diff options
Diffstat (limited to 'mm/hugetlb.c')
| -rw-r--r-- | mm/hugetlb.c | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c new file mode 100644 index 00000000000..4eb5ae3fbe1 --- /dev/null +++ b/mm/hugetlb.c @@ -0,0 +1,260 @@ +/* + * Generic hugetlb support. + * (C) William Irwin, April 2004 + */ +#include <linux/gfp.h> +#include <linux/list.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/mm.h> +#include <linux/hugetlb.h> +#include <linux/sysctl.h> +#include <linux/highmem.h> +#include <linux/nodemask.h> + +const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; +static unsigned long nr_huge_pages, free_huge_pages; +unsigned long max_huge_pages; +static struct list_head hugepage_freelists[MAX_NUMNODES]; +static unsigned int nr_huge_pages_node[MAX_NUMNODES]; +static unsigned int free_huge_pages_node[MAX_NUMNODES]; +static DEFINE_SPINLOCK(hugetlb_lock); + +static void enqueue_huge_page(struct page *page) +{ + int nid = page_to_nid(page); + list_add(&page->lru, &hugepage_freelists[nid]); + free_huge_pages++; + free_huge_pages_node[nid]++; +} + +static struct page *dequeue_huge_page(void) +{ + int nid = numa_node_id(); + struct page *page = NULL; + + if (list_empty(&hugepage_freelists[nid])) { + for (nid = 0; nid < MAX_NUMNODES; ++nid) + if (!list_empty(&hugepage_freelists[nid])) + break; + } + if (nid >= 0 && nid < MAX_NUMNODES && + !list_empty(&hugepage_freelists[nid])) { + page = list_entry(hugepage_freelists[nid].next, + struct page, lru); + list_del(&page->lru); + free_huge_pages--; + free_huge_pages_node[nid]--; + } + return page; +} + +static struct page *alloc_fresh_huge_page(void) +{ + static int nid = 0; + struct page *page; + page = alloc_pages_node(nid, GFP_HIGHUSER|__GFP_COMP|__GFP_NOWARN, + HUGETLB_PAGE_ORDER); + nid = (nid + 1) % num_online_nodes(); + if (page) { + nr_huge_pages++; + nr_huge_pages_node[page_to_nid(page)]++; + } + return page; +} + +void free_huge_page(struct page *page) +{ + BUG_ON(page_count(page)); + + INIT_LIST_HEAD(&page->lru); + page[1].mapping = NULL; + + spin_lock(&hugetlb_lock); + enqueue_huge_page(page); + spin_unlock(&hugetlb_lock); +} + +struct page *alloc_huge_page(void) +{ + struct page *page; + int i; + + spin_lock(&hugetlb_lock); + page = dequeue_huge_page(); + if (!page) { + spin_unlock(&hugetlb_lock); + return NULL; + } + spin_unlock(&hugetlb_lock); + set_page_count(page, 1); + page[1].mapping = (void *)free_huge_page; + for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); ++i) + clear_highpage(&page[i]); + return page; +} + +static int __init hugetlb_init(void) +{ + unsigned long i; + struct page *page; + + for (i = 0; i < MAX_NUMNODES; ++i) + INIT_LIST_HEAD(&hugepage_freelists[i]); + + for (i = 0; i < max_huge_pages; ++i) { + page = alloc_fresh_huge_page(); + if (!page) + break; + spin_lock(&hugetlb_lock); + enqueue_huge_page(page); + spin_unlock(&hugetlb_lock); + } + max_huge_pages = free_huge_pages = nr_huge_pages = i; + printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages); + return 0; +} +module_init(hugetlb_init); + +static int __init hugetlb_setup(char *s) +{ + if (sscanf(s, "%lu", &max_huge_pages) <= 0) + max_huge_pages = 0; + return 1; +} +__setup("hugepages=", hugetlb_setup); + +#ifdef CONFIG_SYSCTL +static void update_and_free_page(struct page *page) +{ + int i; + nr_huge_pages--; + nr_huge_pages_node[page_zone(page)->zone_pgdat->node_id]--; + for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) { + page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | + 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | + 1 << PG_private | 1<< PG_writeback); + set_page_count(&page[i], 0); + } + set_page_count(page, 1); + __free_pages(page, HUGETLB_PAGE_ORDER); +} + +#ifdef CONFIG_HIGHMEM +static void try_to_free_low(unsigned long count) +{ + int i, nid; + for (i = 0; i < MAX_NUMNODES; ++i) { + struct page *page, *next; + list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) { + if (PageHighMem(page)) + continue; + list_del(&page->lru); + update_and_free_page(page); + nid = page_zone(page)->zone_pgdat->node_id; + free_huge_pages--; + free_huge_pages_node[nid]--; + if (count >= nr_huge_pages) + return; + } + } +} +#else +static inline void try_to_free_low(unsigned long count) +{ +} +#endif + +static unsigned long set_max_huge_pages(unsigned long count) +{ + while (count > nr_huge_pages) { + struct page *page = alloc_fresh_huge_page(); + if (!page) + return nr_huge_pages; + spin_lock(&hugetlb_lock); + enqueue_huge_page(page); + spin_unlock(&hugetlb_lock); + } + if (count >= nr_huge_pages) + return nr_huge_pages; + + spin_lock(&hugetlb_lock); + try_to_free_low(count); + while (count < nr_huge_pages) { + struct page *page = dequeue_huge_page(); + if (!page) + break; + update_and_free_page(page); + } + spin_unlock(&hugetlb_lock); + return nr_huge_pages; +} + +int hugetlb_sysctl_handler(struct ctl_table *table, int write, + struct file *file, void __user *buffer, + size_t *length, loff_t *ppos) +{ + proc_doulongvec_minmax(table, write, file, buffer, length, ppos); + max_huge_pages = set_max_huge_pages(max_huge_pages); + return 0; +} +#endif /* CONFIG_SYSCTL */ + +int hugetlb_report_meminfo(char *buf) +{ + return sprintf(buf, + "HugePages_Total: %5lu\n" + "HugePages_Free: %5lu\n" + "Hugepagesize: %5lu kB\n", + nr_huge_pages, + free_huge_pages, + HPAGE_SIZE/1024); +} + +int hugetlb_report_node_meminfo(int nid, char *buf) +{ + return sprintf(buf, + "Node %d HugePages_Total: %5u\n" + "Node %d HugePages_Free: %5u\n", + nid, nr_huge_pages_node[nid], + nid, free_huge_pages_node[nid]); +} + +int is_hugepage_mem_enough(size_t size) +{ + return (size + ~HPAGE_MASK)/HPAGE_SIZE <= free_huge_pages; +} + +/* Return the number pages of memory we physically have, in PAGE_SIZE units. */ +unsigned long hugetlb_total_pages(void) +{ + return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE); +} +EXPORT_SYMBOL(hugetlb_total_pages); + +/* + * We cannot handle pagefaults against hugetlb pages at all. They cause + * handle_mm_fault() to try to instantiate regular-sized pages in the + * hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get + * this far. + */ +static struct page *hugetlb_nopage(struct vm_area_struct *vma, + unsigned long address, int *unused) +{ + BUG(); + return NULL; +} + +struct vm_operations_struct hugetlb_vm_ops = { + .nopage = hugetlb_nopage, +}; + +void zap_hugepage_range(struct vm_area_struct *vma, + unsigned long start, unsigned long length) +{ + struct mm_struct *mm = vma->vm_mm; + + spin_lock(&mm->page_table_lock); + unmap_hugepage_range(vma, start, start + length); + spin_unlock(&mm->page_table_lock); +} |