Re: ZSH performance regression in 5.8.1.2-test

[Jordan Patterson <jordanp@gmail.com>]

On Mon, Apr 25, 2022 at 7:09 PM Bart Schaefer <schaefer@brasslantern.com> wrote:
>
> I'm curious how large is your interactive startup?  I just compared
> 5.8.1.2-test with and without the line-buffering patch running
>   zsh -xfic 'autoload compinit; compinit -D' 2>>(wc)
> and in order to get any significant difference I need to have compiled
> with --enable-zsh-debug --enable-zsh-mem-debug.
>
> wc gives 55727 lines / 1858616 characters of xtrace output, which
> ought to be enough for a reasonable comparison?

Running that gives me 56619 lines / 1866092 characters.  If I run a
benchmark with your command (without tracing), I do see some slowdown,
but not as dramatic a difference as when loading my normal zshrc with
plugins.

Benchmark 1: prefix/5.8/bin/zsh -fic "autoload compinit; compinit -D"
  Time (mean ± σ):     295.4 ms ±   4.2 ms    [User: 181.9 ms, System: 114.0 ms]
  Range (min … max):   289.0 ms … 299.8 ms    10 runs

Benchmark 2: prefix/5.8.1/bin/zsh -fic "autoload compinit; compinit -D"
  Time (mean ± σ):     295.1 ms ±   3.4 ms    [User: 183.4 ms, System: 112.1 ms]
  Range (min … max):   289.8 ms … 299.5 ms    10 runs

Benchmark 3: prefix/5.8.1.2-test/bin/zsh -fic "autoload compinit; compinit -D"
  Time (mean ± σ):     365.3 ms ±   4.2 ms    [User: 204.8 ms, System: 160.4 ms]
  Range (min … max):   358.7 ms … 373.1 ms    10 runs

Summary
  'prefix/5.8.1/bin/zsh -fic "autoload compinit; compinit -D"' ran
    1.00 ± 0.02 times faster than 'prefix/5.8/bin/zsh -fic "autoload
compinit; compinit -D"'
    1.24 ± 0.02 times faster than 'prefix/5.8.1.2-test/bin/zsh -fic
"autoload compinit; compinit -D"'