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Add scheduling to ptpconfig docs
Add ptpSchedulingPolicy and ptpSchedulingPriority sections to ptpconfig documentation. updates to document new features delivered to fix BZ2016216
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‎modules/cnf-about-ptp-and-clock-synchronization.adoc

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// Module included in the following assemblies:
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//
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// * networking/configuring-ptp.adoc
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// * networking/using-ptp.adoc
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[id="cnf-about-ptp-and-clock-synchronization_{context}"]
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= About PTP and clock synchronization error events

‎modules/cnf-about-ptp-fast-event-notifications-framework.adoc

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// Module included in the following assemblies:
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//
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// * networking/configuring-ptp.adoc
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// * networking/using-ptp.adoc
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[id="cnf-about-ptp-fast-event-notifications-framework_{context}"]
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= About the PTP fast event notifications framework

‎modules/cnf-configuring-fifo-priority-scheduling-for-ptp.adoc

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// Module included in the following assemblies:
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//
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// * networking/using-ptp.adoc
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[id="cnf-configuring-fifo-priority-scheduling-for-ptp_{context}"]
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= Configuring FIFO priority scheduling for PTP hardware
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In telco or other deployment configurations that require low latency performance, PTP daemon threads run in a constrained CPU footprint alongside the rest of the infrastructure components. By default, PTP threads run with the `SCHED_OTHER` policy. Under high load, these threads might not get the scheduling latency they require for error-free operation.
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To mitigate against potential scheduling latency errors, you can configure the PTP Operator `linuxptp` services to allow threads to run with a `SCHED_FIFO` policy. If `SCHED_FIFO` is set for a `PtpConfig` CR, then `ptp4l` and `phc2sys` will run in the parent container under `chrt` with a priority set by the `ptpSchedulingPriority` field of the `PtpConfig` CR.
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[NOTE]
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====
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Setting `ptpSchedulingPolicy` is optional, and is only required if you are experiencing latency errors.
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====
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.Procedure
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. Edit the `PtpConfig` CR profile:
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[source,terminal]
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----
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$ oc edit PtpConfig -n openshift-ptp
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----
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. Change the `ptpSchedulingPolicy` and `ptpSchedulingPriority` fields:
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[source,yaml]
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----
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apiVersion: ptp.openshift.io/v1
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kind: PtpConfig
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metadata:
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name: <ptp_config_name>
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namespace: openshift-ptp
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...
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spec:
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profile:
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- name: "profile1"
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...
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ptpSchedulingPolicy: SCHED_FIFO <1>
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ptpSchedulingPriority: 65 <2>
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----
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<1> Scheduling policy for `ptp4l` and `phc2sys` processes. Use `SCHED_FIFO` on systems that support FIFO scheduling.
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<2> Required. Sets the integer value 1-65 used to configure FIFO priority for `ptp4l` and `phc2sys` processes.
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. Save and exit to apply the changes to the `PtpConfig` CR.
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.Verification
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. Get the name of the `linuxptp-daemon` pod and corresponding node where the `PtpConfig` CR has been applied:
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[source,terminal]
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----
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$ oc get pods -n openshift-ptp -o wide
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----
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.Example output
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[source,terminal]
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----
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NAME READY STATUS RESTARTS AGE IP NODE
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linuxptp-daemon-gmv2n 3/3 Running 0 1d17h 10.1.196.24 compute-0.example.com
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linuxptp-daemon-lgm55 3/3 Running 0 1d17h 10.1.196.25 compute-1.example.com
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ptp-operator-3r4dcvf7f4-zndk7 1/1 Running 0 1d7h 10.129.0.61 control-plane-1.example.com
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----
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. Check that the `ptp4l` process is running with the updated `chrt` FIFO priority:
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[source,terminal]
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----
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$ oc -n openshift-ptp logs linuxptp-daemon-lgm55 -c linuxptp-daemon-container|grep chrt
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----
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.Example output
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[source,terminal]
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----
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I1216 19:24:57.091872 1600715 daemon.go:285] /bin/chrt -f 65 /usr/sbin/ptp4l -f /var/run/ptp4l.0.config -2 --summary_interval -4 -m
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----
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‎modules/cnf-configuring-the-ptp-fast-event-publisher.adoc

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// Module included in the following assemblies:
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//
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// * networking/configuring-ptp.adoc
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// * networking/using-ptp.adoc
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[id="cnf-configuring-the-ptp-fast-event-publisher_{context}"]
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= Configuring the PTP fast event notifications publisher

‎modules/cnf-fast-event-notifications-api-refererence.adoc

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// Module included in the following assemblies:
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//
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// * networking/configuring-ptp.adoc
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// * networking/using-ptp.adoc
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[id="cnf-fast-event-notifications-api-refererence_{context}"]
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= PTP fast event notifications REST API reference

