Re: [lmi] Built today's wx-2.9.2 snapshot

[Greg Chicares]

On 2011-07-07 21:52Z, Greg Chicares wrote:
> On 2011-07-07 10:09Z, Greg Chicares wrote:
>> 
>> With the wx-2.9.2 release, [...]
> 
> I happened to build it without parallelism the first time, so it didn't
> take much more time to experiment with faster builds. Output of
>   /lmi/src/lmi[0]$time make --jobs=X -f install_wx.make >../log 2>&1
> for various 'X', where RAM grows scarce for values above eight or so:
> 
> make --jobs=12 -f install_wx.make > ../log 2>&1  641.02s user 652.96s system 
> 158% cpu 13:34.94 total
> make --jobs=10 -f install_wx.make > ../log 2>&1  642.12s user 552.46s system 
> 185% cpu 10:43.17 total
> make --jobs=8  -f install_wx.make > ../log 2>&1  636.90s user 489.91s system 
> 171% cpu 10:56.47 total
> make --jobs=6  -f install_wx.make > ../log 2>&1  637.67s user 442.59s system 
> 148% cpu 12:06.82 total
> make --jobs=4  -f install_wx.make > ../log 2>&1  637.38s user 401.23s system 
> 118% cpu 14:34.94 total
> make --jobs=2  -f install_wx.make > ../log 2>&1  631.58s user 366.12s system  
> 72% cpu 22:59.91 total
> make           -f install_wx.make > ../log 2>&1  634.96s user 355.27s system  
> 40% cpu 40:41.27 total

Building 'wxWidgets-2013-07-11.tar.gz' with the same compiler,
but with '--param ggc-min-expand=25 --param ggc-min-heapsize=32768':

make --jobs=16 -f install_wx.make > ../log 2>&1  622.18s user 293.25s system 
162% cpu 9:23.34 total
make --jobs=8 -f install_wx.make > ../log 2>&1  616.95s user 256.79s system 
122% cpu 11:50.95 total

With gcc tuned that way, I always have more than one gigabyte free,
and 800M in use by other processes, so building uses only about
two gigabytes. These results are consistent with the notes in
'workhorse.make':

# As this is written in 2012, lmi is often built on machines with less
# RAM per core than gcc wants. Experiments show that these flags cut
# gcc's RAM appetite by fifty percent, in return for a ten-percent
# speed penalty that can be overcome by increasing parallelism.