Re: (r257598) panic: Assertion tmp-tm_pages_used == 0 failed at /usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_vfsops.c:316

2013-11-04 Thread Allan Jude
On 2013-11-04 09:35, Bryan Drewery wrote:
 11.0-CURRENT #87 r257598

 During a poudriere build.

 It creates a tmpfs, builds a port in a jail using that tmpfs and then
 removes the tmpfs and recreate the tmpfs before building the next port.

 panic: Assertion tmp-tm_pages_used == 0 failed at 
 /usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_vfsops.c:316
 cpuid = 9
 KDB: stack backtrace:
 db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 
 0xfe1247ee57a0
 kdb_backtrace() at kdb_backtrace+0x39/frame 0xfe1247ee5850
 vpanic() at vpanic+0x126/frame 0xfe1247ee5890
 kassert_panic() at kassert_panic+0x136/frame 0xfe1247ee5900
 tmpfs_unmount() at tmpfs_unmount+0x163/frame 0xfe1247ee5930
 dounmount() at dounmount+0x41f/frame 0xfe1247ee59b0
 sys_unmount() at sys_unmount+0x356/frame 0xfe1247ee5ae0
 amd64_syscall() at amd64_syscall+0x265/frame 0xfe1247ee5bf0
 Xfast_syscall() at Xfast_syscall+0xfb/frame 0xfe1247ee5bf0
 --- syscall (22, FreeBSD ELF64, sys_unmount), rip = 0x8008a02fa, rsp = 
 0x7fffd198, rbp = 0x7fffd2b0 ---
 Uptime: 44m40s
 (kgdb) #0  doadump (textdump=1) at pcpu.h:219
 #1  0x808bcf87 in kern_reboot (howto=260)
 at /usr/src/sys/kern/kern_shutdown.c:447
 #2  0x808bd495 in vpanic (fmt=value optimized out,
 ap=value optimized out) at /usr/src/sys/kern/kern_shutdown.c:754
 #3  0x808bd326 in kassert_panic (fmt=value optimized out)
 at /usr/src/sys/kern/kern_shutdown.c:642
 #4  0x81e159d3 in tmpfs_unmount (mp=0xf810502cd660,
 mntflags=value optimized out)
 at /usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_vfsops.c:316
 #5  0x8095e1af in dounmount (mp=0xf810502cd660, flags=134742016,
 td=0xf8013d57a490) at /usr/src/sys/kern/vfs_mount.c:1324
 #6  0x8095dd66 in sys_unmount (td=0xf8013d57a490,
 uap=0xfe1247ee5b80) at /usr/src/sys/kern/vfs_mount.c:1212
 #7  0x80cb7d75 in amd64_syscall (td=0xf8013d57a490, traced=0)
 at subr_syscall.c:134
 #8  0x80c9c90b in Xfast_syscall ()
 at /usr/src/sys/amd64/amd64/exception.S:391
 #9  0x0008008a02fa in ?? ()


Not sure if it is related, but I had a similar looking panic on a
10.0-BETA1 machine after doing a zfs receive:


 Fatal trap 12: page fault while in kernel mode
 cpuid = 5; apic id = 05
 fault virtual address = 0x378
 fault code= supervisor read data, page not present
 instruction pointer   = 0x20:0x8089bf51
 stack pointer = 0x28:0xfe1835d715d0
 frame pointer = 0x28:0xfe1835d71650
 code segment  = base 0x0, limit 0xf, type 0x1b
 = DPL 0, pres 1, long 1, def32 0, gran 1
 processor eflags  = interrupt enabled, resume, IOPL = 0
 current process   = 44435 (zfs)
 trap number   = 12
 panic: page fault
 cpuid = 5
 KDB: stack backtrace:
 #0 0x808e7580 at kdb_backtrace+0x60
 #1 0x808af065 at panic+0x155
 #2 0x80c8e292 at trap_fatal+0x3a2
 #3 0x80c8e569 at trap_pfault+0x2c9
 #4 0x80c8dcf6 at trap+0x5e6
 #5 0x80c75022 at calltrap+0x8
 #6 0x8094a32b at vflush+0x48b
 #7 0x8189e682 at zfs_umount+0x112
 #8 0x809434f5 at dounmount+0x4b5
 #9 0x80943004 at sys_unmount+0x3d4
 #10 0x80c8eb87 at amd64_syscall+0x357
 #11 0x80c7530b at Xfast_syscall+0xfb


