diff options
| -rw-r--r-- | include/linux/memblock.h | 1 | ||||
| -rw-r--r-- | mm/memblock.c | 17 | ||||
| -rw-r--r-- | tools/include/linux/pfn.h | 1 |
3 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/memblock.h b/include/linux/memblock.h index fc4d75c6cec3..673d5cae7c81 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -467,6 +467,7 @@ static inline __init_memblock bool memblock_bottom_up(void) phys_addr_t memblock_phys_mem_size(void); phys_addr_t memblock_reserved_size(void); +unsigned long memblock_estimated_nr_free_pages(void); phys_addr_t memblock_start_of_DRAM(void); phys_addr_t memblock_end_of_DRAM(void); void memblock_enforce_memory_limit(phys_addr_t memory_limit); diff --git a/mm/memblock.c b/mm/memblock.c index 3b9dc2d89b8a..213057603b65 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -1731,6 +1731,23 @@ phys_addr_t __init_memblock memblock_reserved_size(void) return memblock.reserved.total_size; } +/** + * memblock_estimated_nr_free_pages - return estimated number of free pages + * from memblock point of view + * + * During bootup, subsystems might need a rough estimate of the number of free + * pages in the whole system, before precise numbers are available from the + * buddy. Especially with CONFIG_DEFERRED_STRUCT_PAGE_INIT, the numbers + * obtained from the buddy might be very imprecise during bootup. + * + * Return: + * An estimated number of free pages from memblock point of view. + */ +unsigned long __init memblock_estimated_nr_free_pages(void) +{ + return PHYS_PFN(memblock_phys_mem_size() - memblock_reserved_size()); +} + /* lowest address */ phys_addr_t __init_memblock memblock_start_of_DRAM(void) { diff --git a/tools/include/linux/pfn.h b/tools/include/linux/pfn.h index 7512a58189eb..f77a30d70152 100644 --- a/tools/include/linux/pfn.h +++ b/tools/include/linux/pfn.h @@ -7,4 +7,5 @@ #define PFN_UP(x) (((x) + PAGE_SIZE - 1) >> PAGE_SHIFT) #define PFN_DOWN(x) ((x) >> PAGE_SHIFT) #define PFN_PHYS(x) ((phys_addr_t)(x) << PAGE_SHIFT) +#define PHYS_PFN(x) ((unsigned long)((x) >> PAGE_SHIFT)) #endif |