Re: Kernel modules not loading on 15-prerelease

On Sep 6, 2025, at 10:16, Mark Millard <marklmi@yahoo.com> wrote:

> On Sep 6, 2025, at 08:18, bob prohaska <fbsd@www.zefox.net> wrote:
> 
>> On Fri, Sep 05, 2025 at 09:17:06AM -0700, Mark Millard wrote:
>>> 
>>>> Run # make cleanworld once.
>>> 
>>> In your odd context, "make clean" may well be better
>>> for before starting the builds.
>> 
>> Interestingly, "make clean" wasn't successful, but make 
>> cleandir resulted in a new build of kernel and modules.
> 
> There is cleankernel and cleanworld as well.
> 
> Good to know that clean does not do what I was thinking.
> Thanks.
> 
>>>> If objects don't have .meta files then META_MODE won't do the right thing on an incremental build. 1
>>>> FreeBSD buildworld will now create meta files to improve the performance of future builds.
>>> 
>>> So: how to get a valid kernel/module-set without
>>> first building all of the world:
>>> 
>>> FIRST: deal with having /etc/src-env.conf include a
>>> line with:
>>> 
>>> WITH_META_MODE=
>>> 
>>> (Your choice if you want the YES or some text.)
>>> 
>>> NOTE: I make the assumption that you want to use
>>>     /etc/src-env.conf instead of command line
>>>     content.
>> 
>> As a matter of curiosity, is /usr/local/etc/src-env.conf
>> in the search path? This seems like a local parameter.
> 
> # man 5 src.conf reports:
> 
> FILES
>     /etc/src.conf
>     /etc/src-env.conf
>     /usr/share/mk/bsd.own.mk
> 
> and has no reference to: /usr/local/
> 
> Building and installing is meant to be possible
> without /usr/local/ being populated with anything:
> it is all system stuff, not ports or port packages.
> 
> /etc/fstab also has "local parameters", for example.
> But /usr/local/etc/fstab is not a thing as far as I
> know.
> 
>>> # cd /usr/src/ # (or where ever you have your source)
>>> # make clean # not something that you would normally do
> 
> Maybe that should have been:
> 
> # make cleankernel # not something that you would normally do
> 
>>> # make kerneltoolchain
>> 
>> I'd forgotten about the kernel-toolchain target. That
>> sped things up considerably.
> 
> If you want to update the kernel before building the
> world, the partial system update by kerneltoolchain
> allows getting to use of the new kernel sooner, for
> sure.
> 
> The later buildworld still takes the time do do the
> rest of the work for that. So, probably there is no
> overall time savings.
> 
>>> NOTE: I do not know your detailed choices about handling
>>>     kernel updates so you may have more related to the
>>>     installkernel than I show. For example, you might
>>>     deliberately keep a copy of the old kernel under
>>>     some alternate name before updating the default
>>>     named one. (There are other possibilities.)
>> 
>> Ordinarily, I do not. If trouble is expected I often 
>> cp -R boot/kernel.old /boot/kernel.spare for an extra
>> level of redundancy.
> 
> If the likes of just cleankernel was used earlier,
> possibly here for your specific problem:
> 
> # make cleanworld # not something that you would normally do

I probably should have explicitly noted here that if both
the kernel and the world are to be built with META_MODE
from scratch:

# make cleankernel cleanworld # not something that you would normally do

so that both the kernel and world will rebuild everything
with filemon and META_MODE tracking and recording the
activity.

> before anything that leads to starting the buildworld .
> 
>>> kldload -n filemon
>>> cd /usr/src/ # or my equivalent for a specific source tree
>>> 
>>> That is in order to establish context for later commands
>>> in the script and for META_MODE use.
>>> 
>>> I happen to choose to not start filemon unless I'm
>>> starting a system software build, avoiding any overhead
>>> if I've not done any system builds yet.
>> 
>> That seems a good idea which never crossed my mind... 
>> Is there any estimate how much overhead filemon imposes?
> 
> Unsure. My guess is that META_MODE (or other related if
> used) are the only things registering a use of filemon .
> 
> But just being loaded uses memory in your small arm board,
> 1 GiByte of RAM, type of context, for example. When you
> are not doing system builds, I've no clue if the memory
> use is enough for you to care.
> 
>> Many thanks for your help. My misunderstanding of meta-mode
>> use was rather profound.


===
Mark Millard
marklmi at yahoo.com