Re: [Boost-build] BBv2 intolerably slow in Boost tree.

From: Vladimir Prus (ghost_at_[hidden])
Date: 2006-07-27 11:08:33

On Thursday 27 July 2006 18:10, David Abrahams wrote:
> Vladimir Prus <ghost_at_[hidden]> writes:
> > On Wednesday 26 July 2006 23:20, David Abrahams wrote:
> >> >> >> > Also, can you try the attached patch to top-level Jamfile.v2?
> >> >> >>
> >> >> >> With the patch, it flies!
> >> >> >
> >> >> > What's performance of V1? I can replace the globbing code with that
> >> >> > we have there, as a quick solution.
> >> >>
> >> >> v1 is much faster than v2, even with the patch.
> >> >
> >> > Then there's something wrong in globbing code.
> >>
> >> What makes you think all the time is going into globbing?
> >
> > You reported that my patch improves performance considerably. The only
> > thing the patch does is removing globbing code.
>
> Yes, but even with the globbing removed, v2 is still considerably
> slower than v1.  That suggests to me that there is a culprit other
> than globbing.  What am I missing?

Hmm, let's go back: I said:

> >> > Then there's something wrong in globbing code.

to which you replied:

> >> What makes you think all the time is going into globbing?

I did not say that *all* of V2 runtime goes into globbing, and that by 
removing globbing we can make V2 run in 0 seconds all projects on any kind.
But if removing code that consists only of globbing makes big difference in 
performance, it means that globbing code is somehow wrong. What am I missing?

- Volodya