Re: compat-wireless: ridiculous build speed

[Michael Buesch <mb@bu3sch.de>]

On Thursday 11 June 2009 23:10:52 Luis R. Rodriguez wrote:
> On Thu, Jun 11, 2009 at 2:05 PM, Michael Buesch<mb@bu3sch.de> wrote:
> > On Thursday 11 June 2009 20:48:13 Luis R. Rodriguez wrote:
> >> On Thu, Jun 11, 2009 at 2:29 AM, Jan Kiszka<jan.kiszka@web.de> wrote:
> >> > Hi,
> >> >
> >> > while watching compat-wireless-2009-06-11 doing baby-steps building all
> >> > its modules, I wonder what slows this down so horribly. No other
> >> > external module build package I know is that slow (I would say *at
> >> > least* one order of magnitude slower than normal). Is this really required?
> >> >
> >> > [ Hurray, it's finished! ]
> >>
> >> I think the many depmod -ae are the culprit. This is in place to
> >> account for all the crap of madwifi which may be present or older
> >> drivers which have been renamed.
> >>
> >> This could be improved. Patches are welcomed.
> >>
> >> Ps. Try building with make -j 2, etc.
> >
> > -j does not help. It will hardly build in parallel then.
> 
> It works swell for me. The only thing that does not build in parellel
> is the autoconf stuff but after its done with that step everything
> builds as expected with -j 2.
> 
> > There's something
> > that serializes most of it (implicitly).
> 
> You certain its just not the first part? I had written some patches to
> make the first autoconf step into another step to then allow make -j
> foo to work without a warning but that would involve another step. The
> -j option does work for me though.

Well, I never measured it, but I don't see any advantage when using -jX. Maybe
that is because forever equals forever+1.

What I do see, though, is that the per-cpu load is much higher when building the
kernel itself with the same -j parameter.

-- 
Greetings, Michael.