Performance Testing¶
Performance subtests¶
block¶
- iozone (linux)
- iozone (windows) (iozone has its own result analysis module)
- iometer (windows) (not push upstream)
- ffsb (linux)
- qemu_iotests (host)
- fio (linux)
Environment setup¶
Autotest already supports prepare environment for performance testing, guest/host need to be reboot for some configuration. setup script
Autotest supports to numa pining. Assign “numanode=-1” in tests.cfg, then vcpu threads/vhost_net threads/VM memory will be pined to last numa node. If you want to pin other processes to numa node, you can use numctl and taskset.
memory:
$ numactl -m $n $cmdline
cpu:
$ taskset $node_mask $thread_id
The following content is manual guide.
1.First level pinning would be to use numa pinning when starting the guest.
e.g. $ numactl -c 1 -m 1 qemu-kvm -smp 2 -m 4G <> (pinning guest memory and cpus to numa-node 1)
2.For a single instance test, it would suggest trying a one to one mapping of vcpu to pyhsical core.
e.g.
get guest vcpu threads id
$ taskset -p 40 $vcpus1 #(pinning vcpu1 thread to pyshical cpu #6 )
$ taskset -p 80 $vcpus2 #(pinning vcpu2 thread to physical cpu #7 )
3.To pin vhost on host. get vhost PID and then use taskset to pin it on the same soket.
e.g
$ taskset -p 20 $vhost #(pinning vcpu2 thread to physical cpu #5 )
4.In guest,pin the IRQ to one core and the netperf to another.
1) make sure irqbalance is off - `$ service irqbalance stop`
2) find the interrupts - `$ cat /proc/interrupts`
3) find the affinity mask for the interrupt(s) - `$ cat /proc/irq/<irq#>/smp_affinity`
4) change the value to match the proper core.make sure the vlaue is cpu mask.
e.g. pin the IRQ to first core.
$ echo 01>/proc/irq/$virti0-input/smp_affinity
$ echo 01>/proc/irq/$virti0-output/smp_affinity
5)pin the netserver to another core.
e.g.
$ taskset -p 02 netserver
5.For host to guest scenario. to get maximum performance. make sure to run netperf on different cores on the same numa node as the guest.
e.g.
$ numactl -m 1 netperf -T 4 (pinning netperf to physical cpu #4)
Execute testing¶
- Submit jobs in Autotest server, only execute netperf.guset_exhost for three times.
tests.cfg
:
only netperf.guest_exhost
variants:
- repeat1:
- repeat2:
- repeat3:
# vbr0 has a static ip: 192.168.100.16
bridge=vbr0
# virbr0 is created by libvirtd, guest nic2 get ip by dhcp
bridge_nic2 = virbr0
# guest nic1 static ip
ip_nic1 = 192.168.100.21
# external host static ip:
client = 192.168.100.15
Result files:
$ cd /usr/local/autotest/results/8-debug_user/192.168.122.1/
$ find .|grep RHS
kvm.repeat1.r61.virtio_blk.smp2.virtio_net.RHEL.6.1.x86_64.netperf.exhost_guest/results/netperf-result.RHS
kvm.repeat2.r61.virtio_blk.smp2.virtio_net.RHEL.6.1.x86_64.netperf.exhost_guest/results/netperf-result.RHS
kvm.repeat3.r61.virtio_blk.smp2.virtio_net.RHEL.6.1.x86_64.netperf.exhost_guest/results/netperf-result.RHS
- Submit same job in another env (different packages) with same configuration
Result files:
$ cd /usr/local/autotest/results/9-debug_user/192.168.122.1/
$ find .|grep RHS
kvm.repeat1.r61.virtio_blk.smp2.virtio_net.RHEL.6.1.x86_64.netperf.exhost_guest/results/netperf-result.RHS
kvm.repeat2.r61.virtio_blk.smp2.virtio_net.RHEL.6.1.x86_64.netperf.exhost_guest/results/netperf-result.RHS
kvm.repeat3.r61.virtio_blk.smp2.virtio_net.RHEL.6.1.x86_64.netperf.exhost_guest/results/netperf-result.RHS
Analysis result¶
Config file: perf.conf
[ntttcp]
result_file_pattern = .*.RHS
ignore_col = 1
avg_update =
[netperf]
result_file_pattern = .*.RHS
ignore_col = 2
avg_update = 4,2,3|14,5,12|15,6,13
[iozone]
result_file_pattern =
Execute regression.py to compare two results:
login autotest server
$ cd /usr/local/autotest/client/tools
$ python regression.py netperf /usr/local/autotest/results/8-debug_user/192.168.122.1/ /usr/local/autotest/results/9-debug_user/192.168.122.1/
T-test:
- scipy: http://www.scipy.org/
- t-test: http://en.wikipedia.org/wiki/Student’s_t-test
- Two python modules (scipy and numpy) are needed.
- Script to install numpy/scipy on rhel6 automatically: https://github.com/kongove/misc/blob/master/scripts/install-numpy-scipy.sh
Unpaired T-test is used to compare two samples, user can check p-value to know if regression bug exists. If the difference of two samples is considered to be not statistically significant(p <= 0.05), it will add a ‘+’ or ‘-‘ before p-value. (‘+’: avg_sample1 < avg_sample2, ‘-‘: avg_sample1 > avg_sample2)
- - only over 95% confidence results will be added “+/-” in “Significance” part.
- + for cpu-usage means regression, “+” for throughput means improvement.”
Regression results¶
- netperf.exhost_guest.html
- fio.html
- Every Avg line represents the average value based on $n repetitions of the same test, and the following SD line represents the Standard Deviation between the $n repetitions.
- The Standard deviation is displayed as a percentage of the average.
- The significance of the differences between the two averages is calculated using unpaired T-test that takes into account the SD of the averages.
- The paired t-test is computed for the averages of same category.
- only over 95% confidence results will be added “+/-” in “Significance” part. “+” for cpu-usage means regression, “+” for throughput means improvement.
Highlight HTML result
- green/red –> good/bad
- Significance is larger than 0.95 –> green
- dark green/red –> important (eg: cpu)
- light green/red –> other
- test time
- version (only when diff)
- other: repeat time, title
- user light green/red to highlight small (< %5) DIFF
- highlight Significance with same color in one raw
- add doc link to result file, and describe color in doc
netperf.avg.html - Raw data that the averages are based on.