For 64-bit, the hack consists of a switch that chooses whether to use a fixed address or a generically-assigned one, that's all there is to it. So it costs about nothing.
Even for 32-bit, CONFIG_COMPAT_VDSO for a while now is doing nothing but changing the default of the sysctl variable. There the fixmap part is some extra stuff that could go away in the ideal in the fullness of time. But it doesn't hurt to keep it, especially when never turned on. The upshot of my changes is that whatever the choices available for the layout of 32-bit address spaces, they should match on 32-bit and 64-bit kernels. If you want to reduce that set of choices in both, that is a separate issue. Thanks, Roland - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/