[finalize-warmboot.sh] reset cpufreq governor to default

[stepanblyschak]

Why I did it

Set cpufreq.default_governor to performance for faster boot time. We observe consistent 1 sec improvement across several devices.

The change in finalize-warmboot.sh restores the default governor after fast or warm boot is finished.

NOTE: This will apply to upgrades starting from 202405 since this is set in shutdown path to avoid any extra scripts running at boot time. Upgrade from older versions/branches will require a runtime patch to fast-reboot and warm-reboot script.

Work item tracking

• Microsoft ADO (number only):

How I did it

After fast or warm boot is finished restore to default governor.

How to verify it

Run fast-reboot or warm-reboot. Check:

admin@sonic:~$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
performance

After boot is finalized check that it is reset back to default:

admin@sonic:~$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
schedutil

Tested with https://github.com/sonic-net/sonic-utilities/pull/3435

Which release branch to backport (provide reason below if selected)

• [ ] 201811
• [ ] 201911
• [ ] 202006
• [ ] 202012
• [ ] 202106
• [ ] 202111
• [ ] 202205
• [ ] 202211
• [ ] 202305
• [ ] 202311
• [x] 202405

Tested branch (Please provide the tested image version)

• [ ]
• [ ]

Description for the changelog

Link to config_db schema for YANG module changes

A picture of a cute animal (not mandatory but encouraged)

[bingwang-ms]

@saiarcot895 @vaibhavhd Can you please help review?

[liat-grozovik]

@vaibhavhd kindly reminder for code review feedback/approval.

[vaibhavhd]

Comments are open on utilities PR.

[stepanblyschak]

/azpw run Azure.sonic-buildimage

[mssonicbld]

/AzurePipelines run Azure.sonic-buildimage

[azure-pipelines[bot]]

Azure Pipelines successfully started running 1 pipeline(s).

[dgsudharsan]

@qiluo-msft can you please help merge?

[bingwang-ms]

@stepanblyschak Can you raise a PR to 202405 to do the cherry-pick? The auto cherry-pick is not working for this PR.

[mssonicbld]

Cherry-pick PR to 202405: https://github.com/sonic-net/sonic-buildimage/pull/21030