On Tue, Jan 18, 2011 at 11:41:22AM -0800, Rick Jones wrote: > >So it won't be all that simple to implement well, and before we try, > >I'd like to know whether there are applications that are helped > >by it. For example, we could try to measure latency at various > >pps and see whether the backpressure helps. netperf has -b, -w > >flags which might help these measurements. > > Those options are enabled when one adds --enable-burst to the > pre-compilation ./configure of netperf (one doesn't have to > recompile netserver). However, if one is also looking at latency > statistics via the -j option in the top-of-trunk, or simply at the > histogram with --enable-histogram on the ./configure and a verbosity > level of 2 (global -v 2) then one wants the very top of trunk > netperf from: > > http://www.netperf.org/svn/netperf2/trunk > > to get the recently added support for accurate (netperf level) RTT > measuremnts on burst-mode request/response tests. > > happy benchmarking, > > rick jones > > PS - the enhanced latency statistics from -j are only available in > the "omni" version of the TCP_RR test. To get that add a > --enable-omni to the ./configure - and in this case both netperf and > netserver have to be recompiled. Is this TCP only? I would love to get latency data from UDP as well. > For very basic output one can > peruse the output of: > > src/netperf -t omni -- -O /? > > and then pick those outputs of interest and put them into an output > selection file which one then passes to either (test-specific) -o, > -O or -k to get CVS, "Human" or keyval output respectively. E.G. > > raj@tardy:~/netperf2_trunk$ cat foo > THROUGHPUT,THROUGHPUT_UNITS > RT_LATENCY,MIN_LATENCY,MEAN_LATENCY,MAX_LATENCY > P50_LATENCY,P90_LATENCY,P99_LATENCY,STDDEV_LATENCY > > when foo is passed to -o one will get those all on one line of CSV. > To -O one gets three lines of more netperf-classic-like "human" > readable output, and when one passes that to -k one gets a string of > keyval output a la: > > raj@tardy:~/netperf2_trunk$ src/netperf -t omni -j -v 2 -- -r 1 -d rr -k foo > OMNI TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to localhost > (127.0.0.1) port 0 AF_INET : histogram > THROUGHPUT=29454.12 > THROUGHPUT_UNITS=Trans/s > RT_LATENCY=33.951 > MIN_LATENCY=19 > MEAN_LATENCY=32.00 > MAX_LATENCY=126 > P50_LATENCY=32 > P90_LATENCY=38 > P99_LATENCY=41 > STDDEV_LATENCY=5.46 > > Histogram of request/response times > UNIT_USEC : 0: 0: 0: 0: 0: 0: 0: 0: 0: 0 > TEN_USEC : 0: 3553: 45244: 237790: 7859: 86: 10: 3: 0: 0 > HUNDRED_USEC : 0: 2: 0: 0: 0: 0: 0: 0: 0: 0 > UNIT_MSEC : 0: 0: 0: 0: 0: 0: 0: 0: 0: 0 > TEN_MSEC : 0: 0: 0: 0: 0: 0: 0: 0: 0: 0 > HUNDRED_MSEC : 0: 0: 0: 0: 0: 0: 0: 0: 0: 0 > UNIT_SEC : 0: 0: 0: 0: 0: 0: 0: 0: 0: 0 > TEN_SEC : 0: 0: 0: 0: 0: 0: 0: 0: 0: 0 > >100_SECS: 0 > HIST_TOTAL: 294547 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
