[PATCH 07/13] ia64: make SPARSEMEM default and disable DISCONTIGMEM

[Guenter Roeck]

On Tue, Oct 27, 2020 at 01:29:49PM +0200, Mike Rapoport wrote:
> From: Mike Rapoport <rppt at linux.ibm.com>
> 
> SPARSEMEM memory model suitable for systems with large holes in their
> phyiscal memory layout. With SPARSEMEM_VMEMMAP enabled it provides
> pfn_to_page() and page_to_pfn() as fast as FLATMEM.
> 
> Make it the default memory model for IA-64 and disable DISCONTIGMEM which
> is considered obsolete for quite some time.
> 
> Signed-off-by: Mike Rapoport <rppt at linux.ibm.com>

This patch results in 

include/linux/mmzone.h:1156:2: error: #error Allocator MAX_ORDER exceeds SECTION_SIZE
 1156 | #error Allocator MAX_ORDER exceeds SECTION_SIZE

when building ia64:defconfig.

Also, PAGE_SHIFT is not defined, though I don't know if that is related.

Reverting the patch fixes the problem for me.

Guenter

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# bad: [46aa09d885ce303efd6444def783ec575a5b57ee] mm, page_poison: remove CONFIG_PAGE_POISONING_ZERO
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# bad: [e0287fb91c006d12bed9e6fbfc7fe661ad7f9647] mm,hwpoison: disable pcplists before grabbing a refcount
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# good: [7499e1e91e18a285274e9b761ba2abf21e4343fa] mm/vmalloc: use free_vm_area() if an allocation fails
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# first bad commit: [94d171d065be406a2407f0d723afe14c05526283] ia64: make SPARSEMEM default and disable DISCONTIGMEM