For 1: I don't remember exactly which machines use NUMA, but I thought it was limited to 1st Opterons (and the behaviour makes sense)
2: Not sure, this may be specific to FS, or something that has to do with the behaviour of MMAPed files however I don't know how do you guarantee that what you're writing corresponds to a single block in the FS (unless you're writing directly to /dev/sda and even then)
2: Not sure, this may be specific to FS, or something that has to do with the behaviour of MMAPed files however I don't know how do you guarantee that what you're writing corresponds to a single block in the FS (unless you're writing directly to /dev/sda and even then)