mirror of
https://github.com/torvalds/linux
synced 2024-09-06 18:01:05 +00:00
![Linus Torvalds](/assets/img/avatar_default.png)
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
261 lines
6.1 KiB
C
261 lines
6.1 KiB
C
/*
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* Generic hugetlb support.
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* (C) William Irwin, April 2004
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*/
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#include <linux/gfp.h>
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#include <linux/list.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/mm.h>
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#include <linux/hugetlb.h>
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#include <linux/sysctl.h>
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#include <linux/highmem.h>
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#include <linux/nodemask.h>
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const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL;
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static unsigned long nr_huge_pages, free_huge_pages;
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unsigned long max_huge_pages;
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static struct list_head hugepage_freelists[MAX_NUMNODES];
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static unsigned int nr_huge_pages_node[MAX_NUMNODES];
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static unsigned int free_huge_pages_node[MAX_NUMNODES];
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static DEFINE_SPINLOCK(hugetlb_lock);
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static void enqueue_huge_page(struct page *page)
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{
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int nid = page_to_nid(page);
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list_add(&page->lru, &hugepage_freelists[nid]);
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free_huge_pages++;
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free_huge_pages_node[nid]++;
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}
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static struct page *dequeue_huge_page(void)
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{
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int nid = numa_node_id();
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struct page *page = NULL;
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if (list_empty(&hugepage_freelists[nid])) {
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for (nid = 0; nid < MAX_NUMNODES; ++nid)
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if (!list_empty(&hugepage_freelists[nid]))
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break;
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}
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if (nid >= 0 && nid < MAX_NUMNODES &&
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!list_empty(&hugepage_freelists[nid])) {
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page = list_entry(hugepage_freelists[nid].next,
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struct page, lru);
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list_del(&page->lru);
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free_huge_pages--;
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free_huge_pages_node[nid]--;
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}
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return page;
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}
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static struct page *alloc_fresh_huge_page(void)
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{
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static int nid = 0;
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struct page *page;
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page = alloc_pages_node(nid, GFP_HIGHUSER|__GFP_COMP|__GFP_NOWARN,
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HUGETLB_PAGE_ORDER);
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nid = (nid + 1) % num_online_nodes();
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if (page) {
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nr_huge_pages++;
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nr_huge_pages_node[page_to_nid(page)]++;
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}
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return page;
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}
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void free_huge_page(struct page *page)
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{
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BUG_ON(page_count(page));
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INIT_LIST_HEAD(&page->lru);
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page[1].mapping = NULL;
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spin_lock(&hugetlb_lock);
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enqueue_huge_page(page);
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spin_unlock(&hugetlb_lock);
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}
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struct page *alloc_huge_page(void)
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{
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struct page *page;
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int i;
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spin_lock(&hugetlb_lock);
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page = dequeue_huge_page();
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if (!page) {
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spin_unlock(&hugetlb_lock);
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return NULL;
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}
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spin_unlock(&hugetlb_lock);
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set_page_count(page, 1);
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page[1].mapping = (void *)free_huge_page;
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for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); ++i)
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clear_highpage(&page[i]);
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return page;
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}
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static int __init hugetlb_init(void)
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{
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unsigned long i;
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struct page *page;
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for (i = 0; i < MAX_NUMNODES; ++i)
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INIT_LIST_HEAD(&hugepage_freelists[i]);
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for (i = 0; i < max_huge_pages; ++i) {
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page = alloc_fresh_huge_page();
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if (!page)
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break;
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spin_lock(&hugetlb_lock);
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enqueue_huge_page(page);
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spin_unlock(&hugetlb_lock);
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}
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max_huge_pages = free_huge_pages = nr_huge_pages = i;
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printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages);
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return 0;
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}
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module_init(hugetlb_init);
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static int __init hugetlb_setup(char *s)
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{
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if (sscanf(s, "%lu", &max_huge_pages) <= 0)
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max_huge_pages = 0;
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return 1;
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}
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__setup("hugepages=", hugetlb_setup);
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#ifdef CONFIG_SYSCTL
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static void update_and_free_page(struct page *page)
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{
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int i;
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nr_huge_pages--;
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nr_huge_pages_node[page_zone(page)->zone_pgdat->node_id]--;
