[RFC] gianfar: low gigabit throughput

[Andy Fleming]

>>
>> I've tried to tune gianfar driver in various ways... and it gave
>> some positive results with this patch:
>> diff --git a/drivers/net/gianfar.h b/drivers/net/gianfar.h
>> index fd487be..b5943f9 100644
>> --- a/drivers/net/gianfar.h
>> +++ b/drivers/net/gianfar.h
>> @@ -123,8 +123,8 @@ extern const char gfar_driver_version[];
>> #define GFAR_10_TIME    25600
>>  #define DEFAULT_TX_COALESCE 1
>> -#define DEFAULT_TXCOUNT	16
>> -#define DEFAULT_TXTIME	21
>> +#define DEFAULT_TXCOUNT	80
>> +#define DEFAULT_TXTIME	105
>>  #define DEFAULT_RXTIME	21
>
> No ethtool coalescing tuning support for gianfar?-)

Yeah, there's coalescing tuning in gianfar.

Anton, those numbers aren't too surprising on a 400 MHz machine, I  
think.  But I'd be happy to see any analysis on performance  
bottlenecks in the driver.  And patches to fix those bottlenecks are  
even better!  :)

Andy