> > All of my testing is being done with gcc-6.3 vanilla and current > > kernels, and in fact I'm doing parallel "make -j128" gcc and glibc > > testsuite runs and not hitting any problems at all. > > According to Eric Botcazou from gcc upstream, we most likely know the > culprit now. Eric noticed that the issue occurred within the cilk-plus > testsuite and by passing --disable-libcilkrts to configure, the testsuite > finished without problems, even with -j32. The Solaris maintainer ported Cilk++ (https://en.wikipedia.org/wiki/Cilk) to the SPARC architecture for GCC 7 and later, which explains why the issue doesn't show up with GCC 6. Cilk++ is a multithreading layer on top of C and C++ and its testsuite does a lot of thread manipulation. Note that, even when the machine doesn't freeze, the Cilk++ testsuite reports several timeouts (there are no such timeouts on Solaris): https://gcc.gnu.org/ml/gcc-testresults/2017-06/msg00462.html This is probably the most promising angle of attack: someone should look into the timeouts by running the Cilk++ testsuite with low/no parallelism and find out where they come from (compiler, Cilk++ runtime or system/kernel). I can do it, but I'm essentially a compiler guy and I don't have much expertise in multithreading at the system/kernel level. -- Eric Botcazou -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
