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

From: Vladimir Prus (ghost_at_[hidden])
Date: 2005-03-22 03:09:43

J?rgen Hunold wrote:

> Hi !
> 
> On Tuesday 22 March 2005 08:09, Vladimir Prus wrote:
>> Daniel Goller wrote:
>> > i was wondering if there is a possibility boost (bjam?) will be
>> > supporting parallel builds better in the future, 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) and boost was
>> > no longer able to successfully build, something it did before readding
>> > support for the user selected number of jobs.
>>
>> The only problem *I* know about with  -j is that it sometimes misses
>> dependencies on generated headers (with Boost.Build V2, V1 does not
>> handle generated headers well itself). But this should not affect Boost.
> 
> Ah. This could possibly affect me ;-)
> 
> But I'm very happy with the current -j support. I normally do bjam --v2
> -j18 using SuSE's icecream and our Linux compile farm.
> See
> http://wiki.kde.org/tiki-index.php?page=icecream
> for more details on icecream ;-)
> 
>> Can you specify exactly what kind of problems you get? Note that for
>> distcc to work reliably, you need to have exactly the same version of the
>> compiler on all hosts, and preferrably a stable version. I used to get
>> segfaults otherwise.
> 
> Icecream distributes the compiler binary and libs using a tar.bz2 archive.
> This prevents these problems.
> 
> And I even do cross-compiles for AMD-64 using debian's gcc-3.4.4 ;-)
> 
> The only problem with -j18 is the link stage when linking static apps. It
> is, let's say unfortunate to have all my apps linking at the same time...

As I say in some other thread, there is a mechanism which allows to
serialize linking. Shame on me for not activating it for gcc.link.
I've just committed the relevant change -- can you verify that it works?

- Volodya