On 04/23/20 at 08:55am, Mike Rapoport wrote:

On Thu, Apr 23, 2020 at 10:57:20AM +0800, Baoquan He wrote:

quoted

On 04/23/20 at 10:53am, Baoquan He wrote:

quoted

On 04/12/20 at 10:48pm, Mike Rapoport wrote:

quoted

From: Mike Rapoport <redacted>

Some architectures (e.g. ARC) have the ZONE_HIGHMEM zone below the
ZONE_NORMAL. Allowing free_area_init() parse max_zone_pfn array even it is
sorted in descending order allows using free_area_init() on such
architectures.

Add top -> down traversal of max_zone_pfn array in free_area_init() and use
the latter in ARC node/zone initialization.

Or maybe leave ARC as is. The change in this patchset doesn't impact
ARC's handling about zone initialization, leaving it as is can reduce
the complication in implementation of free_area_init(), which is a
common function. So I personally don't see a strong motivation to have
this patch.

OK, seems this patch is prepared to simplify free_area_init_node(), so
take back what I said at above.

Then this looks necessary, even though it introduces special case into
common function free_area_init().

The idea is to have a single free_area_init() for all architectures
without keeping two completely different ways of calculating the zone
extents.
Another thing, is that with this we could eventually switch ARC from
DISCONTIGMEM.

Yeah, I think uniting them into a single free_area_init() is a great
idea. Even though I had been through this patchset, when looked into
each of them, still may forget the detail in later patch :)