[build2] LTO and parallelization with build2

[Boris Kolpackov]

Matthew Krupcale <mkrupcale at matthewkrupcale.com> writes:

> I'm not sure how widely used it is either, and Fedora will currently
> default to -flto[=full] for Clang[2]. Feel free to discard that
> portion or play around with it.

I read a bit on it and it seems thin LTO is actually considered
new/better approach compared to full. So let's keep it. I wonder
why Fedora doesn't default to that.


> Sometimes it would not schedule enough threads. But this is probably
> issue 1. you mentioned [...].

If a project has a single final link stage (e.g., an executable), then
the linker should be given all the available threads. It would be good
to confirm at least this is the case.


> A little more concerning are the following two issues.

I think these are due to a silly bug (one of those "made sure everyting
is correct expect the most trivial part") in my implementation of
allocate()/deallocate() which is now fixed in master. Can you give it a
try and see if you get a more sensible behavior?