Re: iopl on ALPHA

Richard Henderson (
Tue, 16 Dec 1997 01:08:27 -0800

On Tue, Dec 16, 1997 at 06:29:12AM +0100, wrote:
> You should probably use /dev/port only
> to handle this. The performance hit of /dev/port shouldn't matter
> for this case.

What? On Alpha at least we implement everything in userspace by mmap
/dev/mem -- definitely better than syscalls using /dev/port.

And as I recall, isapnptools make many thousands of i/o port accesses;
enough so that x86 iopl vs ioperm makes a noticable speed difference.