4 ms·
It is a technical limitation. Oftentimes the platform is so specialized that only a tiny handful of compilers are ported to it. Say, just gcc, g++, and gfortran
by wnissen 11y ago
It is a technical limitation. Oftentimes the platform is so specialized that only a tiny handful of compilers are ported to it. Say, just gcc, g++, and gfortran, and xlc, xlC, and xlf. And just one version at that. Java would require porting the JVM to the cut-down, weird Linux on the compute nodes. Some $$$ machines don't even support dynamic linking! The number of these machines is so small that extensive compiler and tool support just isn't happening unless you want to add millions to the cost.
- dekhn 11y agoThere is no problem running a JVM on cut-down linux nodes. A JVM is just a process. Anyway, the issue with JVMs is that they don't have predictable performance, not that the compilers can't be ported.
- wnissen 11y agoThe JVM probably calls fork() and system(), no? Not allowed. Dynamic thread creation? Not allowed. And 50% of your flops go away unless your program uses the BG/Q-specific "double hummer" floating point instructions. These are primitive machines, in terms of development environment and typically require significant rewriting to get even "standard" system software working.