ERL (was: ELF - panic on installworld)

[Wolfgang Zenker]

* Alexander Kabaev <kabaev at gmail.com> [180306 03:15]:
> On Mon, 5 Mar 2018 20:30:42 -0500
> Alexander Kabaev <kabaev at gmail.com> wrote:

>> On Mon, 5 Mar 2018 22:45:28 +0100
>> Wolfgang Zenker <wolfgang at lyxys.ka.sub.org> wrote:

>>> Sorry for the messup in the subject.

>>> * Wolfgang Zenker <wolfgang at lyxys.ka.sub.org> [180305 22:16]:  

>>>> I'm trying to run installworld using 11-STABLE on an Ubiquity Edge
>>>> Router Lite (mips64, 2 cores, 512 MB Ram). Unfortunately I haven't
>>>> managed to finish the installworld yet, I always get a
>>>> panic: kernel stack overflow - trapframe at 0xffffffff80917eb0
>>>> in slightly different places during the installworld. Of the 4
>>>> panics I have seen on the serial console, 3 had the trapframe at
>>>> 0xffffffff80917eb0 and one at 0xffffffff80915eb0
>>>> /usr/src and /usr/obj are nfs-mounted, and I have configured
>>>> almost 2 GB of swap. The build was done in a Qemu environment.

>>>> Any hints how to proceed from here?

>> NFS is is known kernel stack hog. Try increasing KSTACK_PAGES up from
>> whatever defaults in your kernel config file. IIRC, mips defaults to 2
>> pages, which is not enough for your workload.

> I got reminded privately that variable stack sizes do not work on MIPS
> without extra patches:

True; due to KSTACK_PAGES being set to 2 unconditionally in
sys/mips/include/param.h, buildkernel fails when KSTACK_PAGES is added
to the conf file. Adding an "#ifndef KSTACK_PAGES" to param.h allows
buildkernel to work, but the resulting kernel panics at boot.

>  http://people.freebsd.org/~sson/mips/kstack/kstack_large_page.diff

That looks like quite a bit more than just a simple increase of the
kernel stack space. I think I will go with updating by building media
images (and less frequent upgrades) instead.

> Not sure if it can still be applied to -current.

I will at least try it once on 11-STABLE, just to find out. Will take a
while, currently down with flu and not really that good with
concentrating on that task.

Wolfgang