Kernel configuration for distributions [LWN.net]

Kernel configuration for distributions

Posted Jul 20, 2012 4:46 UTC (Fri) by dirtyepic (guest, #30178)
Parent article: Kernel configuration for distributions

While I support this completely, I also think a lot of pain in configuring a kernel would be relieved by providing more user-centric information in the help text. Most help documents what an option does (more or less), but rarely does it give any indication of why you might want it to do that. I have a text file that I've slowly filled over the last 6 years with pointers to all the random emails, references, blog posts, LWN articles, and research I've had to do to just figure out if I actually need to enable a particular option or not.

I know the kernel is very complex and needs to serve the needs of all types of users and many options are going to require you to do a little research to be able to make an educated choice, but for the basic stuff it'd be nice to see a "Disabling this will make consolekit/powertop/systemd puke on your shoes." or "Here's how to determine if your system supports this kind of device." once in a while.

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Kernel configuration for distributions

Posted Jul 20, 2012 16:04 UTC (Fri) by apoelstra (subscriber, #75205) [Link] (1 responses)

>I have a text file that I've slowly filled over the last 6 years with pointers to all the random emails, references, blog posts, LWN articles, and research I've had to do to just figure out if I actually need to enable a particular option or not.

If this text file is in a readable (and polite) state, it'd be great if you could post it somewhere so others can learn from it. I've tried compiling a kernel 4 or 5 times over the last decade, and never got one that booted.

Kernel configuration for distributions

Posted Jul 21, 2012 12:37 UTC (Sat) by foom (subscriber, #14868) [Link]

Indeed. The only way I get working custom kernels is by taking my distro kernel's config and modifying it slightly.

Kernel configuration for distributions

Posted Jul 22, 2012 20:53 UTC (Sun) by Julie (guest, #66693) [Link]

>While I support this completely, I also think a lot of pain in configuring a kernel would be relieved by providing more user-centric information in the help text.

As someone who spends a lot of free time testing mainline -rc and -next kernels, I totally and absolutely agree - and maybe for kernel maintainers of specific kernel features and modules to check from time to time that their help text is up-to-date - obsolete documentation has caught me out more than once, and not only wasn't I knowledgeable enough about those features/modules to provide an update patch, I didn't even know where to start looking :-/

Tips like make localmodconfig are really useful, but only go so far, and the trial-and-error approach of squeezing a kernel down gets old *really* quickly. But it has to be done; if simply building a new kernel takes a lot longer with a bloated distro config, imagine how much worse this is when you encounter a bug and have to do a bisect...and all those extra new and sometimes arcane features disappearing and popping up again as you whang back and forth from one kernel version to another...

The last time I had to pare down a distro kernel for a new test setup it took me more than *two weeks* to come up with something that was minimal enough to be efficient and still worked, and even then I had delayed starting it until I had a long weekend because I knew it was going to be such a PITA.

Some of this can be put down to naivety and lack of time, but I'll bet that's the case with a lot of testers - we're not developers and are doing this in our spare hours, after all.

>I have a text file that I've slowly filled...

Like the others say, it would be great if this could somehow be available to the rest of us...possibly at kernelnewbies?