From: Ricardo Wurmus <rekado@elephly.net>
To: Liliana Marie Prikler <liliana.prikler@ist.tugraz.at>
Cc: gwl-devel@gnu.org
Subject: Re: Processing large amounts of files
Date: Thu, 21 Mar 2024 16:03:37 +0100 [thread overview]
Message-ID: <877chvehuu.fsf@elephly.net> (raw)
In-Reply-To: <2010bdb88116d64da3650b06e58979518b2c7277.camel@ist.tugraz.at>
Liliana Marie Prikler <liliana.prikler@ist.tugraz.at> writes:
> For comparison:
> time cat /tmp/meow/{0..7769}
> […]
>
> real 0m0,144s
> user 0m0,049s
> sys 0m0,094s
>
> It takes GWL 6 times longer to compute the workflow than to create the
> inputs in Guile, and 600 times longer than to actually execute the
> shell command. I think there is room for improvement :)
GWL checks if all input files exist before running the command. Part of
the difference you see here (takes about 2 seconds on my laptop) is GWL
running FILE-EXISTS? on 7769 files. This happens in prepare-inputs; its
purpose:
"Ensure that all files in the INPUTS-MAP alist exist and are linked to
the expected locations. Pick unspecified inputs from the environment.
Return either the INPUTS-MAP alist with any additionally used input
file names added, or raise a condition containing the list of missing
files."
Another significant delay is introduced by the cache mechanism, which
computes a unique prefix based on the contents of all input files. It's
not unexpected that this will take a little while, but it's not great
either.
The rest of the time is lost in inferior package lookups and in using
Guix to build a script that likely already exists. The latter is
something that we could cache (given identical output of "guix describe"
we could skip the computation of the process scripts).
--
Ricardo
next prev parent reply other threads:[~2024-03-21 15:16 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <2010bdb88116d64da3650b06e58979518b2c7277.camel@ist.tugraz.at>
2024-03-21 14:34 ` Processing large amounts of files Ricardo Wurmus
2024-03-25 7:42 ` Liliana Marie Prikler
2024-03-25 9:25 ` Ricardo Wurmus
2024-03-25 10:42 ` Ricardo Wurmus
2024-03-21 15:03 ` Ricardo Wurmus [this message]
2024-03-21 15:33 ` Liliana Marie Prikler
2024-03-26 21:30 ` Ricardo Wurmus
2024-03-27 7:10 ` Liliana Marie Prikler
2024-03-27 9:58 ` Ricardo Wurmus
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