bad NFS/UDP performance

[Danny Braniss]

> 
> On Sat, 4 Oct 2008, Danny Braniss wrote:
> 
> > at the moment, the best I can do is run it on a different hardware that has 
> > if_em, the results are in
> > 	ftp://ftp.cs.huji.ac.il/users/danny/lock.prof/7.1-1000.em the 
> > benchmark ran better with the Intel NIC, averaged UDP 54MB/s, TCP 53MB/s (I 
> > get the same numbers with an older kernel).
> 
> Dear Danny:
> 
> Unfortunately, I was left slightly unclear on the comparison you are making 
> above.  Could you confirm whether or not, with if_em, you see a performance 
> regression using UDP NFS between 7.0-RELEASE and the most recent 7.1-STABLE, 
> and if you do, whether or not the RLOCK->WLOCK change has any effect on 
> performance?  It would be nice to know on the same hardware but at least with 
> different hardware we get a sense of whether or not this might affect other 
> systems or whether it's limited to a narrower set of configurations.
> 
> Thanks,

	7.1-1000.em		vanilla 7.1	    1 x Intel Core Duo
	7.1-1000.x2200.em	vanilla 7.1	    2 x Dual-Core AMD Opteron
	7.0-1000.x2200.em	7.0 + RLOCK->WLOCK

the plot thickens.
I put an em card in, and the throughput is almost the same than with the bge.

all the tests were done on the same host, a Sun x2200/amd/2cpux2core
except for the one over the weekend that is a intel Core Duo, and not the same
if_em card, sorry about that but one has PCI X, the other PCI Express :-(.

what is becoming obvious is that NFS/UDP is very temperamental/sensitive :-)

danny