qemu
>>>0.7 because I was tired of the sloooww PXE booting of my QEMU. For
>>>exemple, to load a linux kernel + initrd over TFTP, it takes 4m30s with a
>>>ne2000, and 1m35s with the PCNET card.
>>
>>Does anyone know why pcnet is so much faster than ne2000? is it easier
>>to emulate? or is there room for improvements on the ne2000?
> 
> 
> Probably because it's a DMA capable controller. IIRC the ne2k is pio based, so 
> has to shuffle the data through an IO port one byte at a time.

I don't think that the switch to DMA can explain a factor of 3. Another 
possibility is that there is a bug in the ne2000 code. It could be 
interesting to check the send and receive latencies by adding traces in 
the ne2000 code...

Fabrice.

      parent reply	other threads:[~2005-07-21 21:24 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-07-20 10:32 [Qemu-devel] Can you commit the pcnet patch ? Ludovic Drolez
2005-07-20 12:37 ` Paul Brook
2005-07-20 12:48   ` Christian MICHON
2005-07-21 15:32     ` Ludovic Drolez
2005-07-20 12:56   ` Ludovic Drolez
2005-07-20 14:26     ` Christian MICHON
2005-07-20 14:45       ` Christian MICHON
2005-07-20 15:19         ` Christian MICHON
2005-07-20 15:29           ` Paul Brook
2005-07-20 15:37         ` Filip Navara
2005-07-21 11:33           ` Christian MICHON
2005-07-21 16:43             ` Filip Navara
2005-07-21 20:21               ` Filip Navara
2005-07-21 20:54                 ` Christian MICHON
2005-07-21  7:29 ` Lars Munch
2005-07-21 13:19   ` Paul Brook
2005-07-21 13:49     ` Christian MICHON
2005-07-21 19:10       ` Antony T Curtis
2005-07-21 21:14     ` Fabrice Bellard [this message]

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