bug#8157: mode related?

[Eli Zaretskii <eliz@gnu.org>]

> From: Tony An <Anthony.An@sas.com>
> CC: "8157@debbugs.gnu.org" <8157@debbugs.gnu.org>
> Date: Thu, 3 Mar 2011 19:24:08 +0000
> Accept-Language: en-US
> 
> I can run Emacs under GDB, although I am not sure what I am supposed to look at under it. 

See below.

> I wasn't sure this will helps even it was hanging like yesterday because I was unable to do anything at all in Emacs when it was hung.  Now, it's not hanging, would this GDB helps to identify something unusual? 

No, not really.  You need to wait until it appears to hang again.
When it does, try attaching GDB to the Emacs process.  If that works
and you get the GDB prompt, type "bt" to see where Emacs hangs.

If you don't get the GDB prompt, try typing "kill -TSTP <pid>" from
the shell prompt, where <pid> is the Emacs process ID.  You should be
able to get Emacs interrupted, GDB should gain control, and you can
type "bt".

There's more advice and tricks under "If the symptom of the bug is
that Emacs fails to respond" in the file etc/DEBUG that you should be
able to find in your Emacs tree.