Re: [Linaro-mm-sig] [PATCH 2/9] mm: alloc_contig_freed_pages() added

On Tue, 2011-10-18 at 10:26 -0700, Michal Nazarewicz wrote:

...

You can do this in a more general fashion by checking the zone boundaries and resolving the pfn->page every MAX_ORDER_NR_PAGES. That will not be SPARSEMEM specific.

I've tried doing stuff that way but it ended up with much more code.

I guess instead of:

...

+static inline bool zone_pfn_same_memmap(unsigned long pfn1, unsigned long pfn2) +{

• return pfn_to_section_nr(pfn1) == pfn_to_section_nr(pfn2);

+}

You could do:

static inline bool zone_pfn_same_maxorder(unsigned long pfn1, unsigned long pfn2) { unsigned long mask = MAX_ORDER_NR_PAGES-1; return (pfn1 & mask) == (pfn2 & mask); }

I think that works. Should be the same code you have now, basically.

-- Dave