Re: powerpc allyesconfig / allmodconfig linux-next next-20160729 - next-20160729 build failures

From: Arnd Bergmann
Date: Wed Aug 03 2016 - 16:14:56 EST


On Wednesday, August 3, 2016 2:44:29 PM CEST Segher Boessenkool wrote:
> Hi Arnd,
>
> On Wed, Aug 03, 2016 at 08:52:48PM +0200, Arnd Bergmann wrote:
> > From my first look, it seems that all of lib/*.o is now getting linked
> > into vmlinux, while we traditionally leave out everything from lib/
> > that is not referenced.
> >
> > I also see a noticeable overhead in link time, the numbers are for
> > a cache-hot rebuild after a successful allyesconfig build, using a
> > 24-way Opteron@xxxxxx, just relinking vmlinux:
> >
> > $ time make skj30 vmlinux # before
> > real 2m8.092s
> > user 3m41.008s
> > sys 0m48.172s
> >
> > $ time make skj30 vmlinux # after
> > real 4m10.189s
> > user 5m43.804s
> > sys 0m52.988s
>
> Is it better when using rcT instead of rcsT?

It seems to be noticeably better for the clean rebuild case, though
not as good as the original:

real 3m34.015s
user 5m7.104s
sys 0m49.172s

I've also tried now with my own patch applied as well (linking
each drivers/*/built-in.o into vmlinux rather than having them
linked into drivers/built-in.o first), but that makes no
difference.

Arnd