SMP Kernel Panic in 6.1-RC1 during mount root filesystem

[Ying-Chih Kuo]

sorry for last mail ,it encoded.

I have a quad xeon piii-550 box ,it works on 4.11 SMP very well.
now i "install" (not upgrade)  6.1-RC1 in this box.
it works very well without SMP, but with SMP (with or with acpi) ,always
PANIC,PANIC,PANIC...

i got DDB stack trace, http://www.freebsd.org/cgi/query-pr.cgi?pr=96049

help me,please.

yckuo