-- 
Allan Jude




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Re: (r257598) panic: Assertion tmp-tm_pages_used == 0 failed at /usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_vfsops.c:316

2013-11-04 Thread Konstantin Belousov
On Mon, Nov 04, 2013 at 08:35:17AM -0600, Bryan Drewery wrote:
 11.0-CURRENT #87 r257598
 
 During a poudriere build.
 
 It creates a tmpfs, builds a port in a jail using that tmpfs and then
 removes the tmpfs and recreate the tmpfs before building the next port.
 
  panic: Assertion tmp-tm_pages_used == 0 failed at 
  /usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_vfsops.c:316
  cpuid = 9
  KDB: stack backtrace:
  db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 
  0xfe1247ee57a0
  kdb_backtrace() at kdb_backtrace+0x39/frame 0xfe1247ee5850
  vpanic() at vpanic+0x126/frame 0xfe1247ee5890
  kassert_panic() at kassert_panic+0x136/frame 0xfe1247ee5900
  tmpfs_unmount() at tmpfs_unmount+0x163/frame 0xfe1247ee5930
  dounmount() at dounmount+0x41f/frame 0xfe1247ee59b0
  sys_unmount() at sys_unmount+0x356/frame 0xfe1247ee5ae0
  amd64_syscall() at amd64_syscall+0x265/frame 0xfe1247ee5bf0
  Xfast_syscall() at Xfast_syscall+0xfb/frame 0xfe1247ee5bf0
  --- syscall (22, FreeBSD ELF64, sys_unmount), rip = 0x8008a02fa, rsp = 
  0x7fffd198, rbp = 0x7fffd2b0 ---
  Uptime: 44m40s
 
  (kgdb) #0  doadump (textdump=1) at pcpu.h:219
  #1  0x808bcf87 in kern_reboot (howto=260)
  at /usr/src/sys/kern/kern_shutdown.c:447
  #2  0x808bd495 in vpanic (fmt=value optimized out,
  ap=value optimized out) at /usr/src/sys/kern/kern_shutdown.c:754
  #3  0x808bd326 in kassert_panic (fmt=value optimized out)
  at /usr/src/sys/kern/kern_shutdown.c:642
  #4  0x81e159d3 in tmpfs_unmount (mp=0xf810502cd660,
  mntflags=value optimized out)
  at /usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_vfsops.c:316
  #5  0x8095e1af in dounmount (mp=0xf810502cd660, flags=134742016,
  td=0xf8013d57a490) at /usr/src/sys/kern/vfs_mount.c:1324
  #6  0x8095dd66 in sys_unmount (td=0xf8013d57a490,
  uap=0xfe1247ee5b80) at /usr/src/sys/kern/vfs_mount.c:1212
  #7  0x80cb7d75 in amd64_syscall (td=0xf8013d57a490, traced=0)
  at subr_syscall.c:134
  #8  0x80c9c90b in Xfast_syscall ()
  at /usr/src/sys/amd64/amd64/exception.S:391
  #9  0x0008008a02fa in ?? ()

Do you have core ?
I want to see the struct tmpfs_mount content for the tmpfs mount point
which caused the panic.


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Re: (r257598) panic: Assertion tmp-tm_pages_used == 0 failed at /usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_vfsops.c:316

2013-11-04 Thread Bryan Drewery

On 2013-11-04 10:27, Konstantin Belousov wrote:

On Mon, Nov 04, 2013 at 08:35:17AM -0600, Bryan Drewery wrote:

11.0-CURRENT #87 r257598

During a poudriere build.

