[distcc] Cygwin hosted distcc toolchain (updated)

[Harold L Hunt II]

Perochon Sebastien wrote:

> 	Hi all,
> 
> I have try distcc on Cygwin on 3 computers with exctly the same
> configuration:
> Pentium 3, 1 Ghz, 10Mb ethernet
> 
> I have test a lot of configuration:
> 
> localhost computer2 computer3
> computer2 computer3 localhost
> ...
> 
> with -j = 2 * CPUs
> 
> And it appears that the best configuration is to not set localhost in the
> configuration file. But the gain is maximum about 20%... only...
> 
> The problem is that the preprocessing of each of my file take a lot of time
> (more than the compilation itself). The CPU of my computer is at 100% just
> by preprocessing 4 files for the 2 others computers !!!
> 
> Is it normal ???
> 
> Is there a magic way to reduce the preprocessing time ?

You found the magic tip: don't include localhost in the DISTCC_HOSTS 
file.  Also, make sure that your very fastest machine is the build host, 
since, as you noted, preprocessing takes forever on Cygwin.  The reason 
for this is that the emulation of fork() is difficult to do with the 
facilities that Win32 provides, thus it takes a lot of time.  I have 
seen pretty much the same performance that you described.

Harold