On Wed, Jun 17, 2026 at 10:18 PM Ryan Libby <[email protected]> wrote:
>
> The branch main has been updated by rlibby:
>
> URL:
> https://cgit.FreeBSD.org/src/commit/?id=08180f1b613b6fe000135efa28b7c3293cbf1683
>
> commit 08180f1b613b6fe000135efa28b7c3293cbf1683
> Author: Ryan Libby <[email protected]>
> AuthorDate: 2026-06-18 03:52:53 +0000
> Commit: Ryan Libby <[email protected]>
> CommitDate: 2026-06-18 04:05:43 +0000
>
> witness: actually set read-only tunables in time for witness_startup
>
> SYSCTL_XXX with CTLFLAG_RDTUN and without CTLFLAG_NOFETCH should not be
> used for values that are needed before SI_SUB_KLD. Otherwise they are
> tuned after they are needed. Set CTLFLAG_RDTUN | CTLFLAG_NOFETCH for
> the debug.witness.witness_count and debug.witness.skipspin sysctls and
> add separate tunables for them, which run at SI_SUB_TUNABLES time, i.e.,
> in time for witness_startup.
>
> Reviewed by: kib, markj
> Sponsored by: Dell Inc.
> Differential Revision: https://reviews.freebsd.org/D57613
My dev VM instapanics on boot, and I've bisected it to this change.
Apparently it doesn't affect everybody, or it would've been reported
already. So I'm not asking you to revert it. But could you please
take a look at the problem?
Stack trace:
---<<BOOT>>---
Copyright (c) 1992-2026 The FreeBSD Project.
Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994
The Regents of the University of California. All rights reserved.
FreeBSD is a registered trademark of The FreeBSD Foundation.
FreeBSD 16.0-CURRENT #25 n286717-a9e12d3ec8bd: Mon Jun 22 16:50:06 MDT 2026
[email protected]:/usr/obj/usr/home/somers/src/freebsd.org/src/main/amd64.amd64/sys/GENERIC
amd64
FreeBSD clang version 21.1.8 (https://github.com/llvm/llvm-project.git
llvmorg-21.1.8-0-g2078da43e25a)
WARNING: WITNESS option enabled, expect reduced performance.
SRAT: Ignoring memory at addr 0xff000000
panic: physical address 0x4af918000 not covered by the DMAP
cpuid = 0
time = 1
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x36/frame 0xffffffff8293bd60
vpanic() at vpanic+0x149/frame 0xffffffff8293be90
panic() at panic+0x43/frame 0xffffffff8293bef0
pmap_map() at pmap_map+0x2c/frame 0xffffffff8293bf00
vm_page_startup() at vm_page_startup+0x71c/frame 0xffffffff8293bf90
vm_mem_init() at vm_mem_init+0x1a/frame 0xffffffff8293bfa0
mi_startup() at mi_startup+0x1ed/frame 0xffffffff8293bff0
KDB: enter: panic
[ thread pid 0 tid 0 ]
Stopped at kdb_enter+0x33: movq $0,0x15ad202(%rip)
/boot/loader.conf contents:
kern.boottrace.enabled=1
debug.kasan.panic_on_violation=0
debug.kmsan.panic_on_violation=0
debug.witness.witness_count=49152