It creates a tmpfs, builds a port in a jail using that tmpfs and then
removes the tmpfs and recreate the tmpfs before building the next 
port.


 panic: Assertion tmp-tm_pages_used == 0 failed at 
/usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_vfsops.c:316
 cpuid = 9
 KDB: stack backtrace:
 db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfe1247ee57a0
 kdb_backtrace() at kdb_backtrace+0x39/frame 0xfe1247ee5850
 vpanic() at vpanic+0x126/frame 0xfe1247ee5890
 kassert_panic() at kassert_panic+0x136/frame 0xfe1247ee5900
 tmpfs_unmount() at tmpfs_unmount+0x163/frame 0xfe1247ee5930
 dounmount() at dounmount+0x41f/frame 0xfe1247ee59b0
 sys_unmount() at sys_unmount+0x356/frame 0xfe1247ee5ae0
 amd64_syscall() at amd64_syscall+0x265/frame 0xfe1247ee5bf0
 Xfast_syscall() at Xfast_syscall+0xfb/frame 0xfe1247ee5bf0
 --- syscall (22, FreeBSD ELF64, sys_unmount), rip = 0x8008a02fa, rsp = 
0x7fffd198, rbp = 0x7fffd2b0 ---
 Uptime: 44m40s

 (kgdb) #0  doadump (textdump=1) at pcpu.h:219
 #1  0x808bcf87 in kern_reboot (howto=260)
 at /usr/src/sys/kern/kern_shutdown.c:447
 #2  0x808bd495 in vpanic (fmt=value optimized out,
 ap=value optimized out) at /usr/src/sys/kern/kern_shutdown.c:754
 #3  0x808bd326 in kassert_panic (fmt=value optimized out)
 at /usr/src/sys/kern/kern_shutdown.c:642
 #4  0x81e159d3 in tmpfs_unmount (mp=0xf810502cd660,
 mntflags=value optimized out)
 at /usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_vfsops.c:316
 #5  0x8095e1af in dounmount (mp=0xf810502cd660, flags=134742016,
 td=0xf8013d57a490) at /usr/src/sys/kern/vfs_mount.c:1324
 #6  0x8095dd66 in sys_unmount (td=0xf8013d57a490,
 uap=0xfe1247ee5b80) at /usr/src/sys/kern/vfs_mount.c:1212
 #7  0x80cb7d75 in amd64_syscall (td=0xf8013d57a490, traced=0)
 at subr_syscall.c:134
 #8  0x80c9c90b in Xfast_syscall ()
 at /usr/src/sys/amd64/amd64/exception.S:391
 #9  0x0008008a02fa in ?? ()


Do you have core ?
I want to see the struct tmpfs_mount content for the tmpfs mount point
which caused the panic.


Yes.

Hopefully this is what you're asking for:

(kgdb) frame
#4  0x81e159d3 in tmpfs_unmount (mp=0xf810502cd660, 
mntflags=value optimized out) at 
/usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_vfsops.c:316

