[Boost-users] Re: boost parallel build, will it get better?

From: David Abrahams (dave_at_[hidden])
Date: 2005-03-19 23:20:15

Daniel Goller <morfic_at_[hidden]> writes:

> Hi,
>
> i was wondering if there is a possibility boost (bjam?) will be
> supporting parallel builds better in the future

This really belongs on the Jamboost list:
http://www.boost.org/more/mailing_lists.htm#jamboost.  I'm not sure
any of us knew there was a problem with parallel builds.

> i was testing building with -j5 (-j5 is about the sweet spot at
> which distcc creates enough load on the helping XP3200 for this mac
> mini i work on) 

distcc?  XP3200?  mac mini?

I probably don't really need to know what these mean, but I'm curious.

> and boost was no longer able to successfully build,

What was the result?  What errors did you see?  Do you have any reason
to believe the problem was connected to the -j option?

> something it did before readding support for the user selected
> number of jobs.  

Somebody re-added support for the -j option?  When did support for -j
ever go away?  Or am I misunderstanding you?

> Basically im wondering what to tell users who start
> to notice we do not support their -jN settings ("bear with us it'll
> work in future" vs "we do not know if it will ever work") 

How about "we do not know that it's even broken?" ;-)

> after having received notice that supporting make options might not
> be taken well by bjam (and being able to confirm this with distcc),
> while at the same time wishing i could take advantage of distcc
> myself.
>
> Is this something of concern to boost, or will it most likely remain
> at the state as it is in the 1.32.0 release?

We're definitely concerned with making sure that parallel builds work,
especially if there's currently a problem.  That said, as soon as BBv2
replaces BBv1 (soon!) we are probably going to start concentrating on
transitioning from the use of bjam's build engine to that of Scons,
which does support parallel builds very nicely.  At that point,
responsibility for support of parallelism will be on the shoulders of
the Scons guys ;-)

HTH,

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com