[asdf-devel] performance of find-system (on sbcl)

[Attila Lendvai]

On Mon, Nov 16, 2009 at 16:02, Robert P. Goldman <rpgoldman at sift.info> wrote:
> I'm afraid I'm not enough of an SBCL expert to grok this unaided. Are you
> saying that by somehow telling SBCL it's in interpret mode, that speeds up
> find-system? And is this surprising? I would have guessed that parsing and
> possibly compiling the .asd file would take most of the time...


well, the process is surprisingly slow compared to what's really
happening. it's not an asdf issue, but sbcl's slow load-file. turning
on the interpreted eval mode speeds it up considerably, because sbcl's
compiler is focusing on code quality instead of compilation speed.

it shouldn't be a problem as the result of the compilation is thrown
away anyway after a single evaluation (except maybe closures that end
up being permanently stored somewhere as the sideffect of loading the
.asd file)


> Is this a proposed sbcl-specific optimization ?


i'm not sure that i'm aware of all the possible consequences of this
(thinking of more complex .asd files defining functions, etc), but
adding this to asdf visually speeds up the slow .asd parsing phase for
me i see here and there. (our end projects have around 90
dependencies, some of them with multiple .asd files).

-- 
 attila