[Asdf-devel] startup times and initialize-source-registry

[Faré]

>> Any insta-theories for where other half second comes from?
>>
> If you mean the second half of cl-launch's startup time, I fear it
> might be a combination of shell and CL compilation overhead, but I
> admit I haven't tried timing where the time is going. You're welcome
> to investigate. At some point, I was thinking of translating cl-launch
> to CL and having it output a bootstrap script to make itself. Then it
> would have a "fast" mode that loads code onto the cl-launch image,
> rather than start a new process (with maybe a different CL
> implementation) to implement the requested software. At that point,
> maybe Xach's buildapp is a better starting point. Or not.
>
The other half of cl-launch's startup time is spent in CL, and is
definitely a performance bug:
% time env SBCL=/bin/true cl -ip 1
env SBCL=/bin/true cl -ip 1  0.03s user 0.02s system 102% cpu 0.045 total
% time env CL_SOURCE_REGISTRY="/does/not/exist" cl -ip 1
env CL_SOURCE_REGISTRY="/does/not/exist" cl -ip 1  0.43s user 0.06s
system 98% cpu 0.494 total

Inserting a few (time) forms and enabling verbose loading, I find that
the cl:load'ing of cl-launch itself is taking most of the time, and
the most time in that is loading then upgrading asdf, i.e. loading the
fasl's for it. I'm not sure how to speed THAT up; ASDF is big, and not
likely to shrink significantly while preserving backward
compatibility. SBCL also seems to be spending some notable fraction of
the time compiling the cl-launch code itself, though most of the time
is the fasl loading. Conclusion: FASt Loading is only so "fast".

PS: your topology.sh file has a ":" ; # ... comment as if it were a
bilingual script, but it isn't bilingual.
Also, the path /usr/local/bin/cl is not standard and neither is the -S argument.

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