bug#13103: 24.3.50; Trunk --with-ns eats 100% CPU

[Didier Verna]

Eli Zaretskii <eliz@gnu.org> wrote:

>> From: Didier Verna <didier@didierverna.net>
>> Date: Thu, 06 Dec 2012 14:41:03 +0100
>> 
>> the Emacs trunk eats 100% CPU on one of my cores at startup, when
>> compiled --with-ns.
>
> When this happens, please attach a debugger to Emacs and show us where
> it loops.  There's some guidance in etc/DEBUG regarding this; search
> for "Emacs fails to respond".

  Here's the result of gdb's 'where' when I kill -TSTP the Emacs.app
  process, after attaching GDB to it. Not sure that's very useful. Also,
  I should point out that Emacs itself does NOT hang or become
  unresponsive. It works like a charm. It's just that the CPU usage goes
  way up.



#0  0x00007fff838dfd7a in mach_msg_trap ()
#1  0x00007fff838e0444 in mach_msg ()
#2  0x00007fff89580902 in __CFRunLoopRun ()
#3  0x00007fff8957fd8f in CFRunLoopRunSpecific ()
#4  0x00007fff809507ee in RunCurrentEventLoopInMode ()
#5  0x00007fff809505f3 in ReceiveNextEventCommon ()
#6  0x00007fff809504ac in BlockUntilNextEventMatchingListInMode ()
#7  0x00007fff83ae4eb2 in _DPSNextEvent ()
#8  0x00007fff83ae4801 in -[NSApplication 
nextEventMatchingMask:untilDate:inMode:dequeue:] ()
#9  0x00007fff83aaa68f in -[NSApplication run] ()
#10 0x0000000100191d95 in ns_select (nfds=1, readfds=0x7fff5fbfa290, 
writefds=0x7fff5fbfa210, exceptfds=<value temporarily unavailable, due to 
optimizations>, timeout=0x7fff5fbfa330, sigmask=<value temporarily unavailable, 
due to optimizations>) at /usr/local/src/emacs/trunk/src/nsterm.m:3537
#11 0x000000010015dfad in wait_reading_process_output (time_limit=<value 
temporarily unavailable, due to optimizations>, nsecs=0, read_kbd               
                                                                                
       #12 0x00000001000ac645 in read_char (commandflag=1, nmaps=2, 
maps=0x7fff5fbfa790, prev_event=<value temporarily unavailable, due to 
optimizations>, used_mouse_menu=0x7fff5fbfa9b7, end_time=0x0) at 
/usr/local/src/emacs/trunk/src/keyboard.c:3784
#13 0x00000001000aed5d in read_key_sequence (keybuf=0x7fff5fbfaa70, bufsize=30, 
prompt=4320145466, dont_downcase_last                                           
#14 0x00000001000b0e3a in command_loop_1 () at 
/usr/local/src/emacs/trunk/src/keyboard.c:1448
#15 0x0000000100117ea5 in internal_condition_case (bfun=0x1000b0be0 
<command_loop_1>, handlers=4320211706, hfun=0x1000a91a0 <cmd_error>) at 
/usr/local/src/emacs/trunk/src/eval.c:1192
#16 0x00000001000a6e67 in command_loop_2 (ignore=<value temporarily 
unavailable, due to optimizations>) at 
/usr/local/src/emacs/trunk/src/keyboard.c:1163
#17 0x0000000100117fae in internal_catch (tag=<value temporarily unavailable, 
due to optimizations>, func=0x1000a6e30 <command_loop_2>, arg=4320145466) at 
/usr/local/src/emacs/trunk/src/eval.c:963
#18 0x00000001000a752c in recursive_edit_1 () at 
/usr/local/src/emacs/trunk/src/keyboard.c:1142
#19 0x00000001000a94d3 in Frecursive_edit () at 
/usr/local/src/emacs/trunk/src/keyboard.c:838
#20 0x000000010009f77e in main (argc=2, argv=0x7fff5fbfb038) at 
/usr/local/src/emacs/trunk/src/emacs.c:1560

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