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-rw-r--r--mm/hugetlb.c260
1 files changed, 260 insertions, 0 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
new file mode 100644
index 0000000..4eb5ae3
--- /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);
+}
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