#include <linux/highmem.h>
#include <linux/nodemask.h>
#include <linux/pagemap.h>
+#include <linux/mempolicy.h>
+#include <linux/cpuset.h>
+
#include <asm/page.h>
#include <asm/pgtable.h>
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 enqueue_huge_page(struct page *page)
free_huge_pages_node[nid]++;
}
-static struct page *dequeue_huge_page(void)
+static struct page *dequeue_huge_page(struct vm_area_struct *vma,
+ unsigned long address)
{
int nid = numa_node_id();
struct page *page = NULL;
+ struct zonelist *zonelist = huge_zonelist(vma, address);
+ struct zone **z;
- if (list_empty(&hugepage_freelists[nid])) {
- for (nid = 0; nid < MAX_NUMNODES; ++nid)
- if (!list_empty(&hugepage_freelists[nid]))
- break;
+ for (z = zonelist->zones; *z; z++) {
+ nid = (*z)->zone_pgdat->node_id;
+ if (cpuset_zone_allowed(*z, GFP_HIGHUSER) &&
+ !list_empty(&hugepage_freelists[nid]))
+ break;
}
- if (nid >= 0 && nid < MAX_NUMNODES &&
- !list_empty(&hugepage_freelists[nid])) {
+
+ if (*z) {
page = list_entry(hugepage_freelists[nid].next,
struct page, lru);
list_del(&page->lru);
HUGETLB_PAGE_ORDER);
nid = (nid + 1) % num_online_nodes();
if (page) {
+ spin_lock(&hugetlb_lock);
nr_huge_pages++;
nr_huge_pages_node[page_to_nid(page)]++;
+ spin_unlock(&hugetlb_lock);
}
return page;
}
BUG_ON(page_count(page));
INIT_LIST_HEAD(&page->lru);
- page[1].mapping = NULL;
+ page[1].lru.next = NULL; /* reset dtor */
spin_lock(&hugetlb_lock);
enqueue_huge_page(page);
spin_unlock(&hugetlb_lock);
}
-struct page *alloc_huge_page(void)
+struct page *alloc_huge_page(struct vm_area_struct *vma, unsigned long addr)
{
struct page *page;
int i;
spin_lock(&hugetlb_lock);
- page = dequeue_huge_page();
+ page = dequeue_huge_page(vma, addr);
if (!page) {
spin_unlock(&hugetlb_lock);
return NULL;
}
spin_unlock(&hugetlb_lock);
set_page_count(page, 1);
- page[1].mapping = (void *)free_huge_page;
+ page[1].lru.next = (void *)free_huge_page; /* set dtor */
for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); ++i)
- clear_highpage(&page[i]);
+ clear_user_highpage(&page[i], addr);
return page;
}
spin_lock(&hugetlb_lock);
try_to_free_low(count);
while (count < nr_huge_pages) {
- struct page *page = dequeue_huge_page();
+ struct page *page = dequeue_huge_page(NULL, 0);
if (!page)
break;
update_and_free_page(page);
.nopage = hugetlb_nopage,
};
-static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page)
+static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page,
+ int writable)
{
pte_t entry;
- if (vma->vm_flags & VM_WRITE) {
+ if (writable) {
entry =
pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot)));
} else {
return entry;
}
+static void set_huge_ptep_writable(struct vm_area_struct *vma,
+ unsigned long address, pte_t *ptep)
+{
+ pte_t entry;
+
+ entry = pte_mkwrite(pte_mkdirty(*ptep));
+ ptep_set_access_flags(vma, address, ptep, entry, 1);
+ update_mmu_cache(vma, address, entry);
+ lazy_mmu_prot_update(entry);
+}
+
+
int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
struct vm_area_struct *vma)
{
pte_t *src_pte, *dst_pte, entry;
struct page *ptepage;
unsigned long addr;
+ int cow;
+
+ cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) {
src_pte = huge_pte_offset(src, addr);
spin_lock(&dst->page_table_lock);
spin_lock(&src->page_table_lock);
if (!pte_none(*src_pte)) {
+ if (cow)
+ ptep_set_wrprotect(src, addr, src_pte);
entry = *src_pte;
ptepage = pte_page(entry);
get_page(ptepage);
flush_tlb_range(vma, start, end);
}
-static struct page *find_lock_huge_page(struct address_space *mapping,
- unsigned long idx)
+static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long address, pte_t *ptep, pte_t pte)
{
- struct page *page;
- int err;
- struct inode *inode = mapping->host;
- unsigned long size;
+ struct page *old_page, *new_page;
+ int i, avoidcopy;
-retry:
- page = find_lock_page(mapping, idx);
- if (page)
- goto out;
+ old_page = pte_page(pte);
