Re: [PATCH 2/4] mm: cma: Contiguous Memory Allocator added

[Daniel Walker <dwalker@codeaurora.org>]

On Wed, 2010-07-21 at 21:53 +0200, Michał Nazarewicz wrote:
> On Wed, 21 Jul 2010 21:37:09 +0200, Daniel Walker <dwalker@codeaurora.org> wrote:
> > What makes you assume that the bootloader would have these strings?
> > Do your devices have these strings? Maybe mine don't have them.
> 
> I don't assume.  I only state it as one of the possibilities.
> 
> > Assume the strings are gone and you can't find them, or have no idea
> > what they should be. What do you do then?
> 
> Ask Google?

Exactly, that's why they need to be in the kernel ..

> I have a better question for you though: assume the "mem" parameter is
> lost and you have no idea what it should be?  There are many parameters
> passed to kernel by bootloader and you could ask about all of them.

That's hardware based tho. Of course you need info on what your hardware
is. What your doing isn't based on hardware specifics, it's based on
optimizations.

> Passing cma configuration via command line is one of the possibilities
> -- especially convenient during development -- but I would expect platform
> defaults in a final product so you may well not need to worry about it.

I honestly don't thing the "development" angle flies either , but if you
keep this there's no way it should be enabled for anything but debug.

> > Well, I like my kernel minus bloat so that's a good reason. I don't see
> > a good reason to keep the interface in a production situation .. Maybe
> > during development , but really I don't see even a developer needing to
> > make the kind of changes your suggesting very often.
> 
> As I've said, removing the command line parameters would not benefit the
> kernel that much.  It's like 1% of the code or less.  On the other hand,
> it would add complexity to the CMA framework which is a good reason not
> to do that.

If we allowed everyone to add there little tiny bit of bloat where would
we be?

> Would you also argue about removing all the other kernel parameters as
> well? I bet you don't use most of them.  Still they are there because
> removing them would add too much complexity to the code (conditional
> compilation, etc.).

Your is at a different level of complexity ..

Daniel


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