[RFC PATCH 5/6] ARM, mm: change meaning of max_low_pfn to maximum pfn for nobootmem

Joonsoo Kim iamjoonsoo.kim at lge.com
Mon Jul 1 21:28:19 EDT 2013


On Mon, Jul 01, 2013 at 10:14:45AM -0400, Santosh Shilimkar wrote:
> Joonsoo,
> 
> On Monday 25 March 2013 12:11 AM, Joonsoo Kim wrote:
> > nobootmem use max_low_pfn for computing boundary in free_all_bootmem()
> > So we need proper value to max_low_pfn.
> > 
> > But, there is some difficulty related to max_low_pfn. max_low_pfn is used
> > for two meanings in various architectures. One is for number of pages
> > in lowmem and the other is for maximum lowmem pfn. Now, in ARM, it is used
> > as number of pages in lowmem. You can get more information in below link.
> > http://lwn.net/Articles/543408/
> > http://lwn.net/Articles/543424/
> > 
> > As I investigated, architectures which use max_low_pfn as maximum pfn are
> > more than others, so to change meaning of max_low_pfn to maximum pfn
> > is preferable solution to me. This patch change max_low_pfn as maximum
> > lowmem pfn in ARM. In addition, min_low_pfn, max_pfn is assigned according
> > to this criteria.
> > 
> > There is no real user for max_low_pfn except block/blk-setting.c and
> > blk-setting.c assume that max_low_pfn is maximum lowmem pfn,
> > so this patch may not harm anything.
> > 
> > Signed-off-by: Joonsoo Kim <iamjoonsoo.kim at lge.com>
> >
> I have been also carrying similar patch as yours in an attempt
> to make LPAE kernel work on ARM. Your patch carries better
> description, so will your version and include in my series
> which I plan to post on the list after some more testing.
> Will copy you. The changes are very similar to your series.

Okay!

Thanks.
> 
> Regards,
> Santosh
>  
> 
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