port-arm/55922: Kernel panics with nvme+gpt on Pinebook Pro

[bsiegert%gmail.com@localhost]

>Number:         55922
>Category:       port-arm
>Synopsis:       Kernel panics with nvme+gpt on Pinebook Pro
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    port-arm-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Jan 12 14:50:00 +0000 2021
>Originator:     Benny Siegert
>Release:        NetBSD 9.99.76
>Organization:
The NetBSD Foundation
>Environment:
NetBSD 9.99.76 kernel (since update to 9.99.77) + NetBSD 9 userland, Pinebook Pro, evbarm-aarch64
>Description:
I added an NVMe drive to the Pinebook Pro and created a GPT with some partitions on it (root, EFI, swap, home). The kernel is loaded from eMMC but the root FS is on the NVMe.

Trying to build a Rust program using MAKE_JOBS=6 (thus, highly parallel, using all cores), I can make the machine crash after several minutes of such activity.

gdb is responsive but "sync" hangs for obvious reasons.

Here are two photos I snapped of the backtraces:

https://photos.app.goo.gl/f58UfkoURGxTjF3j8
https://photos.app.goo.gl/JF25NDTEDYK4Uvt26
 
The backtraces are a little different but both of them are in writes to the file system (below dofilewrite).
>How-To-Repeat:
- aarch64 system (Pinebook Pro)
- root FS on NVME, FFS on GPT
- build some Rust program (in my case, wip/sccache, which is not committed yet).
>Fix:
?