Date: Thu, 23 Feb 2006 00:56:39 +0100
From: Pavel Machek <pavel@suse.cz>
To: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Nigel Cunningham <ncunningham@cyclades.com>,
       Dmitry Torokhov <dtor_core@ameritech.net>,
       Andreas Happe <andreashappe@snikt.net>, linux-kernel@vger.kernel.org,
       Suspend2 Devel List <suspend2-devel@lists.suspend2.net>
Subject: Re: Which is simpler? (Was Re: [Suspend2-devel] Re: [ 00/10] [Suspend2] Modules support.)
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Hi!

> > > > It is doable - I'm doing it now, but am thinking about reverting part of the 
> > > > code to use pbes again. If you're going to look at using bitmaps in place of 
> > > > pbes, me changing would be a waste of time. Do you want me to hold off for a 
> > > > while? (I'll happily do that, as I have far more than enough to keep me 
> > > > occupied at the moment anyway).
> > > 
> > > Well, I'd say so. :-)
> > > 
> > > Frankly, I didn't think of dropping PBEs right now, but in the long run
> > > that's worth considering, IMO.  The advantage of PBEs is that they are easy to
> > > handle in the assembly parts, but apart from this they are a bit wasteful
> > > (not very much, though).
> > 
> > Of course it will depend on what patch looks like, but changing
> > assembly parts is hard -- you have to change all the architectures,
> > and better not make any mistake.
> 
> Yes, that would be a lot of work, so it's rather a long term
> "vision".

Ok, I have no problems with visions.

> I think we should try to get the pagecache stuff right first anyway.

Are you sure it is worth doing? I mean... it only helps on small
machines, no?

OTOH having it for benchmarks will be nice, and perhaps we could use
that kind it to speed up boot and similar things... 

> > > The fact that we use page flags to store some suspend/resume-related
> > > information is a big disadvantage in my view, and I'd like to get rid of that
> > > in the future.  In principle we could use a bitmap, or rather two of them,
> > > to store the same information independently of the page flags, and
> > > if we use bitmaps for this purpose, we can use them also instead of
> > > PBEs.
> > 
> > Well, we "only" use 2 bits... :-).
> 
> In my view the problem is this adds constraints that other people have to take
> into account.  Not a good thing if avoidable IMHO.

Well, I hope that swsusp development will move to userland in future
:-).
									Pavel
-- 
Web maintainer for suspend.sf.net (www.sf.net/projects/suspend) wanted...
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