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diff --git a/docs/configurationguide/low-latency.feature.configuration.description.rst b/docs/configurationguide/low-latency.feature.configuration.description.rst new file mode 100644 index 000000000..bb2bbd1ba --- /dev/null +++ b/docs/configurationguide/low-latency.feature.configuration.description.rst @@ -0,0 +1,93 @@ +.. This work is licensed under a Creative Commons Attribution 4.0 International License. +.. http://creativecommons.org/licenses/by/4.0 + +Introduction +============ + +In KVM4NFV project, we focus on the KVM hypervisor to enhance it for NFV, by +looking at the following areas initially + +* Minimal Interrupt latency variation for data plane VNFs: + * Minimal Timing Variation for Timing correctness of real-time VNFs + * Minimal packet latency variation for data-plane VNFs +* Inter-VM communication, +* Fast live migration + +Configuration of Cyclictest +=========================== + +Cyclictest measures Latency of response to a stimulus. Achieving low latency +with the KVM4NFV project requires setting up a special test environment. +This environment includes the BIOS settings, kernel configuration, kernel +parameters and the run-time environment. + +* For more information regarding the test environment, please visit + https://wiki.opnfv.org/display/kvm/KVM4NFV+Test++Environment + https://wiki.opnfv.org/display/kvm/Nfv-kvm-tuning + +Pre-configuration activities +---------------------------- + +Intel POD1 is currently used as OPNFV-KVM4NFV test environment. The latest +build packages are downloaded onto Intel Pod1-jump server from artifact +repository. Yardstick running in a ubuntu docker container on Intel Pod1-jump +server will trigger the cyclictest. + +Running cyclictest through Yardstick will Configure the host(Pod1-node1), the +guest, executes cyclictest on the guest. + +The following scripts are used for configuring host and guest to create a +special test environment and achieve low latency. + +**host-setup0.sh**: On running this script will install latest kernel rpm +on host and will make necessary changes as following to create special test +environment + + * Isolates CPUs from the general scheduler + * Stops timer ticks on isolated CPUs whenever possible + * Stops RCU callbacks on isolated CPUs + * Enables intel iommu driver and disables DMA translation for devices + * Sets HugeTLB pages to 1GB + * Disables machine check + * Disables clocksource verification at runtime + +**host-setup1.sh**: On running this script will make following test +environment changes + + * Disabling watchdogs to reduce overhead + * Disabling RT throttling + * Reroute interrupts bound to isolated CPUs to CPU 0 + * Change the iptable so that we can ssh to the guest remotely + +**host-run-qemu.sh**: On running this script will launch a guest vm on host. + Note: download guest disk image from artifactory + +**guest-setup0.sh**: On running this scrcipt on guest vm will install the +latest build kernel rpm, cyclictest and makes following configuration on +guest vm. + + * Isolates CPUs from the general scheduler + * Stops timer ticks on isolated CPUs whenever possible + * Uses polling idle loop to improve performance + * Disables clocksource verification at runtime + +**guest-setup1.sh**: On running this script on guest vm will make following +configurations + + * Disable watchdogs to reduce overhead + * Routes device interrupts to non-RT CPU + * Disables RT throttling + +Hardware configuration +---------------------- + +Currently Intel POD1 is used as test environment for kvmfornfv to execute +cyclictest. As part of this test environment Intel pod1-jump is configured as +jenkins slave and all the latest build artifacts are downloaded on to it. +Intel pod1-node1 is the host on which a guest vm will be launched as a part of +running cylictest through yardstick. + +* For more information regarding hardware configuration, please visit + https://wiki.opnfv.org/display/pharos/Intel+Pod1 + https://build.opnfv.org/ci/computer/intel-pod1/ + http://artifacts.opnfv.org/octopus/brahmaputra/docs/octopus_docs/opnfv-jenkins-slave-connection.html |