Re: Optimizing ‘guix package’

[Mark H Weaver <mhw@netris.org>]

ludo@gnu.org (Ludovic Courtès) writes:

> Mark H Weaver <mhw@netris.org> skribis:
>
>> * Although I can now run union-build in 2 minutes, another full minute
>>   is spent in 'display-search-paths',
>
> Commit 27c6845 optimizes that (50%!).

Oooh, this makes a significant improvement on my YeeLoong :)

> The problem is that currently this is an inherently inefficient
> operation: search path information is not stored in the manifest, so
> ‘search-path-environment-variables’ has to look up the package
> corresponding to each manifest entry to find out what the search path
> variables are.  That involves traversing the module tree, which does a
> lot of I/O (this is OKish on an SSD, but much less on a real hard disk.)
>
> Perhaps eventually we could store search path info in manifest entries.

Sounds good to me.  When we make union smarter about handling conflicts,
it may be that some hints from the individual packages should be
consulted, and perhaps those hints should go in the manifest as well.

    Thanks!
      Mark