‎modules/cnf-installing-amq-interconnect-messaging-bus.adoc

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// Module included in the following assemblies:
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//
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// * networking/configuring-ptp.adoc
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// * networking/using-ptp.adoc
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[id="cnf-installing-amq-interconnect-messaging-bus_{context}"]
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= Installing the AMQ messaging bus

‎modules/cnf-monitoring-fast-events-metrics-using-cli.adoc

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// Module included in the following assemblies:
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//
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// * networking/configuring-ptp.adoc
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// * networking/using-ptp.adoc
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[id="cnf-monitoring-fast-events-metrics-using-cli_{context}"]
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= Monitoring PTP fast event metrics using the CLI

‎modules/cnf-ptp-fast-event-metrics-in-prometheus.adoc

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// Module included in the following assemblies:
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//
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// * networking/configuring-ptp.adoc
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// * networking/using-ptp.adoc
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[id="cnf-fast-event-metrics-in-prometheus_{context}"]
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= Monitoring PTP fast event metrics in the web console

‎modules/cnf-troubleshooting-common-ptp-operator-issues.adoc

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// Module included in the following assemblies:
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//
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// * networking/configuring-ptp.adoc
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// * networking/using-ptp.adoc
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[id="cnf-troubleshooting-common-ptp-operator-issues_{context}"]
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= Troubleshooting common PTP Operator issues

‎modules/nw-ptp-configuring-linuxptp-services-as-boundary-clock.adoc

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// Module included in the following assemblies:
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//
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// * networking/multiple_networks/configuring-ptp.adoc
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// * networking/using-ptp.adoc
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[id="configuring-linuxptp-services-as-boundary-clock_{context}"]
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= Configuring linuxptp services as boundary clock
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userDescription ;
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timeSource 0xA0
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phc2sysOpts: "-a -r" <9>
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recommend: <10>
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- profile: "profile1" <11>
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priority: 10 <12>
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match: <13>
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- nodeLabel: "node-role.kubernetes.io/worker" <14>
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nodeName: "compute-0.example.com" <15>
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ptpSchedulingPolicy: SCHED_OTHER <10>
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ptpSchedulingPriority: 65 <11>
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recommend: <12>
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- profile: "profile1" <13>
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priority: 10 <14>
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match: <15>
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- nodeLabel: "node-role.kubernetes.io/worker" <16>
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nodeName: "compute-0.example.com" <17>
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----
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<1> The name of the `PtpConfig` CR.
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<2> Specify an array of one or more `profile` objects.
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<7> The interface name to synchronize from.
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<8> The interface to synchronize devices connected to the interface.
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<9> Specify system config options for the `phc2sys` service, for example `-a -r`. If this field is empty the PTP Operator does not start the `phc2sys` service.
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<10> Specify an array of one or more `recommend` objects which define rules on how the `profile` should be applied to nodes.
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<11> Specify the `profile` object name defined in the `profile` section.
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<12> Specify the `priority` with an integer value between `0` and `99`. A larger number gets lower priority, so a priority of `99` is lower than a priority of `10`. If a node can be matched with multiple profiles according to rules defined in the `match` field, the profile with the higher priority is applied to that node.
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<13> Specify `match` rules with `nodeLabel` or `nodeName`.
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<14> Specify `nodeLabel` with the `key` of `node.Labels` from the node object.
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<15> Specify `nodeName` with `node.Name` from the node object.
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<10> Scheduling policy for ptp4l and phc2sys processes. Default value is `SCHED_OTHER`. Use `SCHED_FIFO` on systems that support FIFO scheduling.
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<11> Integer value from 1-65 used to set FIFO priority for `ptp4l` and `phc2sys` processes. Required if `SCHED_FIFO` is set for `ptpSchedulingPolicy`.
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<12> Specify an array of one or more `recommend` objects that define rules on how the `profile` should be applied to nodes.
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<13> Specify the `profile` object name defined in the `profile` section.
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<14> Specify the `priority` with an integer value between `0` and `99`. A larger number gets lower priority, so a priority of `99` is lower than a priority of `10`. If a node can be matched with multiple profiles according to rules defined in the `match` field, the profile with the higher priority is applied to that node.
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<15> Specify `match` rules with `nodeLabel` or `nodeName`.
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<16> Specify `nodeLabel` with the `key` of `node.Labels` from the node object.
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<17> Specify `nodeName` with `node.Name` from the node object.
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. Create the CR by running the following command:
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.Verification steps
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. Check that the `PtpConfig` profile is applied to node.
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. Check that the `PtpConfig` profile is applied to the node.
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.. Get the list of pods in the `openshift-ptp` namespace by running the following command:
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