Re: [PATCH v2] /dev/zero: also implement ->read

From: Christoph Hellwig
Date: Mon Sep 07 2020 - 04:21:45 EST


On Mon, Sep 07, 2020 at 10:21:14AM +0200, Greg KH wrote:
> On Mon, Sep 07, 2020 at 09:51:43AM +0200, Christoph Hellwig wrote:
> > Christophe reported a major speedup due to avoiding the iov_iter
> > overhead, so just add this trivial function.
> >
> > Suggested-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
> > Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> > Tested-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
> > ---
> >
> > Changes since v1:
> > - fix the Suggested-by: tag
> > - report the actually read bytes in case of a partial clear_user
> > - remove an impossible to hit conditional
> >
> > drivers/char/mem.c | 28 ++++++++++++++++++++++++++++
> > 1 file changed, 28 insertions(+)
>
> I already merged your v1 into my tree, do you want me to revert that and
> then add this, or can you send me the diff to apply instead? I can't
> rebase my public trees.

Sure, I can send an incremental one. I vaguely remembered you as one
of the quilt holdouts.