On 26.07.23 11:57, Aneesh Kumar K V wrote:
On 7/26/23 2:34 PM, David Hildenbrand wrote:
/*
@@ -1310,7 +1400,10 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags)
{
struct mhp_params params = { .pgprot = pgprot_mhp(PAGE_KERNEL) };
enum memblock_flags memblock_flags = MEMBLOCK_NONE;
- struct vmem_altmap mhp_altmap = {};
+ struct vmem_altmap mhp_altmap = {
+ .base_pfn = PHYS_PFN(res->start),
+ .end_pfn = PHYS_PFN(res->end),
Is it required to set .end_pfn, and if so, shouldn't we also set it to
base_pfn + memory_block_memmap_on_memory_pages()) ?
We use that in ppc64 for checking altmap boundary condition. As we
discussed earlier, ppc64 due to vmemmap mapping size restrictions can't
always allocate vmemmap pages from altmap area even if requested. We
fallback to regular memory alocation in that case (only used now with
pmem). We use altmap.end_pfn for that boundary check. You can refer to
altmap_cross_boundary() for more details.
But even then, setting the end to the end of the resource size is wrong, no? We don't want anybody to allocate beyond base_pfn + memory_block_memmap_on_memory_pages().
altmap.end is the end pfn of the resource
Oh, thanks for pointing that out. I wonder why the altmap even has to
care about that ...
--
Cheers,
David / dhildenb
