NFS Performance

[Steven Johnson]

Till Straumann wrote:

> Joel Sherrill wrote:
>
>> Steven Johnson wrote:
>>
>>> Joel, Thanks for the pointer. setvbuf worked like a treat.  So, we
>>> don't
>>> have to hack stdio.h, thanks for the suggestion.
>>>
>>>   
>>
>>
>> I'm glad setvbuf worked.  It is always nice to not hack at a standard
>> include file.
>>
>>> Following are some benchmarks we got with different block sizes. 
>>> MPC862
>>> Processor (PowerPC) at 100Mhz, with 50Mhz SDRAM main memory and using
>>> the FEC (Fast Ethernet Controller @ 100Mbit/s, full duplex), its a
>>> custom design and doesn't use a standard BSP, but isn't dissimilar to
>>> the standard MPC862 BSP:
>>>
>>> Times to transfer the 7.4M test file timed using ticks_since_boot, (1
>>> tick is 10ms on our target):
>>> Buffer Size @ Ticks to transfer = ~Mbit/s
>>>
>>> 256 @ 4265  = ~1.4Mbit/s
>>> 512 @ 2221  = ~2.7Mbit/s
>>> 1024 @ 1239 = ~4.8Mbit/s
>>> 2048 @ 712 = ~8.4Mbit/s
>>> 4096 @ 439 = ~13.7Mbit/s
>>> 8192 @ 298 = ~20.2Mbit/s
>>> 16384 @ 299 =~20.2Mbit/s
>>> 32768 @ 298 =~20.2Mbit/s
>>>   
>>
>>
>>
>> You don't mention what the NFS server is and how it does from
>> a similar host.
>
The NFS Server is a Linux Box (Linux version 2.4.21-0.13mdk, Mandrake
Linux 9.1)

It is a 2.7Ghz P4 with 1GB of ram.

Ethernet controller: Broadcom Corporation BCM4401 100Base-T.

>From a similarly spec'd Linux box, between the machines, we can sustain
about 88Mbit/s NFS transfer rate, with a single file transfer.  Not
unsurprisingly, given the sophisticated caching, etc in linux setvbuf
has no effect on the speed of NFS on the linux box.  I don't know if the
20Mbit/s from our rtems box is a limit on our MPC862's processing
performance or the performance of the FEC, or deficiencies in the NFS
stack.  Probably all of the above.  Yet given the relative level's of
complexity, 20Mbit/s is very respectable in my opinion.  It is certainly
fast enough for our application's needs.

> done - I incorporated the comments I posted yesterday into the README.
> Also, I added a test code.
>
> -- T. 

That's great.  I'll throw up a Wiki topic on it soon.

Steven J