IBM Corp’s 64-bit AIX 4.3 operating system has a 32-bit kernel and that’s the way it’s going to stay for the foreseeable future. Big Blue says that as far as it is concerned, migrating to a 64- bit kernel is simply not as important as other 64-bit operating system work. AIX 4.3 includes all of the key 64-bit techniques for addressing more main memory, supporting larger files, 64-bit APIs for application development and 64-bit CPUs. It offers remapping tools for use with AIX 4.3 for ISVs which write 64-bit applications that make raw system-level calls to the kernel – and it thinks there will be very few of those as most address the kernel indirectly through other services, if they address it at all. There’s a negligible overhead, IBM claims. Without introducing an explicitly 64-bit kernel AIX 4.3 can run all 32- bit applications run natively without any emulation, re-writing or re-compilation, IBM says, referring to kludges incorporated by some other 64-bit Unix vendors. The jury is still out, in its mind, whether ISVs are going to write 64-bit versions of their applications in any case.
