Re: Why no bigphysarea in mainline?

From: Michael Ellerman
Date: Thu Mar 17 2005 - 22:47:07 EST


On Fri, 18 Mar 2005 01:35, Dave Hansen wrote:
> Doing mem= for drivers isn't just a hack, it's *WRONG*. It's a ticking
> time bomb that magically happens to work on some systems. It will not
> work consistently on a discontiguous memory system, or a memory hotplug
> system.

I couldn't agree more. Problem is I've been asked to change the way mem=X
works on PPC64 so that this hack will work, which is a horrible thought.

> Could you give some examples of drivers which are in the kernel that
> could benefit from this patch? We don't tend to put things like this
> in, unless they have actual users. We don't tend to change code for
> out-of-tree users, either.

No I can't. I've been approached by several "vendors" asking about using mem=X
hacks on PPC64, however I doubt any of them have code in-tree. I'll check
though.

cheers

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