1 .. This work is licensed under a Creative Commons Attribution 4.0 International License.
2 .. http://creativecommons.org/licenses/by/4.0
4 =============================================
5 Low Latency Feature Configuration Description
6 =============================================
10 In KVM4NFV project, we focus on the KVM hypervisor to enhance it for NFV, by
11 looking at the following areas initially
13 * Minimal Interrupt latency variation for data plane VNFs:
14 * Minimal Timing Variation for Timing correctness of real-time VNFs
15 * Minimal packet latency variation for data-plane VNFs
16 * Inter-VM communication,
19 Configuration of Cyclictest
20 ---------------------------
22 Cyclictest measures Latency of response to a stimulus. Achieving low latency
23 with the KVM4NFV project requires setting up a special test environment.
24 This environment includes the BIOS settings, kernel configuration, kernel
25 parameters and the run-time environment.
27 * For more information regarding the test environment, please visit
28 https://wiki.opnfv.org/display/kvm/KVM4NFV+Test++Environment
29 https://wiki.opnfv.org/display/kvm/Nfv-kvm-tuning
31 Pre-configuration activities
32 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
34 Intel POD10 is currently used as OPNFV-KVM4NFV test environment. The rpm
35 packages from the latest build are downloaded onto Intel-Pod10 jump server
36 from artifact repository. Yardstick running in a ubuntu docker container
37 on Intel Pod10-jump server will configure the host(intel pod10 node1/node2
38 based on job type), the guest and triggers the cyclictest on the guest using
39 below sample yaml file.
57 .. figure:: images/idle-idle-test.png
64 For [CPU/Memory/IO]Stress-IDLE tests,
70 - "stress_daily.sh" [cpustress/memory/io]
78 .. figure:: images/stress-idle-test.png
79 :name: stress-idle-test
83 The following scripts are used for configuring host and guest to create a
84 special test environment and achieve low latency.
86 Note: host-setup0.sh, host-setup1.sh and host-run-qemu.sh are run on the host,
87 followed by guest-setup0.sh and guest-setup1.sh scripts on the guest VM.
89 **host-setup0.sh**: Running this script will install the latest kernel rpm
90 on host and will make necessary changes as following to create special test
93 * Isolates CPUs from the general scheduler
94 * Stops timer ticks on isolated CPUs whenever possible
95 * Stops RCU callbacks on isolated CPUs
96 * Enables intel iommu driver and disables DMA translation for devices
97 * Sets HugeTLB pages to 1GB
98 * Disables machine check
99 * Disables clocksource verification at runtime
101 **host-setup1.sh**: Running this script will make the following test
104 * Disabling watchdogs to reduce overhead
105 * Disabling RT throttling
106 * Reroute interrupts bound to isolated CPUs to CPU 0
107 * Change the iptable so that we can ssh to the guest remotely
109 **stress_daily.sh**: Scripts gets triggered only for stress-idle tests. Running this script
110 make the following environment changes.
112 * Triggers stress_script.sh, which runs the stress command with necessary options
113 * CPU,Memory or IO stress can be applied based on the test type
114 * Applying stress only on the Host is handled in D-Release
115 * For Idle-Idle test the stress script is not triggered
116 * Stress is applied only on the free cores to prevent load on qemu process
119 - On Numa Node 1: 22,23 cores are allocated for QEMU process
120 - 24-43 are used for applying stress
122 **host-run-qemu.sh**: Running this script will launch a guest vm on the host.
123 Note: download guest disk image from artifactory.
125 **guest-setup0.sh**: Running this scrcipt on the guest vm will install the
126 latest build kernel rpm, cyclictest and make the following configuration on
129 * Isolates CPUs from the general scheduler
130 * Stops timer ticks on isolated CPUs whenever possible
131 * Uses polling idle loop to improve performance
132 * Disables clocksource verification at runtime
134 **guest-setup1.sh**: Running this script on guest vm will do the following
137 * Disable watchdogs to reduce overhead
138 * Routes device interrupts to non-RT CPU
139 * Disables RT throttling
141 Hardware configuration
142 ~~~~~~~~~~~~~~~~~~~~~~
144 Currently Intel POD10 is used as test environment for kvm4nfv to execute
145 cyclictest. As part of this test environment Intel pod10-jump is configured as
146 jenkins slave and all the latest build artifacts are downloaded on to it.
148 * For more information regarding hardware configuration, please visit
149 https://wiki.opnfv.org/display/pharos/Intel+Pod10
150 https://build.opnfv.org/ci/computer/intel-pod10/
151 http://artifacts.opnfv.org/octopus/brahmaputra/docs/octopus_docs/opnfv-jenkins-slave-connection.html