[netperf-talk] Thin streams in Netperf

[Rick Jones]

Jon Pedersen wrote:
> Hi!
> 
> I was wondering if it is possible to send thin streams with Netperf?
> Generally , it looks like Netperf tries to send as much data as
> possible at once, but I would like it to slow down a bit resulting in
> thinner streams.

Assuming I've understood what you meant by a thinner stream, that would be via 
the --enable-intervals in the configure script, which will enable two global 
commandline options -  -w for the interburst interfal, and -b for the burst size.

I just checked-in some changes yesterday that should allow --enable-intervals 
configuration to compile. :)

Standard --enable-intervals uses the interval timer, which sets the effective 
granularity of the time given in the -w option.  Often as not that is 10 ms, on 
some platforms it may be as low as 1 ms.

If you are willing to blow the netperf-side CPU utilization out of the water, 
also yesterday :) I checked-in some changes to add a --enable-spin which causes 
the interval timer to be replaced by a "sit and spin" approach, calling 
gettimeofday() or gethrtime() until the desired interburst interval is reached.

Related to this was a change to add the ability to specify time in the -w option 
in more than just milliseconds.  Much as with the arguments to -s, -S, -m etc a 
"timespec" has an optional suffix - 'm' (eg "10m") means the units are 
milliseconds, 'u' means microseconds and 's' means seconds (I've not taken it as 
far as nanoseconds - seems a _bit_ premature).

So, fire-up your friendly neighborhood subversion client and grab the 
top-of-trunk bits from http://www.netperf.org/svn/netperf2/trunk

happy benchmarking,

rick jones