Mikael Pettersson writes: > I'm seeing what appears to be a recent massive performance regression > with trunk's gengtype, as compiled and run in stage 2, on ARM V5TE. > > Right now 4.7-20110827's stage2 gengtype has been running for almost > 10 hours on my ARM build machine, but the process is tiny and no swapping > occurs. To put those 10 hours in perspective, on this machine (1.6 GHz > ARM V5TE uniprocessor running Linux) I regularly do full bootstraps and > regression test suite runs for c,c++,ada,fortran in about 18 hours for > gcc 4.4, about 20 hours for gcc 4.5, about 24 hours for gcc 4.6, and > about 27 hours for trunk until recently. So 10 hours or more just in > stage 2 gengtype is suspicious. > > I believe 4.7-20110820 also was unusually slow to build, but I didn't > monitor that build very carefully so can't say if gengtype was involved > then too.
It's now been running for almost 21 hours, with no output produced at all. According to strace it's currently not doing any syscalls, and according to gdb it's looping in yylex(). I suspect a miscompilation. Anyway I'm killing that build now. I have a pile of stable branch backports to test, after that I might try a regression hunt on trunk.