316 MPASS(tmp-tm_pages_used == 0);

(kgdb) print *mp
$2 = {mnt_mtx = {lock_object = {lo_name = 0x80f11f09 struct 
mount mtx, lo_flags = 16973824, lo_data = 0, lo_witness = 
0xfe6d3b00}, mtx_lock = 4}, mnt_gen = 1, mnt_list = {tqe_next = 
0xf8116be06660, tqe_prev = 0xf81050257688}, mnt_op = 
0x81e1b940, mnt_vfc = 0x81e1ba60, mnt_vnodecovered = 
0xf8104fb0c3b0,
  mnt_syncer = 0x0, mnt_ref = 1, mnt_nvnodelist = {tqh_first = 0x0, 
tqh_last = 0xf810502cd6c0}, mnt_nvnodelistsize = 0, 
mnt_activevnodelist = {tqh_first = 0x0, tqh_last = 0xf810502cd6d8}, 
mnt_activevnodelistsize = 0, mnt_writeopcount = 1, mnt_kern_flag = 
16777225, mnt_flag = 4096, mnt_opt = 0xf80014424ae0, mnt_optnew = 
0x0, mnt_maxsymlinklen = 0,
  mnt_stat = {f_version = 537068824, f_type = 135, f_flags = 4096, 
f_bsize = 4096, f_iosize = 4096, f_blocks = 17125058, f_bfree = 
17049291, f_bavail = 17049291, f_files = 2147483647, f_ffree = 
2147473906, f_syncwrites = 0, f_asyncwrites = 0, f_syncreads = 0, 
f_asyncreads = 0, f_spare = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, f_namemax = 
255, f_owner = 0, f_fsid = {
  val = {-2029977679, 135}}, f_charspare = '\0' repeats 79 times, 
f_fstypename = tmpfs\000\000\000\000\000\000\000\000\000\000, 
f_mntfromname = tmpfs, '\0' repeats 82 times, f_mntonname = 
/poudriere/data/build/exp-91amd64-default-xzibition/08/usr/local, '\0' 
repeats 23 times}, mnt_cred = 0xf8001418e100, mnt_data = 
0xf80fedf75700,
  mnt_time = 0, mnt_iosize_max = 65536, mnt_export = 0x0, mnt_label = 
0x0, mnt_hashseed = 4132690418, mnt_lockref = 0, mnt_secondary_writes = 
0, mnt_secondary_accwrites = 0, mnt_susp_owner = 0x0, mnt_gjprovider = 
0x0, mnt_explock = {lock_object = {lo_name = 0x80f11f1a 
explock, lo_flags = 108199936, lo_data = 0, lo_witness = 
0xfe6eb280},
lk_lock = 1, lk_exslpfail = 0, lk_timo = 0, lk_pri = 96}, 
mnt_upper_link = {tqe_next = 0x0, tqe_prev = 0x0}, mnt_uppers = 
{tqh_first = 0x0, tqh_last = 0xf810502cd980}}


(kgdb) print *(struct tmpfs_mount *)(mp)-mnt_data
$3 = {tm_pages_max = 18446744073709551615, tm_pages_used = 
18446744073709551615, tm_root = 0xf8104ff44828, tm_nodes_max = 
2147483647, tm_ino_unr = 0xf8002fd65080, tm_nodes_inuse = 0, 
tm_maxfilesize = 9223372036854775807, tm_nodes_used = {lh_first = 0x0}, 
allnode_lock = {lock_object = {lo_name = 0x81e1aa47 tmpfs 
allnode lock,
 

Re: (r257598) panic: Assertion tmp-tm_pages_used == 0 failed at /usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_vfsops.c:316

2013-11-04 Thread Konstantin Belousov
On Mon, Nov 04, 2013 at 10:43:06AM -0600, Bryan Drewery wrote:
 On 2013-11-04 10:27, Konstantin Belousov wrote:
  On Mon, Nov 04, 2013 at 08:35:17AM -0600, Bryan Drewery wrote:
  11.0-CURRENT #87 r257598
  
  During a poudriere build.
  
  It creates a tmpfs, builds a port in a jail using that tmpfs and then
  removes the tmpfs and recreate the tmpfs before building the next 
  port.
  
   panic: Assertion tmp-tm_pages_used == 0 failed at 
   /usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_vfsops.c:316
   cpuid = 9
   KDB: stack backtrace:
   db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 
   0xfe1247ee57a0
   kdb_backtrace() at kdb_backtrace+0x39/frame 0xfe1247ee5850
   vpanic() at vpanic+0x126/frame 0xfe1247ee5890
   kassert_panic() at kassert_panic+0x136/frame 0xfe1247ee5900
   tmpfs_unmount() at tmpfs_unmount+0x163/frame 0xfe1247ee5930
   dounmount() at dounmount+0x41f/frame 0xfe1247ee59b0
   sys_unmount() at sys_unmount+0x356/frame 0xfe1247ee5ae0
   amd64_syscall() at amd64_syscall+0x265/frame 0xfe1247ee5bf0
   Xfast_syscall() at Xfast_syscall+0xfb/frame 0xfe1247ee5bf0
   --- syscall (22, FreeBSD ELF64, sys_unmount), rip = 0x8008a02fa, rsp = 
   0x7fffd198, rbp = 0x7fffd2b0 ---
   Uptime: 44m40s
  
