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Date: Mon, 10 Feb 2014 05:50:01 -0300
From: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
To: Artem Bityutskiy <dedekind1@gmail.com>
Subject: Re: [PATCH 1/1] ubi: Introduce block devices for UBI volumes
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On Mon, Feb 10, 2014 at 10:24:12AM +0200, Artem Bityutskiy wrote:
> On Mon, 2014-02-10 at 05:12 -0300, Ezequiel Garcia wrote:
> > On Mon, Feb 10, 2014 at 08:53:14AM +0100, Richard Weinberger wrote:
> > > Am 10.02.2014 02:29, schrieb Ezequiel Garcia:
> > > >>> +
> > > >>> +               mutex_lock(&dev->vol_mutex);
> > > >>> +               res = do_ubiblock_request(dev, req);
> > > >>> +               mutex_unlock(&dev->vol_mutex);
> > > >>
> > > >> This means that you can never do parallel IO?
> > > >>
> > > > 
> > > > Indeed. Feel free to prepare a follow-up patch improving it,
> > > > once this is merged.
> > > 
> > > Sorry, this is a very lame argument.
> > > 
> > > You need to describe why your application design has this flaw.
> > 
> > Not at all. It's perfectly fine to merge a feature with a simple
> > implementation and improve it progressively. In fact, I've explicitly
> > chosen the simplest implementation whenever possible. We can always
> > get back here and improve the performance.
> 
> The NAND part of the MTD layer serializes all the I/O, so probably it is
> OK. May be needs to be documented, though. May be a comment in the code
> would be nice to have too.
> 

Yes, of course.

[..]
> Would you be able to write a small article for the MTD web site about
> the driver, may be some I/O figures there too, the limitations too? And
> send a patch against mtd-www.git 
> 

Sure!
-- 
Ezequiel García, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com