| Message ID | ZIL4mIJng57g33zT@righiandr-XPS-13-7390 |
|---|---|
| State | New |
| Headers | show |
| Series | [ANNOUNCE] annotations v4 and how to deal with kernel .config | expand |
diff --git a/debian.master/config/annotations b/debian.master/config/annotations index 24cec55b1b20b..cfb2dc5eb3757 100644 --- a/debian.master/config/annotations +++ b/debian.master/config/annotations @@ -732,8 +732,8 @@ CONFIG_X509_CERTIFICATE_PARSER note<'module signing'> CONFIG_X86_ACPI_CPUFREQ policy<{'amd64': 'y'}> CONFIG_X86_ACPI_CPUFREQ note<'not autoloadable'> -CONFIG_X86_KERNEL_IBT policy<{'amd64': 'n'}> -CONFIG_X86_KERNEL_IBT note<'LP: #1980484'> +CONFIG_X86_KERNEL_IBT policy<{'amd64': 'y'}> +CONFIG_X86_KERNEL_IBT note<'Enable Intel Indirect Branch Tracking (IBT) as a test'> CONFIG_X86_PCC_CPUFREQ policy<{'amd64': 'y'}> CONFIG_X86_PCC_CPUFREQ note<'not autoloadable'>
As many of you may have noticed already, some of our kernels already migrated to the new annotations model (v4), removing any .config chunk from their git repository. What is annotations? ==================== Annotations is a JSON-like file (one for each kernel) that is used to store all the kernel config options (with optional notes) for all the kernel's supported architectures and flavours. Starting with 22.04 (Jammy Jellyfish), Ubuntu kernels are now using only annotations to generate their corresponding .config. Why don't we simply use .config? ================================ Ubuntu provides a wide variety of kernels for many different architectures and flavours, such as generic, lowlatency, cloud kernels, kvm, etc. Maintaining a separate .config for each of these kernels would be extremely challenging. Moreover, we need to make sure that certain .config options do not change across kernel updates and rebases, in order to have a kernel functional for the scope that it was designed for. The main goal of annotations is to make the maintenance of multiple kernel .config easier and more reliable. How do I change a particular .config then? ========================================== You have two options: 1) change all the kernel configs that you want, produce a standard .config and import it in annotations, specifying the appropriate architecture and flavour, for example: $ ./debian/scripts/misc/annotations --arch amd64 --flavour generic \ --import .config 2) modify `debian.<kernel_name>/config/annotations` directly or using the annotations script, for example, enable X86_KERNEL_IBT on amd64, flavour generic: $ ./debian/scripts/misc/annotations --arch amd64 --flavour generic \ --config CONFIG_X86_KERNEL_IBT --write y \ --note "Enable Intel Indirect Branch Tracking (IBT) as a test" Then run a `git diff` to show you the actual change(s). For example, the following could be submitted as a valid patch to this mailing list: $ git diff How to generate the .config for a specific kernel? ================================================== To generate a standard .config for a specific architecture and flavour run the following command (i.e., amd64, flavour generic): $ ./debian/scripts/misc/annotations --arch amd64 --flavour generic > .config The generated .config will have all the config options for amd64, flavour generic used by this particular kernel. See also ======== - Kernel configuration in Ubuntu (https://discourse.ubuntu.com/t/kernel-configuration-in-ubuntu/35857) -Andrea