The end of the multiarch era?

Posted Jul 13, 2006 10:32 UTC (Thu) by nix (subscriber, #2304)
Parent article: The end of the multiarch era?

Multiarch may be unnecessary (in the long run) on x86-64, but it will always be needed on other platforms, on which the common case is to keep things 32-bit because the only difference between 64-bitness and 32-bitness on those platforms is alignment constraints, accessible address space, and the sizes of pointer and integral types. Going 64-bit thus has disadvantages (reduced speed and more cache misses, increased memory usage and disk space consumption) that more than counter the advantages.

Ones which spring immediately to mind include MIPS64 and SPARC64. On such platforms, the only stuff which tends to be 64-bit is kernel code and things which truly benefit (mathematical stuff, stuff which needs huge address spaces like perhaps image processing software, and things which really benefit from the extra size of words, like Emacs). Everything else is left 32-bit. (As others have commented, though, the only things which ever need two copies of themselves installed are *libraries* and in rare circumstances a few header files; the rest should have only one arch's version installed.)

So multiarch continues to be useful.