I've been working with my setup lately and have been trying to determine where my 2.3s terminal load times have been coming from. I'm fairly new to linux performance testing in general but I have determined a few things.
The first thing I should mention is that terminal is a shell program with the following:
#!/bin/sh
WINIT_X11_SCALE_FACTOR=1.5 alacritty "$@"
The stats on launching the terminal program (alacritty) and its shell (zsh -l):
> perf stat -r 10 -d terminal -e $SHELL -slc exit
Performance counter stats for 'terminal -e /usr/bin/zsh -slc exit' (10 runs):
602.55 msec task-clock # 0.261 CPUs utilized ( +- 1.33% )
957 context-switches # 1.532 K/sec ( +- 0.42% )
92 cpu-migrations # 147.298 /sec ( +- 1.89% )
68,150 page-faults # 109.113 K/sec ( +- 0.13% )
2,188,445,151 cycles # 3.504 GHz ( +- 0.17% )
3,695,337,515 instructions # 1.70 insn per cycle ( +- 0.08% )
791,333,786 branches # 1.267 G/sec ( +- 0.06% )
14,007,258 branch-misses # 1.78% of all branches ( +- 0.09% )
10,893,173,535 slots # 17.441 G/sec ( +- 0.13% )
3,574,546,556 topdown-retiring # 30.5% Retiring ( +- 0.11% )
2,888,937,632 topdown-bad-spec # 24.0% Bad Speculation ( +- 0.41% )
3,125,577,758 topdown-fe-bound # 27.1% Frontend Bound ( +- 0.16% )
2,189,183,796 topdown-be-bound # 18.4% Backend Bound ( +- 0.47% )
924,852,782 L1-dcache-loads # 1.481 G/sec ( +- 0.07% )
38,308,478 L1-dcache-load-misses # 4.16% of all L1-dcache accesses ( +- 0.09% )
3,445,566 LLC-loads # 5.517 M/sec ( +- 0.20% )
725,990 LLC-load-misses # 20.97% of all LL-cache accesses ( +- 0.36% )
2.30683 +- 0.00331 seconds time elapsed ( +- 0.14% )
The stats on launching just the shell (zsh):
Performance counter stats for '/usr/bin/zsh -i -c exit' (10 runs):
1,548.56 msec task-clock # 0.987 CPUs utilized ( +- 3.28% )
525 context-switches # 323.233 /sec ( +- 21.17% )
16 cpu-migrations # 9.851 /sec ( +- 11.33% )
90,616 page-faults # 55.791 K/sec ( +- 2.63% )
6,559,830,564 cycles # 4.039 GHz ( +- 3.18% )
11,317,955,247 instructions # 1.68 insn per cycle ( +- 3.69% )
2,351,473,571 branches # 1.448 G/sec ( +- 3.46% )
46,539,165 branch-misses # 1.91% of all branches ( +- 1.31% )
32,783,001,655 slots # 20.184 G/sec ( +- 3.18% )
10,776,867,769 topdown-retiring # 32.5% Retiring ( +- 3.28% )
5,729,353,491 topdown-bad-spec # 18.2% Bad Speculation ( +- 6.90% )
11,083,567,578 topdown-fe-bound # 33.3% Frontend Bound ( +- 2.34% )
5,458,201,823 topdown-be-bound # 15.9% Backend Bound ( +- 4.51% )
3,180,211,376 L1-dcache-loads # 1.958 G/sec ( +- 3.10% )
126,282,947 L1-dcache-load-misses # 3.85% of all L1-dcache accesses ( +- 2.37% )
14,347,257 LLC-loads # 8.833 M/sec ( +- 1.48% )
2,386,047 LLC-load-misses # 16.33% of all LL-cache accesses ( +- 0.77% )
1.5682 +- 0.0550 seconds time elapsed ( +- 3.51% )
The stats on launching the shell (zsh) with zmodload zsh/zprof:
num calls time self name
-----------------------------------------------------------------------------------
1) 31 78.54 2.53 77.09% 50.07 1.62 49.14% antigen
2) 2 23.24 11.62 22.81% 15.93 7.96 15.63% compinit
3) 2 7.31 3.66 7.18% 7.31 3.66 7.18% compaudit
4) 1 8.27 8.27 8.12% 7.29 7.29 7.16% _autoenv_source
5) 1 6.93 6.93 6.80% 6.93 6.93 6.80% detect-clipboard
6) 1 5.18 5.18 5.08% 5.18 5.18 5.08% _autoenv_hash_pair
7) 1 2.49 2.49 2.45% 2.45 2.45 2.41% _zsh_highlight_load_highlighters
8) 2 1.01 0.51 0.99% 1.01 0.51 0.99% _autoenv_stack_entered_contains
9) 10 0.91 0.09 0.89% 0.91 0.09 0.89% add-zsh-hook
10) 1 0.94 0.94 0.92% 0.87 0.87 0.85% _autoenv_stack_entered_add
11) 1 0.85 0.85 0.84% 0.85 0.85 0.84% async_init
12) 1 0.49 0.49 0.49% 0.49 0.49 0.48% _zsh_highlight__function_callable_p
13) 1 0.45 0.45 0.44% 0.45 0.45 0.44% colors
14) 3 0.38 0.13 0.37% 0.35 0.12 0.35% add-zle-hook-widget
15) 6 0.34 0.06 0.34% 0.34 0.06 0.34% is-at-least
16) 2 15.14 7.57 14.86% 0.27 0.13 0.26% _autoenv_chpwd_handler
17) 1 5.46 5.46 5.36% 0.26 0.26 0.26% _autoenv_authorized_env_file
18) 1 0.23 0.23 0.22% 0.23 0.23 0.22% regexp-replace
19) 11 0.19 0.02 0.19% 0.19 0.02 0.19% _autoenv_debug
20) 2 0.10 0.05 0.10% 0.10 0.05 0.10% wrap_clipboard_widgets
21) 16 0.09 0.01 0.09% 0.09 0.01 0.09% compdef
22) 1 0.08 0.08 0.08% 0.08 0.08 0.08% (anon) [/home/nate-wilkins/.antigen/bundles/zsh-users/zsh-autosuggestions/zsh-autosuggestions.zsh:458]
23) 2 0.05 0.02 0.05% 0.05 0.02 0.05% bashcompinit
24) 1 0.06 0.06 0.06% 0.04 0.04 0.04% _autoenv_stack_entered_remove
25) 1 5.50 5.50 5.40% 0.03 0.03 0.03% _autoenv_check_authorized_env_file
26) 1 0.04 0.04 0.04% 0.03 0.03 0.03% complete
27) 1 0.88 0.88 0.87% 0.03 0.03 0.03% async
28) 1 0.03 0.03 0.02% 0.03 0.03 0.02% (anon) [/usr/share/zsh/functions/Misc/add-zle-hook-widget:28]
29) 2 0.01 0.00 0.01% 0.01 0.00 0.01% env_default
30) 1 0.01 0.01 0.01% 0.01 0.01 0.01% _zsh_highlight__is_function_p
31) 1 0.00 0.00 0.00% 0.00 0.00 0.00% _zsh_highlight_bind_widgets
Lastly I have a perf run with a corresponding flamegraph:
perf-run --out alacritty --command "terminal -e $SHELL -slc exit"
But I'm not sure how to interpret the flamegraph since it seems to have everything in it and not just the command that was run.
So my question is: What is taking up the most time in my terminal setup and is there another approach I could use to better determine where the problem is coming from?