[PATCH 5/5] RISC-V: Implement sparsemem
logang at deltatee.com
Thu Oct 11 11:45:56 PDT 2018
On 2018-10-11 10:24 a.m., Logan Gunthorpe wrote:
> On 2018-10-11 7:37 a.m., Christoph Hellwig wrote:
>>> + * Log2 of the upper bound of the size of a struct page. Used for sizing
>>> + * the vmemmap region only, does not affect actual memory footprint.
>>> + * We don't use sizeof(struct page) directly since taking its size here
>>> + * requires its definition to be available at this point in the inclusion
>>> + * chain, and it may not be a power of 2 in the first place.
>>> + */
>>> +#define STRUCT_PAGE_MAX_SHIFT 6
>> I know this is copied from arm64, but wouldn't this be a good time
>> to move this next to the struct page defintion?
Ok, I spoke too soon...
Having this define next to the struct page definition works great for
riscv. However, making that happen in arm64 seems to be a nightmare. The
include chain in arm64 is tangled up so much that including mm_types
where this is needed seems to be extremely difficult.
Unless you have any ideas, this might not be possible.
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