Re: Performance improvements

[Efraim Flashner <efraim@flashner.co.il>]

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On Mon, Oct 28, 2019 at 12:06:25AM +0100, Ludovic Courtès wrote:
> Hi!
> 
> Some more improvements come from these commits:
> 
>   ac19950507 gnu: bootstrap: Cache the 'bootstrap-executable' origins.
>   5166d02730 gnu: bootstrap: 'bootstrap-origin' preserves eq?-ness when no changes are made.
>   d727a9343d derivations: Don't memoize 'derivation->bytevector'.
>   f5fca9a82c gexp: Cache the module to derivation mappings.
>   c57e417eff store: Allow objects in the cache to be inserted and search for with 'equal?'.
>   f58b45350b gexp: Add 'imported+compiled-modules'.
>   f726f6f802 derivations: 'build-expression->derivation' caches its module derivations.
>   cf7648f882 derivations: Introduce 'imported+compiled-modules'.
> 
> This caches the module-to-derivation mapping, which wasn’t cached until
> now.
> 
> Overall the goal is to have the high-level caches work nicely (the
> “object cache” in particular), rendering the low-level caches (such as
> the ‘add-data-to-store’ cache) potentially useless.  This is beneficial
> because a cache hit on the object cache saves more CPU time than a cache
> hit on a low-level cache.
> 
> Ludovic Courtès <ludo@gnu.org> skribis:
> 
> > $ time guix build libreoffice -nd
> > /gnu/store/8drmbhsrayr2j5lkvrwq37rg8g06hgsw-libreoffice-6.1.5.2.drv
> >
> > real    0m2.142s
> > user    0m2.323s
> > sys     0m0.082s
> > $ guix describe
> > Generacio 110   Oct 14 2019 08:43:33    (nuna)
> >   guix bd04fe8
> >     repository URL: https://git.savannah.gnu.org/git/guix.git
> >     branch: master
> >     commit: bd04fe878627a14533d908ccdf5b906050d6e0a4
> 
> And now:
> 
> --8<---------------cut here---------------start------------->8---
> $ time /tmp/new/bin/guix build libreoffice -nd
> /gnu/store/ibzap0v1c367h0j2mdd2jmlsfx9jplfb-libreoffice-6.1.5.2.drv
> 
> real    0m1.658s
> user    0m1.699s
> sys     0m0.073s
> $ /tmp/new/bin/guix describe
> Generacio 1     Oct 28 2019 00:03:05    (nuna)
>   guix 271b3c9
>     repository URL: https://git.savannah.gnu.org/git/guix.git
>     branch: master
>     commit: 271b3c9d16f8880f4a27b52a615cdec611322fae
> --8<---------------cut here---------------end--------------->8---
> 

Results are even better on a slower machine:

$ time guix build libreoffice -nd
/gnu/store/ibzap0v1c367h0j2mdd2jmlsfx9jplfb-libreoffice-6.1.5.2.drv

real    0m5.408s
user    0m5.186s
sys     0m0.299s

$ time ./pre-inst-env guix build libreoffice -nd
/gnu/store/ibzap0v1c367h0j2mdd2jmlsfx9jplfb-libreoffice-6.1.5.2.drv

real    0m3.836s
user    0m3.519s
sys     0m0.235s

$ guix describe
Generation 12   Oct 27 2019 11:53:42    (current)
  ietf 8c6079e
    repository URL: https://gitlab.com/efraim/guix-ietf.git
    branch: master
    commit: 8c6079e10fdf640ce2cdafa3c1ea24961650f451
  guix 24adcba
    repository URL: https://git.savannah.gnu.org/git/guix.git
    branch: master
    commit: 24adcbab0ad903c59793dbe141950fff5058b8a2

$ ./pre-inst-env guix describe
Git checkout:
  repository: /home/efraim/workspace/guix
  branch: master
  commit: 64e3fe04b32e2eab1144d5b0c9278eab81056bd6



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Efraim Flashner   <efraim@flashner.co.il>   אפרים פלשנר
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