   (kgdb) #0  doadump (textdump=1) at pcpu.h:219
   #1  0x808bcf87 in kern_reboot (howto=260)
   at /usr/src/sys/kern/kern_shutdown.c:447
   #2  0x808bd495 in vpanic (fmt=value optimized out,
   ap=value optimized out) at /usr/src/sys/kern/kern_shutdown.c:754
   #3  0x808bd326 in kassert_panic (fmt=value optimized out)
   at /usr/src/sys/kern/kern_shutdown.c:642
   #4  0x81e159d3 in tmpfs_unmount (mp=0xf810502cd660,
   mntflags=value optimized out)
   at /usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_vfsops.c:316
   #5  0x8095e1af in dounmount (mp=0xf810502cd660, 
   flags=134742016,
   td=0xf8013d57a490) at /usr/src/sys/kern/vfs_mount.c:1324
   #6  0x8095dd66 in sys_unmount (td=0xf8013d57a490,
   uap=0xfe1247ee5b80) at /usr/src/sys/kern/vfs_mount.c:1212
   #7  0x80cb7d75 in amd64_syscall (td=0xf8013d57a490, traced=0)
   at subr_syscall.c:134
   #8  0x80c9c90b in Xfast_syscall ()
   at /usr/src/sys/amd64/amd64/exception.S:391
   #9  0x0008008a02fa in ?? ()
  
  Do you have core ?
  I want to see the struct tmpfs_mount content for the tmpfs mount point
  which caused the panic.
 
 Yes.
 
 Hopefully this is what you're asking for:
 
 (kgdb) frame
 #4  0x81e159d3 in tmpfs_unmount (mp=0xf810502cd660, 
 mntflags=value optimized out) at 
 /usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_vfsops.c:316
 316 MPASS(tmp-tm_pages_used == 0);
 
 (kgdb) print *mp
 $2 = {mnt_mtx = {lock_object = {lo_name = 0x80f11f09 struct 
 mount mtx, lo_flags = 16973824, lo_data = 0, lo_witness = 
 0xfe6d3b00}, mtx_lock = 4}, mnt_gen = 1, mnt_list = {tqe_next = 
 0xf8116be06660, tqe_prev = 0xf81050257688}, mnt_op = 
 0x81e1b940, mnt_vfc = 0x81e1ba60, mnt_vnodecovered = 
 0xf8104fb0c3b0,
mnt_syncer = 0x0, mnt_ref = 1, mnt_nvnodelist = {tqh_first = 0x0, 
 tqh_last = 0xf810502cd6c0}, mnt_nvnodelistsize = 0, 
 mnt_activevnodelist = {tqh_first = 0x0, tqh_last = 0xf810502cd6d8}, 
 mnt_activevnodelistsize = 0, mnt_writeopcount = 1, mnt_kern_flag = 
 16777225, mnt_flag = 4096, mnt_opt = 0xf80014424ae0, mnt_optnew = 
 0x0, mnt_maxsymlinklen = 0,
mnt_stat = {f_version = 537068824, f_type = 135, f_flags = 4096, 
 f_bsize = 4096, f_iosize = 4096, f_blocks = 17125058, f_bfree = 
 17049291, f_bavail = 17049291, f_files = 2147483647, f_ffree = 
 2147473906, f_syncwrites = 0, f_asyncwrites = 0, f_syncreads = 0, 
 f_asyncreads = 0, f_spare = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, f_namemax = 
 255, f_owner = 0, f_fsid = {
val = {-2029977679, 135}}, f_charspare = '\0' repeats 79 times, 
 f_fstypename = tmpfs\000\000\000\000\000\000\000\000\000\000, 
 f_mntfromname = tmpfs, '\0' repeats 82 times, f_mntonname = 
 /poudriere/data/build/exp-91amd64-default-xzibition/08/usr/local, '\0' 
 repeats 23 times}, mnt_cred = 0xf8001418e100, mnt_data = 
 0xf80fedf75700,
mnt_time = 0, mnt_iosize_max = 65536, mnt_export = 0x0, mnt_label = 
 0x0, mnt_hashseed = 4132690418, mnt_lockref = 0, mnt_secondary_writes = 
 0, mnt_secondary_accwrites = 0, mnt_susp_owner = 0x0, mnt_gjprovider = 
 0x0, mnt_explock = {lock_object = {lo_name = 0x80f11f1a 
 explock, lo_flags = 108199936, lo_data = 0, lo_witness = 
 0xfe6eb280},
  lk_lock = 1, lk_exslpfail = 0, lk_timo = 0, lk_pri = 96}, 
 mnt_upper_link = {tqe_next = 0x0, tqe_prev = 0x0}, mnt_uppers = 
 {tqh_first = 0x0, tqh_last = 0xf810502cd980}}
 
