On Tue, 10 Jun 2008 16:11:49 +0200
Rémi Cardona <remi@g.o> wrote:
> Ciaran McCreesh a écrit :
> > The package manager does not currently source the whole thing with
> > bash to get the EAPI, nor does it open the ebuild file at all for
> > metadata. You're talking doubling the number of file operations
> > here, and going from extremely good filesystem locality (which
> > means very few seeks) to jumping backwards and forwards all over
> > the place.
> 
> Yeah, grepping through the ebuild is just bound to get a massive 
> performance hit, I don't have numbers but that just looks obvious.

No no. Doing the seek to open a file in a different directory and then
seeking back to your original directory over and over when otherwise
you'd be doing nice linear opens on adjacent inodes in a single
directory is where the performance hit is.

Paludis is pretty much seek bound in a lot of cases.

> Ciaran, what other pitfalls do you see for using one EAPI file per 
> package (except for the broken compatibility, I know it's a big one) ?

It's moving the relevant information further and further away from
where it's supposed to be. It doubles the number of files a developer
has to check in order to do simple ebuild maintenance.

-- 
Ciaran McCreesh