Hi Sam, On Sun, May 31, 2015 at 08:05:44PM -0400, Sam Varshavchik wrote: > Suvayu Ali writes: > > > >How does rpmbulid decide how many threads to run? I think it looks at > >the local machine and decides. I also recall some variable called > >RPMBUILD_NCPU or something like that. That would explain why it only > >uses as many threads as the local machine can handle. > > > >Hope this helps, > > Sadly, no it doesn't. As I wrote above: > > >> >> >> ps shows the maximum number of "/usr/bin/distcc /usr/bin/g++ > >[options]" > >> >> >> processes running locally, > > rpmbuild uses the _smp_mflags macro to pass the -j parameter to make, and I > have it correctly configured to kick off ten parallel processes, to match > the maximum number of ten processes distcc is configured (4 local, 6 > remote). Yet, despite the fact that a manual build distributes the compiles > correctly, with rpmbuild distcc throttles the number of concurrent parallel > jobs that it kicks off to four, and runs them locally. I think you misunderstood me, I wasn't clear either. I saw you set _smp_mflags, what I mean is rpmbuild still does some magic underneath. I.e. after you have set that flag, afaik, rpmbuild will fiddle with the value and pass an "appropriate" -j<n> flag to Make in the regular case. It makes this choice based on how many threads it can run locally. At least that's what I think it does. Okay I did some digging. This is what rpmbuild does with _smp_mflags (output from rpmbuild --showrc). -14: _smp_mflags %([ -z "$RPM_BUILD_NCPUS" ] \ && RPM_BUILD_NCPUS="`/usr/bin/getconf _NPROCESSORS_ONLN`"; \ ncpus_max=%{?_smp_ncpus_max}; \ if [ -n "$ncpus_max" ] && [ "$ncpus_max" -gt 0 ] && [ "$RPM_BUILD_NCPUS" -gt "$ncpus_max" ]; then RPM_BUILD_NCPUS="$ncpus_max"; fi; \ if [ "$RPM_BUILD_NCPUS" -gt 1 ]; then echo "-j$RPM_BUILD_NCPUS"; fi) -14: _smp_ncpus_max 16 I don't have the time to check the above snippet, maybe you can take a look? Hope this time we follow each other. If this doesn't help, I'm out of ideas :-(.

Once again: the correct number of distcc processes get started. But they throttle each other, and only four, at a time, kick off a compile on localhost, the configured distcc max job setting for localhosts, with the others waiting until the earlier ones finish, before starting the real g++.

On Sun, May 31, 2015 at 03:29:29PM -0400, Sam Varshavchik wrote: > Suvayu Ali writes: > > >On Sun, May 31, 2015 at 01:24:07PM -0400, Sam Varshavchik wrote: > >> > >> >> ps shows the maximum number of "/usr/bin/distcc /usr/bin/g++ [options]" > >> >> processes running locally, that I but nothing gets distributed to other > >> >> hosts. > >> > >> I've got distcc configured for 10 concurrent builds. 4 local, 6 distributed > >> to another host. I see ten distcc processes on the local machine during the > >> rpmbuild, /var/log/messages on the other host shows nothing – it logs > >distcc > >> server activity otherwise – and the local host appears to be running only > >> four concurrent compiles. > > > >Are you running under mock? Maybe chroot is preventing remote builds? > > No, this is an ordinary rpmbuild. How does rpmbulid decide how many threads to run? I think it looks at the local machine and decides. I also recall some variable called RPMBUILD_NCPU or something like that. That would explain why it only uses as many threads as the local machine can handle. Hope this helps,

> >> >> ps shows the maximum number of "/usr/bin/distcc /usr/bin/g++ [options]" > >> >> processes running locally,

On Sun, May 31, 2015 at 01:24:07PM -0400, Sam Varshavchik wrote: > > >> ps shows the maximum number of "/usr/bin/distcc /usr/bin/g++ [options]" > >> processes running locally, that I but nothing gets distributed to other > >> hosts. > > I've got distcc configured for 10 concurrent builds. 4 local, 6 distributed > to another host. I see ten distcc processes on the local machine during the > rpmbuild, /var/log/messages on the other host shows nothing – it logs distcc > server activity otherwise – and the local host appears to be running only > four concurrent compiles. Are you running under mock? Maybe chroot is preventing remote builds?

As I recall, distcc involves running distcc instead of gcc. Do the RPM builds somehow override which compiler get used to use the standard gcc compiler instead of distcc? Perhaps through an environment variable in the build script?

> ps shows the maximum number of "/usr/bin/distcc /usr/bin/g++ [options]" > processes running locally, that I but nothing gets distributed to other > hosts.