 (kgdb) print *(struct tmpfs_mount *)(mp)-mnt_data
 $3 = {tm_pages_max = 18446744073709551615, tm_pages_used = 
 18446744073709551615, tm_root = 0xf8104ff44828, tm_nodes_max = 
 

Re: (r257598) panic: Assertion tmp-tm_pages_used == 0 failed at /usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_vfsops.c:316

2013-11-04 Thread Bryan Drewery

On 2013-11-04 11:27, Konstantin Belousov wrote:

On Mon, Nov 04, 2013 at 10:43:06AM -0600, Bryan Drewery wrote:

On 2013-11-04 10:27, Konstantin Belousov wrote:
 On Mon, Nov 04, 2013 at 08:35:17AM -0600, Bryan Drewery wrote:
 11.0-CURRENT #87 r257598

 During a poudriere build.

 It creates a tmpfs, builds a port in a jail using that tmpfs and then
 removes the tmpfs and recreate the tmpfs before building the next
 port.

  panic: Assertion tmp-tm_pages_used == 0 failed at 
/usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_vfsops.c:316
  cpuid = 9
  KDB: stack backtrace:
  db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 
0xfe1247ee57a0
  kdb_backtrace() at kdb_backtrace+0x39/frame 0xfe1247ee5850
  vpanic() at vpanic+0x126/frame 0xfe1247ee5890
  kassert_panic() at kassert_panic+0x136/frame 0xfe1247ee5900
  tmpfs_unmount() at tmpfs_unmount+0x163/frame 0xfe1247ee5930
  dounmount() at dounmount+0x41f/frame 0xfe1247ee59b0
  sys_unmount() at sys_unmount+0x356/frame 0xfe1247ee5ae0
  amd64_syscall() at amd64_syscall+0x265/frame 0xfe1247ee5bf0
  Xfast_syscall() at Xfast_syscall+0xfb/frame 0xfe1247ee5bf0
  --- syscall (22, FreeBSD ELF64, sys_unmount), rip = 0x8008a02fa, rsp = 
0x7fffd198, rbp = 0x7fffd2b0 ---
  Uptime: 44m40s

  (kgdb) #0  doadump (textdump=1) at pcpu.h:219
  #1  0x808bcf87 in kern_reboot (howto=260)
  at /usr/src/sys/kern/kern_shutdown.c:447
  #2  0x808bd495 in vpanic (fmt=value optimized out,
  ap=value optimized out) at /usr/src/sys/kern/kern_shutdown.c:754
  #3  0x808bd326 in kassert_panic (fmt=value optimized out)
  at /usr/src/sys/kern/kern_shutdown.c:642
  #4  0x81e159d3 in tmpfs_unmount (mp=0xf810502cd660,
  mntflags=value optimized out)
  at /usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_vfsops.c:316
  #5  0x8095e1af in dounmount (mp=0xf810502cd660, 
flags=134742016,
  td=0xf8013d57a490) at /usr/src/sys/kern/vfs_mount.c:1324
  #6  0x8095dd66 in sys_unmount (td=0xf8013d57a490,
  uap=0xfe1247ee5b80) at /usr/src/sys/kern/vfs_mount.c:1212
  #7  0x80cb7d75 in amd64_syscall (td=0xf8013d57a490, traced=0)
  at subr_syscall.c:134
  #8  0x80c9c90b in Xfast_syscall ()
  at /usr/src/sys/amd64/amd64/exception.S:391
  #9  0x0008008a02fa in ?? ()

 Do you have core ?
 I want to see the struct tmpfs_mount content for the tmpfs mount point
 which caused the panic.

