XCreateFontSet called for each X window emacs frame is heavy

[Alexander Kotelnikov]

Hello.

I think it is years now since I had noticed that every new emacs frame
either first or any subsequent makes all my computers feel bad. X
display stands still, cursor moves, but does not respond to clicks,
focus switches slowly. This continues of a split second, but it
hurts, I assure you. I do not know any other program, that causes
such problems.

Today I performed the following steps:
1. Checked that this feature is reproducible with emacs-snapshot from
   Debian/unstable.
2. Got emacs21 sources, built them and started emacs in debugger.

Here is the place the trouble occurs:
Breakpoint 15, create_frame_xic (f=0x849a8c0) at xfns.c:3348
3348    {
(gdb) cont
Continuing.

Breakpoint 17, xic_create_xfontset (f=0x849a8c0, 
    base_fontname=0xbfdbc270 "-*-*-medium-r-normal--13-*-*-*-*-*-*-*") at 
xfns.c:3310
3310      xfs = XCreateFontSet (FRAME_X_DISPLAY (f),

I suppose really a lot of fonts match this pattern.

Let's think, if something can be done to improve the situation.

Thank you for your attention

backtrace:
#0  xic_create_xfontset (f=<value optimized out>, base_fontname=<value 
optimized out>)
    at xfns.c:3318
#1  0x080c876a in create_frame_xic (f=0x849a8c0) at xfns.c:3408
#2  0x080ca834 in x_window (f=0x849a8c0) at xfns.c:3842
#3  0x080cee1a in Fx_create_frame (parms=1480533300) at xfns.c:4433
#4  0x08135684 in Ffuncall (nargs=2, args=0xbfdbc488) at eval.c:2659
#5  0x08161790 in Fbyte_code (bytestr=941887248, vector=1210322784, maxdepth=5)
    at bytecode.c:716
#6  0x081351c4 in funcall_lambda (fun=1210322660, nargs=1, 
arg_vector=0xbfdbc5b4)
    at eval.c:2851
#7  0x081355a6 in Ffuncall (nargs=2, args=0xbfdbc5b0) at eval.c:2716
#8  0x08161790 in Fbyte_code (bytestr=941841804, vector=1210277296, maxdepth=3)
    at bytecode.c:716
#9  0x081351c4 in funcall_lambda (fun=1210277212, nargs=1, 
arg_vector=0xbfdbc6d4)
    at eval.c:2851
#10 0x081355a6 in Ffuncall (nargs=2, args=0xbfdbc6d0) at eval.c:2716
#11 0x08161790 in Fbyte_code (bytestr=941838140, vector=1210273700, maxdepth=4)
    at bytecode.c:716
#12 0x081351c4 in funcall_lambda (fun=1210273568, nargs=0, 
arg_vector=0xbfdbc7f4)
    at eval.c:2851
#13 0x081355a6 in Ffuncall (nargs=1, args=0xbfdbc7f0) at eval.c:2716
#14 0x08161790 in Fbyte_code (bytestr=941992740, vector=1210429452, maxdepth=5)
    at bytecode.c:716
#15 0x081351c4 in funcall_lambda (fun=1210428172, nargs=0, 
arg_vector=0xbfdbc924)
    at eval.c:2851
#16 0x081355a6 in Ffuncall (nargs=1, args=0xbfdbc920) at eval.c:2716
#17 0x08161790 in Fbyte_code (bytestr=941988804, vector=1210424404, maxdepth=5)
    at bytecode.c:716
#18 0x081351c4 in funcall_lambda (fun=1210424236, nargs=0, 
arg_vector=0xbfdbc9f0)
    at eval.c:2851
#19 0x081353c4 in apply_lambda (fun=1210424236, args=405279788, eval_flag=1)
    at eval.c:2770
#20 0x0813469a in Feval (form=1480204196) at eval.c:2071
#21 0x080dd753 in top_level_2 () at keyboard.c:1254
#22 0x081341bf in internal_condition_case (bfun=0x80dd740 <top_level_2>, 
    handlers=405376132, hfun=0x80dfdc0 <cmd_error>) at eval.c:1267
#23 0x080df8f1 in top_level_1 () at keyboard.c:1262
#24 0x08134274 in internal_catch (tag=405337716, func=0x80df8c0 <top_level_1>, 
    arg=405279788) at eval.c:1030
#25 0x080dfa8a in command_loop () at keyboard.c:1223
#26 0x080dfb5b in recursive_edit_1 () at keyboard.c:950
#27 0x080dfc83 in Frecursive_edit () at keyboard.c:1006
#28 0x080d7f02 in main (argc=1, argv=0xbfdbd144, envp=0x0) at emacs.c:1547

-- 
Alexander Kotelnikov
Saint-Petersburg, Russia