Skip to content

Commit d22e7b0

Browse files
josephdrichardaireilly
josephdrichard
authored and
aireilly
committed
Add scheduling to ptpconfig docs
Add ptpSchedulingPolicy and ptpSchedulingPriority sections to ptpconfig documentation. updates to document new features delivered to fix BZ2016216
1 parent e538318 commit d22e7b0

15 files changed

+128
-70
lines changed

‎modules/cnf-about-ptp-and-clock-synchronization.adoc‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
11
// Module included in the following assemblies:
22
//
3-
// * networking/configuring-ptp.adoc
3+
// * networking/using-ptp.adoc
44

55
[id="cnf-about-ptp-and-clock-synchronization_{context}"]
66
= About PTP and clock synchronization error events

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

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
11
// Module included in the following assemblies:
22
//
3-
// * networking/configuring-ptp.adoc
3+
// * networking/using-ptp.adoc
44

55
[id="cnf-about-ptp-fast-event-notifications-framework_{context}"]
66
= About the PTP fast event notifications framework

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

Lines changed: 79 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,79 @@
1+
// Module included in the following assemblies:
2+
//
3+
// * networking/using-ptp.adoc
4+
5+
[id="cnf-configuring-fifo-priority-scheduling-for-ptp_{context}"]
6+
= Configuring FIFO priority scheduling for PTP hardware
7+
8+
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.
9+
10+
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.
11+
12+
[NOTE]
13+
====
14+
Setting `ptpSchedulingPolicy` is optional, and is only required if you are experiencing latency errors.
15+
====
16+
17+
.Procedure
18+
19+
. Edit the `PtpConfig` CR profile:
20+
+
21+
[source,terminal]
22+
----
23+
$ oc edit PtpConfig -n openshift-ptp
24+
----
25+
26+
. Change the `ptpSchedulingPolicy` and `ptpSchedulingPriority` fields:
27+
+
28+
[source,yaml]
29+
----
30+
apiVersion: ptp.openshift.io/v1
31+
kind: PtpConfig
32+
metadata:
33+
name: <ptp_config_name>
34+
namespace: openshift-ptp
35+
...
36+
spec:
37+
profile:
38+
- name: "profile1"
39+
...
40+
ptpSchedulingPolicy: SCHED_FIFO <1>
41+
ptpSchedulingPriority: 65 <2>
42+
----
43+
<1> Scheduling policy for `ptp4l` and `phc2sys` processes. Use `SCHED_FIFO` on systems that support FIFO scheduling.
44+
<2> Required. Sets the integer value 1-65 used to configure FIFO priority for `ptp4l` and `phc2sys` processes.
45+
46+
. Save and exit to apply the changes to the `PtpConfig` CR.
47+
48+
.Verification
49+
50+
. Get the name of the `linuxptp-daemon` pod and corresponding node where the `PtpConfig` CR has been applied:
51+
+
52+
[source,terminal]
53+
----
54+
$ oc get pods -n openshift-ptp -o wide
55+
----
56+
+
57+
.Example output
58+
[source,terminal]
59+
----
60+
NAME READY STATUS RESTARTS AGE IP NODE
61+
linuxptp-daemon-gmv2n 3/3 Running 0 1d17h 10.1.196.24 compute-0.example.com
62+
linuxptp-daemon-lgm55 3/3 Running 0 1d17h 10.1.196.25 compute-1.example.com
63+
ptp-operator-3r4dcvf7f4-zndk7 1/1 Running 0 1d7h 10.129.0.61 control-plane-1.example.com
64+
----
65+
66+
. Check that the `ptp4l` process is running with the updated `chrt` FIFO priority:
67+
+
68+
[source,terminal]
69+
----
70+
$ oc -n openshift-ptp logs linuxptp-daemon-lgm55 -c linuxptp-daemon-container|grep chrt
71+
----
72+
+
73+
.Example output
74+
[source,terminal]
75+
----
76+
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
77+
----
78+
79+

‎modules/cnf-configuring-the-ptp-fast-event-publisher.adoc‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
11
// Module included in the following assemblies:
22
//
3-
// * networking/configuring-ptp.adoc
3+
// * networking/using-ptp.adoc
44

55
[id="cnf-configuring-the-ptp-fast-event-publisher_{context}"]
66
= Configuring the PTP fast event notifications publisher

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

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
11
// Module included in the following assemblies:
22
//
3-
// * networking/configuring-ptp.adoc
3+
// * networking/using-ptp.adoc
44