Yes.

Hopefully this is what you're asking for:

(kgdb) frame
#4  0x81e159d3 in tmpfs_unmount (mp=0xf810502cd660,
mntflags=value optimized out) at
/usr/src/sys/modules/tmpfs/../../fs/tmpfs/tmpfs_vfsops.c:316
316 MPASS(tmp-tm_pages_used == 0);

(kgdb) print *mp
$2 = {mnt_mtx = {lock_object = {lo_name = 0x80f11f09 struct
mount mtx, lo_flags = 16973824, lo_data = 0, lo_witness =
0xfe6d3b00}, mtx_lock = 4}, mnt_gen = 1, mnt_list = {tqe_next 
=

0xf8116be06660, tqe_prev = 0xf81050257688}, mnt_op =
0x81e1b940, mnt_vfc = 0x81e1ba60, mnt_vnodecovered =
0xf8104fb0c3b0,
   mnt_syncer = 0x0, mnt_ref = 1, mnt_nvnodelist = {tqh_first = 0x0,
tqh_last = 0xf810502cd6c0}, mnt_nvnodelistsize = 0,
mnt_activevnodelist = {tqh_first = 0x0, tqh_last = 
0xf810502cd6d8},

mnt_activevnodelistsize = 0, mnt_writeopcount = 1, mnt_kern_flag =
16777225, mnt_flag = 4096, mnt_opt = 0xf80014424ae0, mnt_optnew =
0x0, mnt_maxsymlinklen = 0,
   mnt_stat = {f_version = 537068824, f_type = 135, f_flags = 4096,
f_bsize = 4096, f_iosize = 4096, f_blocks = 17125058, f_bfree =
17049291, f_bavail = 17049291, f_files = 2147483647, f_ffree =
2147473906, f_syncwrites = 0, f_asyncwrites = 0, f_syncreads = 0,
f_asyncreads = 0, f_spare = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, f_namemax 
=

255, f_owner = 0, f_fsid = {
   val = {-2029977679, 135}}, f_charspare = '\0' repeats 79 
times,

f_fstypename = tmpfs\000\000\000\000\000\000\000\000\000\000,
f_mntfromname = tmpfs, '\0' repeats 82 times, f_mntonname =
/poudriere/data/build/exp-91amd64-default-xzibition/08/usr/local, 
'\0'

repeats 23 times}, mnt_cred = 0xf8001418e100, mnt_data =
0xf80fedf75700,
   mnt_time = 0, mnt_iosize_max = 65536, mnt_export = 0x0, mnt_label =
0x0, mnt_hashseed = 4132690418, mnt_lockref = 0, mnt_secondary_writes 
=

0, mnt_secondary_accwrites = 0, mnt_susp_owner = 0x0, mnt_gjprovider =
0x0, mnt_explock = {lock_object = {lo_name = 0x80f11f1a
explock, lo_flags = 108199936, lo_data = 0, lo_witness =
0xfe6eb280},
 lk_lock = 1, lk_exslpfail = 0, lk_timo = 0, lk_pri = 96},
mnt_upper_link = {tqe_next = 0x0, tqe_prev = 0x0}, mnt_uppers =
{tqh_first = 0x0, tqh_last = 0xf810502cd980}}

(kgdb) print *(struct tmpfs_mount *)(mp)-mnt_data
$3 = {tm_pages_max = 18446744073709551615, tm_pages_used =
18446744073709551615, tm_root = 0xf8104ff44828, tm_nodes_max =
2147483647, tm_ino_unr = 0xf8002fd65080, tm_nodes_inuse = 0,
tm_maxfilesize =