[ Trimmed Eric from CC list as vger was complaining that it is too long ] 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: Hi, I have constructed a test where I run an un-paced UDP_STREAM test in one guest and a paced omni rr test in another guest at the same time. Breifly I get the following results from the omni test.. 1. Omni test only: MEAN_LATENCY=272.00 2. Omni and stream test: MEAN_LATENCY=3423.00 3. cpu and net_cls group: MEAN_LATENCY=493.00 As per 2 plus cgoups are created for each guest and guest tasks added to the groups 4. 100Mbit/s class: MEAN_LATENCY=273.00 As per 3 plus the net_cls groups each have a 100MBit/s HTB class 5. cpu.shares=128: MEAN_LATENCY=652.00 As per 4 plus the cpu groups have cpu.shares set to 128 6. Busy CPUS: MEAN_LATENCY=15126.00 As per 5 but the CPUs are made busy using a simple shell while loop There is a bit of noise in the results as the two netperf invocations aren't started at exactly the same moment For reference, my netperf invocations are: netperf -c -C -t UDP_STREAM -H 172.17.60.216 -l 12 netperf.omni -p 12866 -D -c -C -H 172.17.60.216 -t omni -j -v 2 -- -r 1 -d rr -k foo -b 1 -w 200 -m 200 foo contains PROTOCOL THROUGHPUT,THROUGHPUT_UNITS LOCAL_SEND_THROUGHPUT LOCAL_RECV_THROUGHPUT REMOTE_SEND_THROUGHPUT REMOTE_RECV_THROUGHPUT RT_LATENCY,MIN_LATENCY,MEAN_LATENCY,MAX_LATENCY P50_LATENCY,P90_LATENCY,P99_LATENCY,STDDEV_LATENCY LOCAL_CPU_UTIL,REMOTE_CPU_UTIL _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
