I'm a new contributor and would like advice

I'm a new contributor and would like advice

[Hazel Cooney]

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Hi Guix team!

My name is Evan Cooney, I'm 17 years old and I'm interested in contributing
to guix. Specifically, I want to try to improve the performance of
installing packages. I'm not a very experienced user of Guix System, but I
used it for at least a few months on my desktop and I noticed that guix
install was weirdly slow at installing packages, even small ones. What
appeared to be the actual downloading of the binaries and other things went
fairly quickly, but at the last stage of the installation, it seemed to
hang for at least a few minutes before finishing. It said it was "building
profile with (some number) packages", and it took at least 2 minutes on
that stage only no matter the size of the package. I think this is weird
because I have a relatively powerful computer (Ryzen 5 5600 [6 cores, 12
threads], 16GB DDR4, 1TB SSD). Guix also used 100% of the CPU while it was
building the profile. Correct me if I'm wrong, but isn't the profile just a
bunch of files? It seems like it should not take 2 minutes using 100% of 12
threads just to create some files. Could you give me any advice on how to
start working on this issue and anyone to contact for further
information/help?

Thank you,
Evan Cooney

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Re: I'm a new contributor and would like advice

[Felix Lechner via Development of GNU Guix and the GNU System distribution.]

Hi Evan,

On Wed, Jul 31 2024, Hazel Cooney wrote:

> It should not take 2 minutes using 100% of 12 threads just to create
> some files.

I'm also a newbie and wish I had equipment like yours!

Profiles might be composed of symbolic links, which can take time to
resolve on rotating disks, if you have those.

The 100% CPU use could be related to the computation of "derivations."
They help Guix decide which software you need on your system.

Kind regards
Felix

Re: I'm a new contributor and would like advice

[Ludovic Courtès]

Hi Hazel,

Hazel Cooney <evancooney71@gmail.com> skribis:

> before finishing. It said it was "building profile with (some number) packages", and it took at least 2 minutes on that stage only no
> matter the size of the package.

This is surprisingly long, indeed.

Do you use an SSD or a rotating disk?  As Felix mentioned, the latter is
likely to be quite slow for these operations.

Also, the duration of this operation depends on the number of packages
in the profile, and more or less on the number of files involved.  It
would help if you could reproduce the slowness with as few packages as
possible to see if we can identify some pathological behavior.

Thanks,
Ludo’.

Re: I'm a new contributor and would like advice

[Hazel Cooney]

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Ok, I'll try to reproduce with as few packages as I can. I'm working on a
script to test performance of only the "building profile" stage with
various numbers of packages.
I use an relatively new NVME SSD from Samsung. I got it a couple years ago.
I'll have to check back on its read/write performance, I don't remember the
model number. I'm sorry for taking a while to respond, I've been on
vacation for the last week and haven't been checking  my email.

Also, I know my email says it was sent from "Hazel Cooney" but I don't go
by that name anymore. I would prefer it if you called me Evan.

Thank you,
Evan Cooney

On Mon, Aug 12, 2024, 8:31 AM Ludovic Courtès <ludo@gnu.org> wrote:

> Hi Hazel,
>
> Hazel Cooney <evancooney71@gmail.com> skribis:
>
> > before finishing. It said it was "building profile with (some number)
> packages", and it took at least 2 minutes on that stage only no
> > matter the size of the package.
>
> This is surprisingly long, indeed.
>
> Do you use an SSD or a rotating disk?  As Felix mentioned, the latter is
> likely to be quite slow for these operations.
>
> Also, the duration of this operation depends on the number of packages
> in the profile, and more or less on the number of files involved.  It
> would help if you could reproduce the slowness with as few packages as
> possible to see if we can identify some pathological behavior.
>
> Thanks,
> Ludo’.
>

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