55
[id="cnf-fast-event-notifications-api-refererence_{context}"]
66
= PTP fast event notifications REST API reference

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

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
11
// Module included in the following assemblies:
22
//
3-
// * networking/configuring-ptp.adoc
3+
// * networking/using-ptp.adoc
44

55
[id="cnf-installing-amq-interconnect-messaging-bus_{context}"]
66
= Installing the AMQ messaging bus

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

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
11
// Module included in the following assemblies:
22
//
3-
// * networking/configuring-ptp.adoc
3+
// * networking/using-ptp.adoc
44

55
[id="cnf-monitoring-fast-events-metrics-using-cli_{context}"]
66
= Monitoring PTP fast event metrics using the CLI

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

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
11
// Module included in the following assemblies:
22
//
3-
// * networking/configuring-ptp.adoc
3+
// * networking/using-ptp.adoc
44

55
[id="cnf-fast-event-metrics-in-prometheus_{context}"]
66
= Monitoring PTP fast event metrics in the web console

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

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
11
// Module included in the following assemblies:
22
//
3-
// * networking/configuring-ptp.adoc
3+
// * networking/using-ptp.adoc
44

55
[id="cnf-troubleshooting-common-ptp-operator-issues_{context}"]
66
= Troubleshooting common PTP Operator issues

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

Lines changed: 18 additions & 14 deletions
Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
11
// Module included in the following assemblies:
22
//
3-
// * networking/multiple_networks/configuring-ptp.adoc
3+
// * networking/using-ptp.adoc
44

55
[id="configuring-linuxptp-services-as-boundary-clock_{context}"]
66
= Configuring linuxptp services as boundary clock
@@ -137,12 +137,14 @@ spec:
137137
userDescription ;
138138
timeSource 0xA0
139139
phc2sysOpts: "-a -r" <9>
140-
recommend: <10>
141-
- profile: "profile1" <11>
142-
priority: 10 <12>
143-
match: <13>
144-
- nodeLabel: "node-role.kubernetes.io/worker" <14>
145-
nodeName: "compute-0.example.com" <15>
140+
ptpSchedulingPolicy: SCHED_OTHER <10>
141+
ptpSchedulingPriority: 65 <11>
142+
recommend: <12>
143+
- profile: "profile1" <13>
144+
priority: 10 <14>
145+
match: <15>
146+
- nodeLabel: "node-role.kubernetes.io/worker" <16>
147+
nodeName: "compute-0.example.com" <17>
146148
----
147149
<1> The name of the `PtpConfig` CR.
148150
<2> Specify an array of one or more `profile` objects.
@@ -153,12 +155,14 @@ spec:
153155
<7> The interface name to synchronize from.
154156
<8> The interface to synchronize devices connected to the interface.
155157
<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.
156-
<10> Specify an array of one or more `recommend` objects which define rules on how the `profile` should be applied to nodes.
157-
<11> Specify the `profile` object name defined in the `profile` section.
158-
<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.
159-
<13> Specify `match` rules with `nodeLabel` or `nodeName`.
160-
<14> Specify `nodeLabel` with the `key` of `node.Labels` from the node object.
161-
<15> Specify `nodeName` with `node.Name` from the node object.
158+
<10> Scheduling policy for ptp4l and phc2sys processes. Default value is `SCHED_OTHER`. Use `SCHED_FIFO` on systems that support FIFO scheduling.
159+
<11> Integer value from 1-65 used to set FIFO priority for `ptp4l` and `phc2sys` processes. Required if `SCHED_FIFO` is set for `ptpSchedulingPolicy`.
160+
<12> Specify an array of one or more `recommend` objects that define rules on how the `profile` should be applied to nodes.
161+
<13> Specify the `profile` object name defined in the `profile` section.
162+
<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.
163+
<15> Specify `match` rules with `nodeLabel` or `nodeName`.
164+
<16> Specify `nodeLabel` with the `key` of `node.Labels` from the node object.
165+
<17> Specify `nodeName` with `node.Name` from the node object.
162166

163167
. Create the CR by running the following command:
164168
+
@@ -169,7 +173,7 @@ $ oc create -f boundary-clock-ptp-config.yaml
169173

170174
.Verification steps
171175

172-
. Check that the `PtpConfig` profile is applied to node.
176+
. Check that the `PtpConfig` profile is applied to the node.
173177

174178
.. Get the list of pods in the `openshift-ptp` namespace by running the following command:
175179
+

0 commit comments

Comments
 (0)