zplugin ice atinit'zmodload zsh/zprof' \
    atload'zprof | head -n 20; zmodload -u zsh/zprof'
zplugin light zdharma/fast-syntax-highlighting
  • atinit'' loads zsh/zprof module (shipped with Zsh) before loading the plugin – this starts the profiling,
  • atload'' works after loading the plugin – shows profiling results (zprof | head), unloads zsh/zprof - this stops the profiling; in the effect, only a single plugin (in this case zdharma/fast-syntax-highlighting) will be profiled while the rest of the e.g. zshrc processing will go on completely normally,
  • the light loads without reporting enabled, so less Zplugin code is being run – no Zplugin code responsible for the tracking (i.e. the automatic data gathering, during loading of a plugin, for the reports and the possibility to unload the plugin) will be activated and the functions will not appear in the zprof report.
  • example zprof report: 
num calls    time                self                 name
---------------------------------------------------------------------------
 1)  1 57,76 57,76 57,91%  57,76 57,76 57,91% _zsh_highlight_bind_widgets
 2)  1 25,81 25,81 25,88%  25,81 25,81 25,88% compinit
 3)  4 10,71  2,68 10,74%   8,71  2,18  8,73% --zplg-shadow-autoload
 4) 43  2,06  0,05  2,07%   2,06  0,05  2,07% -zplg-add-report
 5)  8  1,98  0,25  1,98%   1,98  0,25  1,98% compdef
 6)  1  2,85  2,85  2,85%   0,87  0,87  0,87% -zplg-compdef-replay
 7)  1  0,68  0,68  0,68%   0,68  0,68  0,68% -zplg-shadow-off
 8)  1  0,79  0,79  0,79%   0,49  0,49  0,49% add-zsh-hook
 9)  1  0,47  0,47  0,47%   0,47  0,47  0,47% -zplg-shadow-on
10)  3  0,34  0,11  0,35%   0,34  0,11  0,35% (anon)
11)  4 10,91  2,73 10,94%   0,20  0,05  0,20% autoload
12)  1  0,19  0,19  0,19%   0,19  0,19  0,19% -fast-highlight-fill-option-variables
13)  1 25,98 25,98 26,05%   0,17  0,17  0,17% zpcompinit
14)  1  2,88  2,88  2,89%   0,03  0,03  0,03% zpcdreplay
15)  1  0,00  0,00  0,00%   0,00  0,00  0,00% -zplg-load-plugin
-----------------------------------------------------------------------------------
  • the first column is the time is in milliseconds; it denotes the amount of time spent in a function in total
    • so for example, --zplg-shadow-autoload consumed 10.71 ms of the execution time,
  • the fourth column is also a time in milliseconds, but it denotes the amount of time spent on executing only of function's own code, i.e. it doesn't count the time spent in descendant functions that are called from the function;
    • so for example, --zplg-shadow-autoload spent 8.71 ms on executing only its own code.
  • the table is sorted on the self-time column.