[PyKDE] [PATCH] reduce PyQt concatenated build time on SMP

[Gerard Vermeulen]

On Mon, Mar 24, 2003 at 03:09:17PM +0100, Hans-Peter Jansen wrote:
> On Monday 24 March 2003 13:05, Phil Thompson wrote:
> > On Monday 24 March 2003 11:53 am, Hans-Peter Jansen wrote:
> > > Hi Phil,
> > >
> > > in order to saturate multiple CPUs on SMP systems, I've created the
> > > attached patch.
> > >
> > > The problem is, that the qt module consists of 228 single modules, and
> > > build of its concatenated module outlasts all others by a few minutes
> > > here.
> > >
> > > With it applied, I was able to reduce the rpm build time from 16:15 to
> > > 13.30 on my Dual P3/1000.
> > >
> > > Since it is created on top of my former patch, it will apply with
> > > offsets, if applied first.
> >
> > But doesn't this slow it down for everybody with a UP machine?
> >
> > Phil
> 
> Well, yes, I have to admit. But the performance hit is less then the
> improvement, aka 19:53 -> 21:29 UP, AMD 2000+ (~8%), 16:15 -> 13:30 (~20%).
> 
> Would you accept a combined cleaned up patch with different lower case options
> for this and the lib stuff?
> 
If you are proposing this, why don't you generalize and code something like
the -j switch (parallel build switch) for make.

In this case there is no penalty for UP machines (by default one single
huge.cpp), and the guys with 4 processors will feel happy, too :-)

Gerard

PS: I don't have 4 processors.