This is why I prefer using "in" and "out" to refer to I/O operations.  -Mike

On Tue, 29 May 2001, Jason R Thorpe wrote:

> Date: Tue, 29 May 2001 08:12:57 -0700
> From: Jason R Thorpe <thorpej@zembu.com>
> To: Ben Harris <bjh21@netbsd.org>
> Cc: tech-kern@netbsd.org
> Subject: Re: Oddity in physio()
>
> On Tue, May 29, 2001 at 02:03:17PM +0100, Ben Harris wrote:
>
>  >                         error = uvm_vslock(p, bp->b_data, todo,
>  >                                            (flags & B_READ) ?
>  >                                            VM_PROT_READ | VM_PROT_WRITE :
>  >                                            VM_PROT_READ);
>  >
>  > Am I missing something really obvious, or is that B_READ test backwards?
>
> A "read" from a device is a "write" to memory.  Similarly, a "write" to
> a device is a "read" from memory.
>
> --
>         -- Jason R. Thorpe <thorpej@zembu.com>
>