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for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) {
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page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced |
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1 << PG_dirty | 1 << PG_active | 1 << PG_reserved |
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1 << PG_private | 1<< PG_writeback);
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set_page_count(&page[i], 0);
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}
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set_page_count(page, 1);
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__free_pages(page, HUGETLB_PAGE_ORDER);
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}
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#ifdef CONFIG_HIGHMEM
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static void try_to_free_low(unsigned long count)
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{
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int i, nid;
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for (i = 0; i < MAX_NUMNODES; ++i) {
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struct page *page, *next;
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list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) {
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if (PageHighMem(page))
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continue;
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list_del(&page->lru);
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update_and_free_page(page);
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nid = page_zone(page)->zone_pgdat->node_id;
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free_huge_pages--;
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free_huge_pages_node[nid]--;
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if (count >= nr_huge_pages)
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return;
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}
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}
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}
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#else
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static inline void try_to_free_low(unsigned long count)
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{
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}
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#endif
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static unsigned long set_max_huge_pages(unsigned long count)
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{
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while (count > nr_huge_pages) {
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struct page *page = alloc_fresh_huge_page();
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if (!page)
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return nr_huge_pages;
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spin_lock(&hugetlb_lock);
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enqueue_huge_page(page);
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spin_unlock(&hugetlb_lock);
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}
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if (count >= nr_huge_pages)
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return nr_huge_pages;
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spin_lock(&hugetlb_lock);
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try_to_free_low(count);
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while (count < nr_huge_pages) {
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struct page *page = dequeue_huge_page();
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if (!page)
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break;
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update_and_free_page(page);
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}
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spin_unlock(&hugetlb_lock);
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return nr_huge_pages;
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}
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int hugetlb_sysctl_handler(struct ctl_table *table, int write,
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struct file *file, void __user *buffer,
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size_t *length, loff_t *ppos)
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{
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proc_doulongvec_minmax(table, write, file, buffer, length, ppos);
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max_huge_pages = set_max_huge_pages(max_huge_pages);
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return 0;
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}
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#endif /* CONFIG_SYSCTL */
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int hugetlb_report_meminfo(char *buf)
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{
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return sprintf(buf,
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"HugePages_Total: %5lu\n"
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"HugePages_Free: %5lu\n"
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"Hugepagesize: %5lu kB\n",
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nr_huge_pages,
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free_huge_pages,
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HPAGE_SIZE/1024);
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}
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int hugetlb_report_node_meminfo(int nid, char *buf)
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{
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return sprintf(buf,
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"Node %d HugePages_Total: %5u\n"
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"Node %d HugePages_Free: %5u\n",
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nid, nr_huge_pages_node[nid],
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nid, free_huge_pages_node[nid]);
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}
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int is_hugepage_mem_enough(size_t size)
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{
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return (size + ~HPAGE_MASK)/HPAGE_SIZE <= free_huge_pages;
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}
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/* Return the number pages of memory we physically have, in PAGE_SIZE units. */
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unsigned long hugetlb_total_pages(void)
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{
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return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE);
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}
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EXPORT_SYMBOL(hugetlb_total_pages);
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/*
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* We cannot handle pagefaults against hugetlb pages at all. They cause
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* handle_mm_fault() to try to instantiate regular-sized pages in the
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* hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get
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* this far.
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*/
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static struct page *hugetlb_nopage(struct vm_area_struct *vma,
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unsigned long address, int *unused)
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{
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BUG();
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return NULL;
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}
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struct vm_operations_struct hugetlb_vm_ops = {
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.nopage = hugetlb_nopage,
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};
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void zap_hugepage_range(struct vm_area_struct *vma,
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unsigned long start, unsigned long length)
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{
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struct mm_struct *mm = vma->vm_mm;
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spin_lock(&mm->page_table_lock);
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unmap_hugepage_range(vma, start, start + length);
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spin_unlock(&mm->page_table_lock);
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}
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