#include <linux/pagemap.h>
#include <linux/mempolicy.h>
#include <linux/cpuset.h>
+#include <linux/mutex.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <linux/hugetlb.h>
+#include "internal.h"
const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL;
-static unsigned long nr_huge_pages, free_huge_pages;
+static unsigned long nr_huge_pages, free_huge_pages, resv_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];
-
/*
* Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages
*/
static DEFINE_SPINLOCK(hugetlb_lock);
+static void clear_huge_page(struct page *page, unsigned long addr)
+{
+ int i;
+
+ might_sleep();
+ for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); i++) {
+ cond_resched();
+ clear_user_highpage(page + i, addr);
+ }
+}
+
+static void copy_huge_page(struct page *dst, struct page *src,
+ unsigned long addr)
+{
+ int i;
+
+ might_sleep();
+ for (i = 0; i < HPAGE_SIZE/PAGE_SIZE; i++) {
+ cond_resched();
+ copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE);
+ }
+}
+
static void enqueue_huge_page(struct page *page)
{
int nid = page_to_nid(page);
struct zone **z;
for (z = zonelist->zones; *z; z++) {
- nid = (*z)->zone_pgdat->node_id;
+ nid = zone_to_nid(*z);
if (cpuset_zone_allowed(*z, GFP_HIGHUSER) &&
!list_empty(&hugepage_freelists[nid]))
break;
return page;
}
-static struct page *alloc_fresh_huge_page(void)
+static void free_huge_page(struct page *page)
+{
+ BUG_ON(page_count(page));
+
+ INIT_LIST_HEAD(&page->lru);
+
+ spin_lock(&hugetlb_lock);
+ enqueue_huge_page(page);
+ spin_unlock(&hugetlb_lock);
+}
+
+static int 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();
+ nid = next_node(nid, node_online_map);
+ if (nid == MAX_NUMNODES)
+ nid = first_node(node_online_map);
if (page) {
+ page[1].lru.next = (void *)free_huge_page; /* dtor */
spin_lock(&hugetlb_lock);
nr_huge_pages++;
nr_huge_pages_node[page_to_nid(page)]++;
spin_unlock(&hugetlb_lock);
+ put_page(page); /* free it into the hugepage allocator */
+ return 1;
}
- return page;
-}
-
-void free_huge_page(struct page *page)
-{
- BUG_ON(page_count(page));
-
- INIT_LIST_HEAD(&page->lru);
- page[1].lru.next = NULL; /* reset dtor */
-
- spin_lock(&hugetlb_lock);
- enqueue_huge_page(page);
- spin_unlock(&hugetlb_lock);
+ return 0;
}
-struct page *alloc_huge_page(struct vm_area_struct *vma, unsigned long addr)
+static struct page *alloc_huge_page(struct vm_area_struct *vma,
+ unsigned long addr)
{
struct page *page;
- int i;
spin_lock(&hugetlb_lock);
+ if (vma->vm_flags & VM_MAYSHARE)
+ resv_huge_pages--;
+ else if (free_huge_pages <= resv_huge_pages)
+ goto fail;
+
page = dequeue_huge_page(vma, addr);
- if (!page) {
- spin_unlock(&hugetlb_lock);
- return NULL;
- }
+ if (!page)
+ goto fail;
+
spin_unlock(&hugetlb_lock);
- set_page_count(page, 1);
- page[1].lru.next = (void *)free_huge_page; /* set dtor */
- for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); ++i)
- clear_user_highpage(&page[i], addr);
+ set_page_refcounted(page);
return page;
+
+fail:
+ spin_unlock(&hugetlb_lock);
+ return NULL;
}
static int __init hugetlb_init(void)
{
unsigned long i;
- struct page *page;
if (HPAGE_SHIFT == 0)
return 0;
INIT_LIST_HEAD(&hugepage_freelists[i]);
for (i = 0; i < max_huge_pages; ++i) {
- page = alloc_fresh_huge_page();
- if (!page)
+ if (!alloc_fresh_huge_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);
{
int i;
nr_huge_pages--;
- nr_huge_pages_node[page_zone(page)->zone_pgdat->node_id]--;
