Re: shutdown freeze and forced unmounts

[Joe Talbott <josepht@xxxxxxxxxx>]

On Thu, Jun 28, 2007 at 12:09:09PM -0700, Matthew Dillon wrote:
> 
> :I'm seeing the same behavior with my vkernel-mp work.  Often the
> :vkernel hangs and is unkillable leaving the processes around until I
> :reboot and I see these messages.  I haven't seen them otherwise and
> :rebooting succeeds without intervention.
> :
> :Joe
> 
>     You should always be able to kill -9 a vkernel.  Can you gdb it when
>     it is in that state?

I run it from gdb to start with and when I try to kill it via gdb it
hangs.  

Program received signal SIGQUIT, Quit.
0x282c5858 in sigsuspend () from /usr/lib/libc.so.6
(gdb) bt
#0  0x282c5858 in sigsuspend () from /usr/lib/libc.so.6
#1  0x282766a8 in _sigsuspend (set=0x0)
    at
/home/josepht/src/vksrc.cvs.2/lib/libthread_xu/thread/thr_sig.c:202
#2  0x282c285c in sigpause () from /usr/lib/libc.so.6
#3  0x08203ee5 in cpu_idle ()
    at
/home/josepht/src/vksrc/sys/platform/vkernel/i386/cpu_regs.c:707
#4  0x00000000 in ?? ()
(gdb) k
Kill the program being debugged? (y or n) y

^^^ nothing

Here's what I see in kgdb:

* 50 Thread 0xdd919e00 (PID=13027: kernel.debug)  lwkt_switch ()
    at thread2.h:177
  49 Thread 0xd688c600 (PID=13027: kernel.debug)  lwkt_switch ()
    at thread2.h:177

(kgdb) thread 50
[Switching to thread 50 (Thread 0xdd919e00)]#0  lwkt_switch () at
thread2.h:177
177         globaldata_t gd = curtd->td_gd;
(kgdb) bt
#0  lwkt_switch () at thread2.h:177
#1  0xc020c4b1 in tsleep (ident=0xd68a9ac0, flags=256, 
    wmesg=0xc0429363 "pause", timo=0)
    at /home/josepht/src/vksrc.cvs.2/sys/kern/kern_synch.c:473
#2  0xc01ffb51 in kern_sigsuspend (set=0x0)
    at /home/josepht/src/vksrc.cvs.2/sys/kern/kern_sig.c:551
#3  0xc01ffb94 in sys_sigsuspend (uap=0x0)
    at /home/josepht/src/vksrc.cvs.2/sys/kern/kern_sig.c:571
#4  0xc03db1a8 in syscall2 (frame=0xdd996d40)
    at
/home/josepht/src/vksrc.cvs.2/sys/platform/pc32/i386/trap.c:1340
#5  0xc03c2b55 in Xint0x80_syscall ()
    at
/home/josepht/src/vksrc.cvs.2/sys/platform/pc32/i386/exception.s:872
#6  0x282c5858 in ?? ()
#7  0x41007cf0 in ?? ()
#8  0x0000002f in ?? ()
#9  0x00000000 in ?? ()
#10 0x00000000 in ?? ()
#11 0x00000000 in ?? ()
#12 0x00000000 in ?? ()
#13 0x14d81000 in ?? ()
#14 0xff800000 in ?? ()
#15 0xdd919e00 in ?? ()
#16 0xdd996bcc in ?? ()
#17 0xdd996b9c in ?? ()
#18 0xdd918600 in ?? ()
#19 0xc0207152 in lwkt_switch ()
    at /home/josepht/src/vksrc.cvs.2/sys/kern/lwkt_thread.c:749
Previous frame inner to this frame (corrupt stack?)

Joe