Re: Guile's time execution issues

[Ludovic Courtès]

Hola!

Aleix Conchillo Flaqué <address@hidden> skribis:

> On guile-json 3.5.0 (still using (string-append)) the first execution time
> goes from 19 seconds to 42 seconds. Then, the times keep increasing as in
> version 2.2.7 but numbers are much bigger:

With Guile 3.0.2 and Guile-JSON 3.5.0, I get:

--8<---------------cut here---------------start------------->8---
$ guile
GNU Guile 3.0.2
Copyright (C) 1995-2020 Free Software Foundation, Inc.

Guile comes with ABSOLUTELY NO WARRANTY; for details type `,show w'.
This program is free software, and you are welcome to redistribute it
under certain conditions; type `,show c' for details.

Enter `,help' for help.
scheme@(guile-user)> ,use(json)
scheme@(guile-user)> ,t (->bool (call-with-input-file "/tmp/large-file.json" 
json->scm))
$1 = #t
;; 55.142128s real time, 79.806656s run time.  65.418070s spent in GC.
scheme@(guile-user)> ,t (->bool (call-with-input-file "/tmp/large-file.json" 
json->scm))
$2 = #t
;; 47.416645s real time, 75.274219s run time.  62.421108s spent in GC.
scheme@(guile-user)> ,t (->bool (call-with-input-file "/tmp/large-file.json" 
json->scm))
$3 = #t
;; 41.292368s real time, 79.053120s run time.  67.266710s spent in GC.
--8<---------------cut here---------------end--------------->8---

So I think the time increase was just due to the fact that previous
parse results were kept around, somehow.

2.2.7 performs comparably for me:

--8<---------------cut here---------------start------------->8---
$ guix environment -C --ad-hoc guile-json guile@2.2 --share=/tmp -- guile 
guix environment: warning: plursenca pak-specifigo 'guile@2.2'
guix environment: warning: choosing guile@2.2.7 from 
gnu/packages/guile.scm:256:2
GNU Guile 2.2.7
Copyright (C) 1995-2019 Free Software Foundation, Inc.

Guile comes with ABSOLUTELY NO WARRANTY; for details type `,show w'.
This program is free software, and you are welcome to redistribute it
under certain conditions; type `,show c' for details.

Enter `,help' for help.
scheme@(guile-user)> ,use(json)
scheme@(guile-user)> ,t (->bool (call-with-input-file "/tmp/large-file.json" 
json->scm))
$1 = #t
;; 44.963180s real time, 90.606198s run time.  71.529811s spent in GC.
scheme@(guile-user)> ,t (->bool (call-with-input-file "/tmp/large-file.json" 
json->scm))
$2 = #t
;; 44.147740s real time, 87.796937s run time.  69.818018s spent in GC.
scheme@(guile-user)> ,t (->bool (call-with-input-file "/tmp/large-file.json" 
json->scm))
$3 = #t
;; 45.057761s real time, 89.689930s run time.  71.370764s spent in GC.
--8<---------------cut here---------------end--------------->8---

So to me, Guile is behaving correctly here.

Now, it would be good to profile ‘json->scm’ to see if there’s anything
that could be improved on the Guile side, or if it’s just a normal
profile for GC-intensive code.

Thanks,
Ludo’.