Re: Debugging M-x gdb

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sun, 26 Mar 2023 20:09:31 +0200
> From:  Manuel Giraud via "Emacs development discussions." <emacs-devel@gnu.org>
> I don't know if I should file a bug report for this so I'm trying here.
> 
> Whenever I try to debug Emacs with M-x gdb, I see the following
> behaviour.  In the *gud-emacs* buffer, I enter "set args -Q" and then
> "run"... then I exit the debugged Emacs and now the Emacs from where I
> called (gdb) starts taking a full CPU.  I had to enter "quit" into the
> *gud-emacs* buffer to stop this (return to normal CPU usage).
> 
> I'd really like to debug this issue but don't really where to start.  I
> have tried to profile-start/profile-report but I don't get much clue out
> of it.  How could I proceed?

Are you sure it's Emacs that consumes high CPU, and not GDB? what does
'top' or similar command says about which process consumes CPU?

If it's indeed Emacs, then when Emacs starts consuming high CPU,
attach GDB to it, then type this:

  (gdb) source /path/to/emacs/src/.gdbinit
  (gdb) thread apply all bt

and post everything this produces with a bug report sent via
report-emacs-bug.

Thanks.

P.S. In which Emacs version does that happen, and with which version
of GDB?