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

[David Laight]

From: Christophe Leroy
> 
> 
> Le 03/09/2020 à 17:59, Christoph Hellwig a écrit :
> > Christophe reported a major speedup due to avoiding the iov_iter
> > overhead, so just add this trivial function.  Note that /dev/zero
> > already implements both an iter and non-iter writes so this just
> > makes it more symmetric.
> >
> > Christophe Leroy <christophe.leroy@xxxxxxxxxx>
> > Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> 
> Tested-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>

Any idea what has happened to make the 'iter' version so bad?

	David

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