tmpfs panic

Hi there,

at contemporary RELENG_7/amd64

panic at umount phase (shutdown -r in progress):

(kgdb) bt
#0  doadump () at pcpu.h:194
#1  0x0000000000000010 in ?? ()
#2  0xffffffff8021f530 in boot (howto=260) at 
/usr/src/sys/kern/kern_shutdown.c:418
#3  0xffffffff8021f94d in panic (fmt=0x104 <Address 0x104 out of bounds>) at 
/usr/src/sys/kern/kern_shutdown.c:572
#4  0xffffffff80394a64 in trap_fatal (frame=0xffffff00012129c0, 
eva=18446742974216866000) at /usr/src/sys/amd64/amd64/trap.c:724
#5  0xffffffff80394e35 in trap_pfault (frame=0xffffffffd517e8d0, usermode=0) at 
/usr/src/sys/amd64/amd64/trap.c:641
#6  0xffffffff803957db in trap (frame=0xffffffffd517e8d0) at 
/usr/src/sys/amd64/amd64/trap.c:410
#7  0xffffffff8037b54e in calltrap () at 
/usr/src/sys/amd64/amd64/exception.S:169
#8  0xffffffff802138dd in _mtx_lock_sleep (m=0xffffff00b41cbe78, 
tid=18446742974216874432, opts=Variable "opts" is not available.
) at /usr/src/sys/kern/kern_mutex.c:335
#9  0xffffffff80297b25 in vgone (vp=0xffffff00b41cbd90) at 
/usr/src/sys/kern/vfs_subr.c:2471
#10 0xffffffff8074d10e in tmpfs_alloc_vp (mp=0xffffff000933c978, 
node=0xffffff00cef55000, lkflag=4098, vpp=0xffffffffd517ea98, 
td=0xffffff00012129c0)
    at /usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_subr.c:396
#11 0xffffffff8074c868 in tmpfs_root (mp=Variable "mp" is not available.
) at /usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_vfsops.c:388
#12 0xffffffff80294b27 in dounmount (mp=0xffffff000933c978, flags=524288, 
td=0xffffff00012129c0) at /usr/src/sys/kern/vfs_mount.c:1273
#13 0xffffffff80297ecc in vfs_unmountall () at 
/usr/src/sys/kern/vfs_subr.c:2936
#14 0xffffffff8021f7c9 in boot (howto=0) at 
/usr/src/sys/kern/kern_shutdown.c:400
#15 0xffffffff8021fab9 in reboot (td=Variable "td" is not available.
) at /usr/src/sys/kern/kern_shutdown.c:172
#16 0xffffffff803950ba in syscall (frame=0xffffffffd517ec70) at 
/usr/src/sys/amd64/amd64/trap.c:852
#17 0xffffffff8037b75b in Xfast_syscall () at 
/usr/src/sys/amd64/amd64/exception.S:290
#18 0x00000000004084ec in ?? ()
Previous frame inner to this frame (corrupt stack?)

Also, active tmpfs usage easy leads to 
"swap zone exhausted, increase kern.maxswzone", even with 2G RAM + 4G swap and 
approx 2-3G of tmpfs in use -- any hints?

Thanks in advance.

Sincerely,
D.Marck                                     [DM5020, MCK-RIPE, DM3-RIPN]
[ FreeBSD committer:                                 marck_at_FreeBSD.org ]
------------------------------------------------------------------------
*** Dmitry Morozovsky --- D.Marck --- Wild Woozle --- marck_at_rinet.ru ***
------------------------------------------------------------------------