[SRU][N/P/R:linux-azure][PATCH 0/1] Include cppc_cpufreq in linux-modules
Bryan Fraschetti
bryan.fraschetti at canonical.com
Wed Dec 3 15:04:24 UTC 2025
BugLink: https://bugs.launchpad.net/bugs/2119465
[Impact]
Azure requested cppc_cpufreq to be available by default (without need to install modules-extra). Address this by moving it to linux-modules.
Include cppc_cpufreq module in linux-modules package instead of linux-modules-extra so that cpufreq is enabled by default (without the need to install linux-modules-extra).
The fix is fairly simple, add the cppc_cpufreq.ko modules to azure-nvidia.inclusion-list in linux-azure-nvidia package, and to azure.inclusion-list for the linux-azure package. The objective is for the kernel module to be available in all 6.8 and newer linux-azure kernels
Note that this has been fixed in linux-azure-nvidia as of linux-azure-nvidia - 6.8.0-1025.27. For linux-azure, the fix needs to be applied to Noble, Plucky, and Resolute. Questing can be skipped due to the commit at [1], which consolidates linux-modules and linux-modules-extra due to improvements to zst compression as outlined in LP: #2042831 [2]. These improvements allow for the compression of both sets to be smaller than the original compressed size of the linux-modules set, thereby, negating the benefits of the separation. If the patch at [1] is applied to Resolute before the one for this LP bug is applied, then this patch can be dropped for Resolute. Otherwise this patch should be applied to Resolute in the interim to avoid a regression.
[1] https://git.launchpad.net/~canonical-kernel/ubuntu/+source/linux-azure/+git/questing/commit/debian.azure/control.d?h=master-next&id=1f36467420212d3073f7ee78bf7cb16b5c340146
[2] https://bugs.launchpad.net/bugs/2042831
[Test Case]
Currently cppc_cpufreq is not included in linux-modules package.
root at flavio:/home/ubuntu# uname -rv
6.8.0-1019-azure-nvidia #20-Ubuntu SMP Fri Jun 27 23:52:00 UTC 2025
root at flavio:/home/ubuntu# lsmod | grep cpufreq
root at flavio:/home/ubuntu#
root at flavio:/home/ubuntu# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
cat: /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor: No such file or directory
Preparing a test kernel with the fix and installing only the linux-image and linux-modules package, cppc_cpufreq is present.
ubuntu at flavio:~$ uname -rv
6.8.0-1020-azure-nvidia #21 SMP Mon Aug 4 16:37:34 UTC 2025
root at flavio:/home/ubuntu# lsmod | grep cpufreq
cppc_cpufreq 262144 0
root at flavio:/home/ubuntu# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
ondemand
[Where problems could occur]
The fix just adds a module in linux-modules package. Not any severe regressions expected. However, those who expected to find this module in modules-extra will not find there anymore.
[Other]
Originally the request was only for linux-azure-nvidia, for Noble, 6.8, which has since been fixed. The request is to now add the module to linux-azure for 6.8 and newer kernels. The existing linux-azure-nvidia bug report has been updated to reflect this and include linux-azure as a target, rather than creating a new bug.
SF#413581
Bryan Fraschetti (1):
UBUNTU: [Config] azure: add cppc_cpufreq to azure.inclusion-list
debian.azure/control.d/azure.inclusion-list | 1 +
1 file changed, 1 insertion(+)
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2.43.0
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