[erlang-questions] failed to enable SMP support in otp_src_R12B-1

[Mikael Pettersson]

Raymond Xiong writes:
 > On 02/20/08, Mikael Pettersson wrote:
 > > Raymond Xiong writes:
 > >  > Hello,
 > >  > 
 > >  > I have a Sun Ultra 40(a dual-core amd64 machine) which runs
 > >  > Solaris Nevada. I used to run otp_src_R12B-0 on it and had
 > >  > no problem in enabling SMP support in Erlang emulator(actually
 > >  > I did nothing for that, it was enabled automatically).
 > >  > 
 > >  > However, recently I upgrated the machine to Solaris Nevada
 > >  > latest build, which had some changes in sctp header files
 > >  > and caused otp_src_R12B-0 failed to compile. So I downloaded
 > >  > otp_src_R12B-1, configured and compiled it. But this time
 > >  > I couldn't enable SMP support, even if I configured it
 > >  > explicitly with SMP support:
 > >  > 
 > >  >    $ CPPFLAGS=-I/usr/include/gd2 ./configure --prefix=/myroot \
 > >  >      --enable-smp-support --enable-threads
 > >  > 
 > >  >    (I specified CPPFLAGS because libgd header files were placed 
 > >  >    under /usr/include/gd2 on Solaris)
 > >  > 
 > >  > Has anyone encountered the same issue?
 > > 
 > > You need to provide us with details about HOW it failed.
 > > A complete log from ./configure and make would be a good start.
 > 
 > Mikael,
 > 
 > I did some more experiments on my machine and found the following
 > results:
 > 
 > Scenario 1) 
 >   - configure with no "--enable-smp-support"
 >   - no smp support
 > 
 > Scenario 2)
 >   - confiure with "--enable-smp-support"
 >   - have smp support 
 > 
 > Scenario 3)
 >   - configure with no "--enable-smp-support"
 >   - gmake && gmake install
 >   - re-configure with "--enable-smp-support"
 >   - gmake && gmake install
 >   - still no smp support
 > 
 > Scenario 4)
 >   - configure with no "--enable-smp-support"
 >   - gmake && gmake install
 >   - gmake clean
 >   - re-configure with "--enable-smp-support"
 >   - gmake && gmake install
 >   - have smp support
 > 
 > The only difference between scenario 3 and scenario 4 is 
 > the call of "gmake clean" before re-configuration. I didn't
 > realize it's necessary before(I had thought after
 > re-configuration every thing will be rebuilt. But it seemed
 > that's not the case. Is it correct?). 

A minimum of make clean is definitely needed between config changes.
The make system to build Erlang/OTP has always been iffy.

 > I also have a question on scenario 1 and scenario 2. From
 > my testing result, "--enable-smp-support" must be specified
 > explicitly on my machine. But it was said in README that this
 > feature is detected automaticaly, is it ture?

It's autoenabled on supported machines, where supported does
not mean "it may work" but means "the OTP team regularly tests
on it and they believe it works".