diff options
Diffstat (limited to 'mm/huge_memory.c')
| -rw-r--r-- | mm/huge_memory.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 5f902e20e8c..04eb489a680 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -47,6 +47,7 @@ static unsigned int khugepaged_scan_sleep_millisecs __read_mostly = 10000; /* during fragmentation poll the hugepage allocator once every minute */ static unsigned int khugepaged_alloc_sleep_millisecs __read_mostly = 60000; static struct task_struct *khugepaged_thread __read_mostly; +static unsigned long huge_zero_pfn __read_mostly; static DEFINE_MUTEX(khugepaged_mutex); static DEFINE_SPINLOCK(khugepaged_mm_lock); static DECLARE_WAIT_QUEUE_HEAD(khugepaged_wait); @@ -159,6 +160,29 @@ static int start_khugepaged(void) return err; } +static int __init init_huge_zero_page(void) +{ + struct page *hpage; + + hpage = alloc_pages((GFP_TRANSHUGE | __GFP_ZERO) & ~__GFP_MOVABLE, + HPAGE_PMD_ORDER); + if (!hpage) + return -ENOMEM; + + huge_zero_pfn = page_to_pfn(hpage); + return 0; +} + +static inline bool is_huge_zero_pfn(unsigned long pfn) +{ + return pfn == huge_zero_pfn; +} + +static inline bool is_huge_zero_pmd(pmd_t pmd) +{ + return is_huge_zero_pfn(pmd_pfn(pmd)); +} + #ifdef CONFIG_SYSFS static ssize_t double_flag_show(struct kobject *kobj, @@ -540,6 +564,10 @@ static int __init hugepage_init(void) if (err) return err; + err = init_huge_zero_page(); + if (err) + goto out; + err = khugepaged_slab_init(); if (err) goto out; @@ -562,6 +590,8 @@ static int __init hugepage_init(void) return 0; out: + if (huge_zero_pfn) + __free_page(pfn_to_page(huge_zero_pfn)); hugepage_exit_sysfs(hugepage_kobj); return err; } |