[PATCH 2/2] powerpc/mm: Increase MAX_PHYSMEM_BITS to 128TB with SPARSEMEM_VMEMMAP config
From: Aneesh Kumar K.V <hidden>
Date: 2018-06-21 08:32:18
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
We do this only with VMEMMAP config so that our page_to_[nid/section] etc are not impacted. Signed-off-by: Aneesh Kumar K.V <redacted> --- arch/powerpc/include/asm/sparsemem.h | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/include/asm/sparsemem.h b/arch/powerpc/include/asm/sparsemem.h
index bc66712bdc3c..28f5dae25db6 100644
--- a/arch/powerpc/include/asm/sparsemem.h
+++ b/arch/powerpc/include/asm/sparsemem.h@@ -6,13 +6,20 @@ #ifdef CONFIG_SPARSEMEM /* * SECTION_SIZE_BITS 2^N: how big each section will be - * MAX_PHYSADDR_BITS 2^N: how much physical address space we have * MAX_PHYSMEM_BITS 2^N: how much memory we can have in that space */ #define SECTION_SIZE_BITS 24 - -#define MAX_PHYSADDR_BITS 46 +/* + * If we store section details in page->flags we can't increase the MAX_PHYSMEM_BITS + * if we increase SECTIONS_WIDTH we will not store node details in page->flags and + * page_to_nid does a page->section->node lookup + * Hence only increase for VMEMMAP. + */ +#ifdef CONFIG_SPARSEMEM_VMEMMAP +#define MAX_PHYSMEM_BITS 47 +#else #define MAX_PHYSMEM_BITS 46 +#endif #endif /* CONFIG_SPARSEMEM */
--
2.17.1