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Bug 1688458 - G.8275.1 Telecom Profile PTP Phase accuracy
Summary: G.8275.1 Telecom Profile PTP Phase accuracy
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux 8
Classification: Red Hat
Component: linuxptp
Version: 8.1
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: rc
: 8.0
Assignee: Miroslav Lichvar
QA Contact: Yalin.Li
URL:
Whiteboard:
: 1688858 (view as bug list)
Depends On: 1680888
Blocks:
TreeView+ depends on / blocked
 
Reported: 2019-03-13 18:24 UTC by sushil kulkarni
Modified: 2020-11-14 12:01 UTC (History)
4 users (show)

Fixed In Version: linuxptp-2.0-4.el8
Doc Type: If docs needed, set a value
Doc Text:
Clone Of:
Environment:
Last Closed: 2019-11-05 20:56:55 UTC
Type: Bug
Target Upstream Version:
Embargoed:
sukulkar: mirror+

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHEA-2019:3380 0 None None None 2019-11-05 20:57:01 UTC

Description sushil kulkarni 2019-03-13 18:24:37 UTC 
More Details on the Requirement - https://docs.engineering.redhat.com/pages/viewpage.action?pageId=63300108

User Story:

As a 5G cRAN edge cloud provider, I need accurate PTP clock phase accuracy on RHEL8 with RHEL-RT and RT-KVM in order to deploy cRAN applications on RHEL
Usecase 1- Ordinary Clock (GM and Slave only) 

Ethernet Multicast and 2-Way messaging

Measure phase accuracy with oscilloscope and 1 PPS clock out from NIC (solarflare or other)
Comment 2 Tomáš Hozza 2019-04-26 09:56:50 UTC 
*** Bug 1688858 has been marked as a duplicate of this bug. ***
Comment 3 Miroslav Lichvar 2019-06-10 12:46:40 UTC 
Switching to MODIFIED in order to add the bug to errata.
Comment 4 Yalin.Li 2019-07-12 09:29:24 UTC 
Hi Sushil,

Since we don't have the oscilloscope and the NIC with PPS out. I just ran the ptp4l with g.8275.1 profile and The result seems good. Below are some related data about accuracy:
        maxOffset minOffset rmsOffset  maxDelay  minDelay  rmsDelay
  Ptp4l       703         0        36      2221      2187      2203
Phc2sys        84         0        25      2636      2569      2610

Should I set it to verified?
Comment 5 sushil kulkarni 2019-07-25 19:58:47 UTC 
Hi Miroslav, Hangbin,

Adding needinfo for your input.

Thanks!
Sushil
Comment 6 Miroslav Lichvar 2019-07-29 15:33:20 UTC 
I have not written the requirements, so I'm not sure what's acceptable. They talk about a sub-microsecond accuracy and measuring a PPS signal with an oscilloscope. I don't see that verified yet. The delays reported by ptp4l and phc2sys from comment #4 would give an upper bound on accuracy better than 4 microseconds. Also, the first comment mentions KVM, so I guess this would need to include also some tests of a KVM guest.
Comment 8 Yalin.Li 2019-08-09 07:54:24 UTC 
        maxOffset minOffset rmsOffset  maxDelay  minDelay  rmsDelay
  Ptp4l       266         0         9       178       160       168
Phc2sys        38         0        12       483       390       469
the max estimated error is 574ns
the offset rms in VM is 10.779ns

Setup:
host kernel:4.18.0-128.rt24.73.el8.x86_64
guest kernel: 4.18.0-128.rt24.73.el8.x86_64
NIC:Mellanox-MT27800_Family_25G on both master side and slave side. Two NICs are connected to a QFX5200 which has enabled the TC.

driver:
[root@hp-dl380g10-04 8275.1]# ethtool -i ens2f0
driver: mlx5_core
version: 5.0-0
firmware-version: 16.25.1020 (MT_0000000080)
expansion-rom-version: 
bus-info: 0000:37:00.0
supports-statistics: yes
supports-test: yes
supports-eeprom-access: no
supports-register-dump: no
supports-priv-flags: yes

Package:
Installed Packages
Name         : linuxptp
Version      : 2.0
Release      : 4.el8
Architecture : x86_64
Size         : 838 k
Source       : linuxptp-2.0-4.el8.src.rpm
Repository   : @System
From repo    : beaker-AppStream
Summary      : PTP implementation for Linux
URL          : http://linuxptp.sourceforge.net/
License      : GPLv2+
Description  : This software is an implementation of the Precision Time Protocol (PTP)
             : according to IEEE standard 1588 for Linux. The dual design goals are to provide
             : a robust implementation of the standard and to use the most relevant and modern
             : Application Programming Interfaces (API) offered by the Linux kernel.
             : Supporting legacy APIs and other platforms is not a goal.

[root@hp-dl380g10-04 8275.1]#
Comment 9 Yalin.Li 2019-08-13 03:32:45 UTC 
Since we cannot verify the real accuracy now, and all data reported by process is not degraded. Set it to verified with SanityOnly.
Comment 11 errata-xmlrpc 2019-11-05 20:56:55 UTC 
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHEA-2019:3380
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