On 28-Nov-00 Andrea Campi wrote:
> Latest (this night) current, no system activity:
> panic: mutex Giant owned at ../../kern/kern_intr.c:238
> I can sen you kernel conf if needed.
> Is this known or should I invest some time to debug it?

Eek!  I haven't seen this.  If you can reproduce this, stick DDB, WITNESS, and
MUTEX_DEBUG in your kernel.  Then when you get to the ddb prompt, do a
'x __mtx_debug_Giant' followed by 'x/x,8 __mtx_debug_Giant' (to work around
weird bugs in ddb).  The last commad is a dump of Giant's mtx_debug structure:

struct mtx_debug {
        struct witness  *mtxd_witness;
        LIST_ENTRY(mtx) mtxd_held;
        const char      *mtxd_file;
        int             mtxd_line;
        const char      *mtxd_description;

We want mtxd_file and mtxd_line.  If you look at the output of the last
command, it will probably look something like this:

db> x/x,8 __mtx_debug_Giant
__mtx_debug_Giant:      c03303d8        0               cb6475ac  c02fdd2a
__mtx_debug_Giant+0x10: da              c02f97ad        0         0

The last number of the first line is the address of the string holding the

db> x/s 0xc02fdd2a
__set_sysinit_set_sym...: ../../i386/isa/ithread.c

The first number on the second line is the line number:

db> x/d __mtx_debug_Giant+0x10
__mtx_debug_Giant+0x10: 218

So in this case Giant was last acquired at line 218 of ../../i386/isa/ithread.c.

Finding out where Giant was last obtained will help with finding out where it
was supposed to be dropped but wasn't.

> Bye,
>       Andrea


John Baldwin <[EMAIL PROTECTED]> -- http://www.FreeBSD.org/~jhb/
PGP Key: http://www.baldwin.cx/~john/pgpkey.asc
"Power Users Use the Power to Serve!"  -  http://www.FreeBSD.org/

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