Re: bmap/strategy for vnd backing file

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Wed, Sep 19, 2018 at 12:08:02AM +0200, Emmanuel Dreyfus wrote:
> Manuel Bouyer <bouyer%antioche.eu.org@localhost> wrote:
> 
> > > The code in sys/dev/vnd.c is abls to handle I/O either using
> > > bmap/strategy, or using read/write. The later is more efficient,
> > 
> > that's clearly not true. There have been a thread on this topic recently.
> > Or maybe you mean "the former" ?
> 
> Yes, I meant "the former". As I understand, using read/write will in the
> end use bmap/strategy but with the overhead of more layers, is that
> right?

Yes, it will probably end up using bmap/strategy, but with much more I/Os
as it may do read/modify/write cycles.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--