+ nr_huge_pages_node[page_to_nid(page)]--;
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);
+ page[1].lru.next = NULL;
+ set_page_refcounted(page);
__free_pages(page, HUGETLB_PAGE_ORDER);
}
#ifdef CONFIG_HIGHMEM
static void try_to_free_low(unsigned long count)
{
- int i, nid;
+ int i;
+
for (i = 0; i < MAX_NUMNODES; ++i) {
struct page *page, *next;
list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) {
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]--;
+ free_huge_pages_node[page_to_nid(page)]--;
if (count >= nr_huge_pages)
return;
}
static unsigned long set_max_huge_pages(unsigned long count)
{
while (count > nr_huge_pages) {
- struct page *page = alloc_fresh_huge_page();
- if (!page)
+ if (!alloc_fresh_huge_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);
+ count = max(count, resv_huge_pages);
try_to_free_low(count);
while (count < nr_huge_pages) {
struct page *page = dequeue_huge_page(NULL, 0);
return sprintf(buf,
"HugePages_Total: %5lu\n"
"HugePages_Free: %5lu\n"
+ "HugePages_Rsvd: %5lu\n"
"Hugepagesize: %5lu kB\n",
nr_huge_pages,
free_huge_pages,
+ resv_huge_pages,
HPAGE_SIZE/1024);
}
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)
{
unsigned long address, pte_t *ptep, pte_t pte)
{
struct page *old_page, *new_page;
- int i, avoidcopy;
+ int avoidcopy;
old_page = pte_page(pte);
}
spin_unlock(&mm->page_table_lock);
- for (i = 0; i < HPAGE_SIZE/PAGE_SIZE; i++)
- copy_user_highpage(new_page + i, old_page + i,
- address + i*PAGE_SIZE);
+ copy_huge_page(new_page, old_page, address);
spin_lock(&mm->page_table_lock);
ptep = huge_pte_offset(mm, address & HPAGE_MASK);
ret = VM_FAULT_OOM;
goto out;
}
+ clear_huge_page(page, address);
if (vma->vm_flags & VM_SHARED) {
int err;
pte_t *ptep;
pte_t entry;
int ret;
+ static DEFINE_MUTEX(hugetlb_instantiation_mutex);
ptep = huge_pte_alloc(mm, address);
if (!ptep)
return VM_FAULT_OOM;
+ /*
+ * Serialize hugepage allocation and instantiation, so that we don't
+ * get spurious allocation failures if two CPUs race to instantiate
+ * the same page in the page cache.
+ */
+ mutex_lock(&hugetlb_instantiation_mutex);
entry = *ptep;
- if (pte_none(entry))
- return hugetlb_no_page(mm, vma, address, ptep, write_access);
+ if (pte_none(entry)) {
+ ret = hugetlb_no_page(mm, vma, address, ptep, write_access);
+ mutex_unlock(&hugetlb_instantiation_mutex);
+ return ret;
+ }
ret = VM_FAULT_MINOR;
if (write_access && !pte_write(entry))
ret = hugetlb_cow(mm, vma, address, ptep, entry);
spin_unlock(&mm->page_table_lock);
+ mutex_unlock(&hugetlb_instantiation_mutex);
return ret;
}
struct page **pages, struct vm_area_struct **vmas,
unsigned long *position, int *length, int i)
{
- unsigned long vpfn, vaddr = *position;
+ unsigned long pfn_offset;
+ unsigned long vaddr = *position;
int remainder = *length;
- vpfn = vaddr/PAGE_SIZE;
spin_lock(&mm->page_table_lock);
while (vaddr < vma->vm_end && remainder) {
pte_t *pte;
break;
}
+ pfn_offset = (vaddr & ~HPAGE_MASK) >> PAGE_SHIFT;
+ page = pte_page(*pte);
+same_page:
if (pages) {
- page = &pte_page(*pte)[vpfn % (HPAGE_SIZE/PAGE_SIZE)];
get_page(page);
- pages[i] = page;
+ pages[i] = page + pfn_offset;
}
if (vmas)
vmas[i] = vma;
vaddr += PAGE_SIZE;
- ++vpfn;
+ ++pfn_offset;
--remainder;
++i;
+ if (vaddr < vma->vm_end && remainder &&
+ pfn_offset < HPAGE_SIZE/PAGE_SIZE) {
+ /*
+ * We use pfn_offset to avoid touching the pageframes
+ * of this compound page.
