Re: [PATCH] ARM: mm: Regarding section when dealing with meminfo

From: Russell King - ARM Linux
Date: Sun Jan 23 2011 - 13:06:10 EST


On Thu, Jan 20, 2011 at 10:11:27AM -0800, Dave Hansen wrote:
> On Thu, 2011-01-20 at 18:01 +0000, Russell King - ARM Linux wrote:
> > > The x86 version of show_mem() actually manages to do this without any
> > > #ifdefs, and works for a ton of configuration options. It uses
> > > pfn_valid() to tell whether it can touch a given pfn.
> >
> > x86 memory layout tends to be very simple as it expects memory to
> > start at the beginning of every region described by a pgdat and extend
> > in one contiguous block. I wish ARM was that simple.
>
> x86 memory layouts can be pretty funky and have been that way for a long
> time. That's why we *have* to handle holes in x86's show_mem(). My
> laptop even has a ~1GB hole in its ZONE_DMA32:

If x86 is soo funky, I suggest you try the x86 version of show_mem()
on an ARM platform with memory holes. Make sure you try it with
sparsemem as well...
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/