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

From: KyongHo Cho
Date: Fri Jan 21 2011 - 06:15:31 EST


On Fri, Jan 21, 2011 at 7:38 PM, Russell King - ARM Linux
<linux@xxxxxxxxxxxxxxxx> wrote:
> On Fri, Jan 21, 2011 at 11:12:27AM +0900, KyongHo Cho wrote:
>> Since the size of section is 256 mib and NR_BANKS is defined as 8,
>> no ARM system can have more RAM than 2GiB in the current implementation.
>> If you want banks in meminfo not to cross sparsemem boundaries,
>> we need to find another way of physical memory specification in the kernel.
>
> There is no problem with increasing NR_BANKS.
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I think it is not reasonable to split a contiguous physical memory
into several chunks.
9 banks are required to use 2 gib.
Even though you think it is no problem,
it becomes a problem when we want to give physical memory information
via booting command line but atag
because there is a restriction in number of characters in booting command line.

I don't understand why larger bank size than the section size is problem.
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