Subject: Re: letting userland issue FUA writes
To: Jason Thorpe <>
From: Bill Studenmund <>
List: tech-kern
Date: 03/17/2006 17:16:33
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Fri, Mar 17, 2006 at 02:52:57PM -0800, Jason Thorpe wrote:
> On Mar 17, 2006, at 2:43 PM, Bill Studenmund wrote:
> >If you want to experiment with such a thing, go for it. If we are =20
> >cooking
> >up a new interface, though, I am only interested in basically a =20
> >pwrite()
> >and a pwritev() calls (with different names!!) that also takes a flags
> >value, and the flags value can include a flag to trigger FUA.
> My suggestion would be preadx() / pwritex().  FUA is applicable for =20
> reads, too.  They would be exactly like preadv() / pwritev(), but =20
> also have the flags parameter.

Ok, I like the 'x' syntax.

Yes, I know it applies to reads too. I'd need help doing the UVM magic to=
make that happen (basically flush the cache, zap the pages, then re-read=20

Just to be clear, we're talking about not having an equivalent to
pread/pwrite? I can live with that.

Take care,


Content-Type: application/pgp-signature
Content-Disposition: inline

Version: GnuPG v1.2.3 (NetBSD)