Re: rx dma count

On Monday 19 May 2003 12:47 pm, Bob Beers wrote:
> Hello list,
>
> I have been happily using the eepro100 driver, but recently
> discovered that a motherboard I am using has an "interesting"
> PCI feature: it allows only 3 dwords per dma rx burst.  And, not
> surprisingly, I have sub-optimal performance on this interface.
> I tried to set the rxdmacount  to try to force the driver to
> accomodate this limitation, but I didn't notice any difference in
> performance. I found this option by using the modinfo comand, but the
> description only says "int".  I haven't yet dug into the code, can
> someone tell me off hand, if this parameter affects the issue at
> hand, and what the appropriate value would be?
>
> Thanks,
> -Bob

ok, now I have looked at the code and I conducted a simple ftp
experiment sending a compressed 500k file several times.  
This table shows the results.

parm                           | thru-put e+06 bytes/sec 
rxdmacount     | txdmacount    | get           | put           | 
_______________|_______________|_______________|_______________| 
0              | 128           | 1.227         | 1.107         | 
0              | 3             | 1.220         | 1.114         | 
0              | 1             | 1.209         | 1.111         | 
128            | 128           | 1.223         | 1.092         | 
128            | 3             | 1.229         | 1.083         | 
3              | 3             | 1.225         | 1.110         | 
0              | 0             | 1.217         | 1.105         |


I don't see a significant effect.  Any hints?  

Is this list still active? I don't see _any_ responses in May. 

-- 
Bob Beers
Edge Access, Inc.