- /* Check to make sure the mapping hasn't been truncated */
- size = i_size_read(inode) >> HPAGE_SHIFT;
- if (idx >= size)
- goto out;
+ /* If no-one else is actually using this page, avoid the copy
+ * and just make the page writable */
+ avoidcopy = (page_count(old_page) == 1);
+ if (avoidcopy) {
+ set_huge_ptep_writable(vma, address, ptep);
+ return VM_FAULT_MINOR;
+ }
- if (hugetlb_get_quota(mapping))
- goto out;
- page = alloc_huge_page();
- if (!page) {
- hugetlb_put_quota(mapping);
- goto out;
+ page_cache_get(old_page);
+ new_page = alloc_huge_page(vma, address);
+
+ if (!new_page) {
+ page_cache_release(old_page);
+ return VM_FAULT_OOM;
}
- err = add_to_page_cache(page, mapping, idx, GFP_KERNEL);
- if (err) {
- put_page(page);
- hugetlb_put_quota(mapping);
- if (err == -EEXIST)
- goto retry;
- page = NULL;
+ 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);
+ spin_lock(&mm->page_table_lock);
+
+ ptep = huge_pte_offset(mm, address & HPAGE_MASK);
+ if (likely(pte_same(*ptep, pte))) {
+ /* Break COW */
+ set_huge_pte_at(mm, address, ptep,
+ make_huge_pte(vma, new_page, 1));
+ /* Make the old page be freed below */
+ new_page = old_page;
}
-out:
- return page;
+ page_cache_release(new_page);
+ page_cache_release(old_page);
+ return VM_FAULT_MINOR;
}
-int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long address, int write_access)
+int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long address, pte_t *ptep, int write_access)
{
int ret = VM_FAULT_SIGBUS;
unsigned long idx;
unsigned long size;
- pte_t *pte;
struct page *page;
struct address_space *mapping;
-
- pte = huge_pte_alloc(mm, address);
- if (!pte)
- goto out;
+ pte_t new_pte;
mapping = vma->vm_file->f_mapping;
idx = ((address - vma->vm_start) >> HPAGE_SHIFT)
* Use page lock to guard against racing truncation
* before we get page_table_lock.
*/
- page = find_lock_huge_page(mapping, idx);
- if (!page)
- goto out;
+retry:
+ page = find_lock_page(mapping, idx);
+ if (!page) {
+ if (hugetlb_get_quota(mapping))
+ goto out;
+ page = alloc_huge_page(vma, address);
+ if (!page) {
+ hugetlb_put_quota(mapping);
+ ret = VM_FAULT_OOM;
+ goto out;
+ }
+
+ if (vma->vm_flags & VM_SHARED) {
+ int err;
+
+ err = add_to_page_cache(page, mapping, idx, GFP_KERNEL);
+ if (err) {
+ put_page(page);
+ hugetlb_put_quota(mapping);
+ if (err == -EEXIST)
+ goto retry;
+ goto out;
+ }
+ } else
+ lock_page(page);
+ }
spin_lock(&mm->page_table_lock);
size = i_size_read(mapping->host) >> HPAGE_SHIFT;
goto backout;
ret = VM_FAULT_MINOR;
- if (!pte_none(*pte))
+ if (!pte_none(*ptep))
goto backout;
add_mm_counter(mm, file_rss, HPAGE_SIZE / PAGE_SIZE);
- set_huge_pte_at(mm, address, pte, make_huge_pte(vma, page));
+ new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE)
+ && (vma->vm_flags & VM_SHARED)));
+ set_huge_pte_at(mm, address, ptep, new_pte);
+
+ if (write_access && !(vma->vm_flags & VM_SHARED)) {
+ /* Optimization, do the COW without a second fault */
+ ret = hugetlb_cow(mm, vma, address, ptep, new_pte);
+ }
+
spin_unlock(&mm->page_table_lock);
unlock_page(page);
out:
goto out;
}
+int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long address, int write_access)
+{
+ pte_t *ptep;
+ pte_t entry;
+ int ret;
+
+ ptep = huge_pte_alloc(mm, address);
+ if (!ptep)
+ return VM_FAULT_OOM;
+
+ entry = *ptep;
+ if (pte_none(entry))
+ return hugetlb_no_page(mm, vma, address, ptep, write_access);
+
+ ret = VM_FAULT_MINOR;
+
+ spin_lock(&mm->page_table_lock);
+ /* Check for a racing update before calling hugetlb_cow */
+ if (likely(pte_same(entry, *ptep)))
+ if (write_access && !pte_write(entry))
+ ret = hugetlb_cow(mm, vma, address, ptep, entry);
+ spin_unlock(&mm->page_table_lock);
+
+ return ret;
+}
+
int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
struct page **pages, struct vm_area_struct **vmas,
unsigned long *position, int *length, int i)
git.openpandora.org / pandora-kernel.git / blobdiff