Re: [RFC] [PATCH] cache pollution aware __copy_from_user_ll()

Andi Kleen
2005-08-15T15:13:36Z

On Mon, Aug 15, 2005 at 05:09:12PM +0200, Arjan van de Ven wrote:
> On Mon, 2005-08-15 at 17:02 +0200, Andi Kleen wrote:
> > Arjan van de Ven <arjan@infradead.org> writes:
> >
> > > On Mon, 2005-08-15 at 08:15 -0400, linux@horizon.com wrote:
> > > > Actually, is there any place *other* than write() to the page cache that
> > > > warrants a non-temporal store? Network sockets with scatter/gather and
> > > > hardware checksum, maybe?
> > >
> > > afaik those use zero copy already, eg straight pagecache copy.
> >
> > Only if you use sendfile(). And the normal write path uses csum_copy_*
>
> but do those use s/g ?

sendfile yes. sendmsg also when the MTU of the device is larger than a page.

> and hw csum?

sendmsg normally not.

-Andi