Using O_DIRECT on Mac OS X
Is there any reason for not supporting innodb_flush_method=O_DIRECT on Mac OS X? Today I wrote a tiny patch to enable O_DIRECT on MySQL running on Mac OS X, and it seems to work fine. (mysql-5.1.30-osx-o_direct.patch)
Although I do not think it is a good idea to use Mac OS X as a database server (since it's I/O system calls are slow compared to other OSes, at least until Snow Leopard is released), having O_DIRECT support would be better than none in some cases.