Re: [PATCH v2] Add preadv and pwritev system calls.

[David Miller <davem@davemloft.net>]

From: Paul Mackerras <paulus@samba.org>
Date: Mon, 15 Dec 2008 15:14:18 +1100

> Matthew Wilcox writes:
> 
> > On Fri, Dec 12, 2008 at 03:00:40PM +0100, Gerd Hoffmann wrote:
> > > The patch sports the actual system call implementation and the windup in
> > > the x86 system call tables.  Other archs are TBD.
> > 
> > > +asmlinkage ssize_t sys_preadv(unsigned long fd, const struct iovec __user *vec,
> > > +                              unsigned long vlen, loff_t pos)
> > > +asmlinkage ssize_t sys_pwritev(unsigned long fd, const struct iovec __user *vec,
> > > +                               unsigned long vlen, loff_t pos)
> > 
> > Are these prototypes required?  MIPS and PARISC will need wrappers to
> > fix them if they are.  These two architectures have an ABI which
> > requires 64-bit arguments to be passed in aligned pairs of registers,
> 
> As does 32-bit PowerPC, so I also would prefer the alternate argument
> order for the syscall (pos as the 3rd argument).

FWIW 32-bit sparc does not have the aligned register requirement
for 64-bit arguments.