panic: pmap active 0xfffff8001b7154b8

[Johan Schuijt-Li]

Hi,

We’ve been seeing (seemingly) random reboots on 10.1-RELEASE virtual machines (KVM virtualisation) on our production servers. In an attempt to determine what was causing this we’ve switched to running a kernel with INVARIANTS enabled. This resulted for us in the following panic:

Unread portion of the kernel message buffer:
panic: pmap active 0xfffff8001b7154b8
cpuid = 3
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe03dd1493a0
kdb_backtrace() at kdb_backtrace+0x39/frame 0xfffffe03dd149450
vpanic() at vpanic+0x126/frame 0xfffffe03dd149490
kassert_panic() at kassert_panic+0x139/frame 0xfffffe03dd149500
pmap_remove_pages() at pmap_remove_pages+0x8c/frame 0xfffffe03dd1495f0
exec_new_vmspace() at exec_new_vmspace+0x16a/frame 0xfffffe03dd149650
exec_elf64_imgact() at exec_elf64_imgact+0x658/frame 0xfffffe03dd149720
kern_execve() at kern_execve+0x5e4/frame 0xfffffe03dd149a80
sys_execve() at sys_execve+0x37/frame 0xfffffe03dd149ae0
amd64_syscall() at amd64_syscall+0x25a/frame 0xfffffe03dd149bf0
Xfast_syscall() at Xfast_syscall+0xfb/frame 0xfffffe03dd149bf0
--- syscall (59, FreeBSD ELF64, sys_execve), rip = 0x80158af1a, rsp = 0x7fffffffac38, rbp = 0x7fffffffad40 ---


I’ve only come across one other report here (without result unfortunate):
https://lists.freebsd.org/pipermail/freebsd-current/2014-June/050827.html <https://lists.freebsd.org/pipermail/freebsd-current/2014-June/050827.html>

Are other people aware of this issue or working on this?

I can provide access to a VM with a kernel dump and the kernel build for extra information if needed.

- Johan