Re: [PATCH 02/19] x86, mm: Use big page size for small memory range

From: Yinghai Lu
Date: Mon Oct 22 2012 - 12:33:00 EST

On Mon, Oct 22, 2012 at 7:21 AM, Konrad Rzeszutek Wilk
<konrad@xxxxxxxxxx> wrote:
> On Thu, Oct 18, 2012 at 01:50:12PM -0700, Yinghai Lu wrote:
>> We could map small range in the middle of big range at first, so should use
>> big page size at first to avoid using small page size to break down page table.
>> Only can set big page bit when that range has ram area around it.
> The code looks good.
> I would alter the description to say:
> (Describe the problem)
> "We are wasting entries in the page-table b/c are not taking advantage
> of the fact that adjoining ranges could be of the same type and
> coalescing them together. Instead we end up using the small size type."
> (Explain your patch).
> "We fix this by iterating over the ranges, detecting whether the
> ranges that are next to each other are of the same type - and if so
> set them to our type."

I think my commit change log is clear enough, and will not update it.
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