bug#19390: 25.0.50; `package-activate' is too slow

[Dmitry Gutov <dgutov@yandex.ru>]

On 12/18/2014 05:15 PM, Artur Malabarba wrote:

> There's a bit of a small flaw with that approach, it's the reason I used
> find-library.
> If you just check load files against their names, you could find a wrong
> file that has the same name as a feature (we require files in the load
> path to be uniquely named, but load-history contains all files, not just
> those in the load path).

Like mentioned, we can also check against the `provide' values in each 
load-history element we find matching. Shouldn't be a perceptible 
performance hit.

> It's an edge case, and my opinion is that a good performance improvement
> is more important than that. But it seems like the 2 biggest performance
> improvements have already been made (the package initialize, and the
> file true name), so I wonder if it's worth it.

200ms per package initialization still seems a lot to me (even if it's 
only for certain packages). I also happen to think that the suggested 
code is a bit easier to understand, but it's up to you.