Re: Introduce fixed sys_sync_file_range2() syscall, implement on PowerPC and ARM

[David Woodhouse <dwmw2@infradead.org>]

On Mon, 2007-06-25 at 15:10 +0200, Segher Boessenkool wrote:
> >> I don't see any 64-bit integers here.
> >
> > Of course not. This is the routine which is called from 32-bit code.
> > The prototype in the 32-bit code is (int, unsigned, loff_t, loff_t).
> 
> Ah I see, sorry for the confusion.

> Yes exactly, signed integers need sign extensions, which
> makes them less efficient.  Some ABIs need zero extensions
> too, but on a whole unsigned works better.  Most of the
> time you don't need to do much on the (C code) kernel side
> of things.

Most of the time, true. But not in the case we're actually talking
about.

> Is this enough handwaving?  I'm sure someone else can explain
> this a lot better than me :-)

Perhaps so :)

-- 
dwmw2