+ */
+ goto same_page;
+ }
}
spin_unlock(&mm->page_table_lock);
*length = remainder;
return i;
}
+
+void hugetlb_change_protection(struct vm_area_struct *vma,
+ unsigned long address, unsigned long end, pgprot_t newprot)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ unsigned long start = address;
+ pte_t *ptep;
+ pte_t pte;
+
+ BUG_ON(address >= end);
+ flush_cache_range(vma, address, end);
+
+ spin_lock(&mm->page_table_lock);
+ for (; address < end; address += HPAGE_SIZE) {
+ ptep = huge_pte_offset(mm, address);
+ if (!ptep)
+ continue;
+ if (!pte_none(*ptep)) {
+ pte = huge_ptep_get_and_clear(mm, address, ptep);
+ pte = pte_mkhuge(pte_modify(pte, newprot));
+ set_huge_pte_at(mm, address, ptep, pte);
+ lazy_mmu_prot_update(pte);
+ }
+ }
+ spin_unlock(&mm->page_table_lock);
+
+ flush_tlb_range(vma, start, end);
+}
+
+struct file_region {
+ struct list_head link;
+ long from;
+ long to;
+};
+
+static long region_add(struct list_head *head, long f, long t)
+{
+ struct file_region *rg, *nrg, *trg;
+
+ /* Locate the region we are either in or before. */
+ list_for_each_entry(rg, head, link)
+ if (f <= rg->to)
+ break;
+
+ /* Round our left edge to the current segment if it encloses us. */
+ if (f > rg->from)
+ f = rg->from;
+
+ /* Check for and consume any regions we now overlap with. */
+ nrg = rg;
+ list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
+ if (&rg->link == head)
+ break;
+ if (rg->from > t)
+ break;
+
+ /* If this area reaches higher then extend our area to
+ * include it completely. If this is not the first area
+ * which we intend to reuse, free it. */
+ if (rg->to > t)
+ t = rg->to;
+ if (rg != nrg) {
+ list_del(&rg->link);
+ kfree(rg);
+ }
+ }
+ nrg->from = f;
+ nrg->to = t;
+ return 0;
+}
+
+static long region_chg(struct list_head *head, long f, long t)
+{
+ struct file_region *rg, *nrg;
+ long chg = 0;
+
+ /* Locate the region we are before or in. */
+ list_for_each_entry(rg, head, link)
+ if (f <= rg->to)
+ break;
+
+ /* If we are below the current region then a new region is required.
+ * Subtle, allocate a new region at the position but make it zero
+ * size such that we can guarentee to record the reservation. */
+ if (&rg->link == head || t < rg->from) {
+ nrg = kmalloc(sizeof(*nrg), GFP_KERNEL);
+ if (nrg == 0)
+ return -ENOMEM;
+ nrg->from = f;
+ nrg->to = f;
+ INIT_LIST_HEAD(&nrg->link);
+ list_add(&nrg->link, rg->link.prev);
+
+ return t - f;
+ }
+
+ /* Round our left edge to the current segment if it encloses us. */
+ if (f > rg->from)
+ f = rg->from;
+ chg = t - f;
+
+ /* Check for and consume any regions we now overlap with. */
+ list_for_each_entry(rg, rg->link.prev, link) {
+ if (&rg->link == head)
+ break;
+ if (rg->from > t)
+ return chg;
+
+ /* We overlap with this area, if it extends futher than
+ * us then we must extend ourselves. Account for its
+ * existing reservation. */
+ if (rg->to > t) {
+ chg += rg->to - t;
+ t = rg->to;
+ }
+ chg -= rg->to - rg->from;
+ }
+ return chg;
+}
+
+static long region_truncate(struct list_head *head, long end)
+{
+ struct file_region *rg, *trg;
+ long chg = 0;
+
+ /* Locate the region we are either in or before. */
+ list_for_each_entry(rg, head, link)
+ if (end <= rg->to)
+ break;
+ if (&rg->link == head)
+ return 0;
+
+ /* If we are in the middle of a region then adjust it. */
+ if (end > rg->from) {
+ chg = rg->to - end;
+ rg->to = end;
+ rg = list_entry(rg->link.next, typeof(*rg), link);
+ }
+
+ /* Drop any remaining regions. */
+ list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
+ if (&rg->link == head)
+ break;
+ chg += rg->to - rg->from;
+ list_del(&rg->link);
+ kfree(rg);
+ }
+ return chg;
+}
+
+static int hugetlb_acct_memory(long delta)
+{
+ int ret = -ENOMEM;
+
+ spin_lock(&hugetlb_lock);
+ if ((delta + resv_huge_pages) <= free_huge_pages) {
+ resv_huge_pages += delta;
+ ret = 0;
+ }
+ spin_unlock(&hugetlb_lock);
+ return ret;
+}
+
+int hugetlb_reserve_pages(struct inode *inode, long from, long to)
+{
+ long ret, chg;
+
+ chg = region_chg(&inode->i_mapping->private_list, from, to);
+ if (chg < 0)
+ return chg;
+ ret = hugetlb_acct_memory(chg);
+ if (ret < 0)
+ return ret;
+ region_add(&inode->i_mapping->private_list, from, to);
+ return 0;
+}
+
+void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed)
+{
+ long chg = region_truncate(&inode->i_mapping->private_list, offset);
+ hugetlb_acct_memory(freed - chg);
+}