Size of mem_section array depends on size of physical address space. In preparation for boot-time switching between paging modes on x86-64 we need to make allocation of mem_section dynamic.
The patch allocates the array on the first call to sparse_memory_present_with_active_regions(). Signed-off-by: Kirill A. Shutemov <[email protected]> --- include/linux/mmzone.h | 2 +- mm/page_alloc.c | 10 ++++++++++ mm/sparse.c | 3 +-- 3 files changed, 12 insertions(+), 3 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index fc14b8b3f6ce..c8eb668eab79 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1137,7 +1137,7 @@ struct mem_section { #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1) #ifdef CONFIG_SPARSEMEM_EXTREME -extern struct mem_section *mem_section[NR_SECTION_ROOTS]; +extern struct mem_section **mem_section; #else extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]; #endif diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 6d30e914afb6..639fd2dce0c4 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5681,6 +5681,16 @@ void __init sparse_memory_present_with_active_regions(int nid) unsigned long start_pfn, end_pfn; int i, this_nid; +#ifdef CONFIG_SPARSEMEM_EXTREME + if (!mem_section) { + unsigned long size, align; + + size = sizeof(struct mem_section) * NR_SECTION_ROOTS; + align = 1 << (INTERNODE_CACHE_SHIFT); + mem_section = memblock_virt_alloc(size, align); + } +#endif + for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, &this_nid) memory_present(this_nid, start_pfn, end_pfn); } diff --git a/mm/sparse.c b/mm/sparse.c index 7b4be3fd5cac..3a226a8c1968 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -22,8 +22,7 @@ * 1) mem_section - memory sections, mem_map's for valid memory */ #ifdef CONFIG_SPARSEMEM_EXTREME -struct mem_section *mem_section[NR_SECTION_ROOTS] - ____cacheline_internodealigned_in_smp; +struct mem_section **mem_section; #else struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT] ____cacheline_internodealigned_in_smp; -- 2.13.2
