}
/*
+ * Return the size of the pages allocated when backing a VMA. In the majority
+ * cases this will be same size as used by the page table entries.
+ */
+unsigned long vma_kernel_pagesize(struct vm_area_struct *vma)
+{
+ struct hstate *hstate;
+
+ if (!is_vm_hugetlb_page(vma))
+ return PAGE_SIZE;
+
+ hstate = hstate_vma(vma);
+
+ return 1UL << (hstate->order + PAGE_SHIFT);
+}
+EXPORT_SYMBOL_GPL(vma_kernel_pagesize);
+
+/*
+ * Return the page size being used by the MMU to back a VMA. In the majority
+ * of cases, the page size used by the kernel matches the MMU size. On
+ * architectures where it differs, an architecture-specific version of this
+ * function is required.
+ */
+#ifndef vma_mmu_pagesize
+unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
+{
+ return vma_kernel_pagesize(vma);
+}
+#endif
+
+/*
* Flags for MAP_PRIVATE reservations. These are stored in the bottom
* bits of the reservation map pointer, which are always clear due to
* alignment.
static struct resv_map *vma_resv_map(struct vm_area_struct *vma)
{
VM_BUG_ON(!is_vm_hugetlb_page(vma));
- if (!(vma->vm_flags & VM_SHARED))
+ if (!(vma->vm_flags & VM_MAYSHARE))
return (struct resv_map *)(get_vma_private_data(vma) &
~HPAGE_RESV_MASK);
return NULL;
static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map)
{
VM_BUG_ON(!is_vm_hugetlb_page(vma));
- VM_BUG_ON(vma->vm_flags & VM_SHARED);
+ VM_BUG_ON(vma->vm_flags & VM_MAYSHARE);
set_vma_private_data(vma, (get_vma_private_data(vma) &
HPAGE_RESV_MASK) | (unsigned long)map);
static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags)
{
VM_BUG_ON(!is_vm_hugetlb_page(vma));
- VM_BUG_ON(vma->vm_flags & VM_SHARED);
+ VM_BUG_ON(vma->vm_flags & VM_MAYSHARE);
set_vma_private_data(vma, get_vma_private_data(vma) | flags);
}
if (vma->vm_flags & VM_NORESERVE)
return;
- if (vma->vm_flags & VM_SHARED) {
+ if (vma->vm_flags & VM_MAYSHARE) {
/* Shared mappings always use reserves */
h->resv_huge_pages--;
} else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
void reset_vma_resv_huge_pages(struct vm_area_struct *vma)
{
VM_BUG_ON(!is_vm_hugetlb_page(vma));
- if (!(vma->vm_flags & VM_SHARED))
+ if (!(vma->vm_flags & VM_MAYSHARE))
vma->vm_private_data = (void *)0;
}
/* Returns true if the VMA has associated reserve pages */
static int vma_has_reserves(struct vm_area_struct *vma)
{
- if (vma->vm_flags & VM_SHARED)
+ if (vma->vm_flags & VM_MAYSHARE)
return 1;
if (is_vma_resv_set(vma, HPAGE_RESV_OWNER))
return 1;
return 0;
}
+static void clear_gigantic_page(struct page *page,
+ unsigned long addr, unsigned long sz)
+{
+ int i;
+ struct page *p = page;
+
+ might_sleep();
+ for (i = 0; i < sz/PAGE_SIZE; i++, p = mem_map_next(p, page, i)) {
+ cond_resched();
+ clear_user_highpage(p, addr + i * PAGE_SIZE);
+ }
+}
static void clear_huge_page(struct page *page,
unsigned long addr, unsigned long sz)
{
int i;
+ if (unlikely(sz > MAX_ORDER_NR_PAGES)) {
+ clear_gigantic_page(page, addr, sz);
+ return;
+ }
+
might_sleep();
for (i = 0; i < sz/PAGE_SIZE; i++) {
cond_resched();
}
}
+static void copy_gigantic_page(struct page *dst, struct page *src,
+ unsigned long addr, struct vm_area_struct *vma)
+{
+ int i;
+ struct hstate *h = hstate_vma(vma);
+ struct page *dst_base = dst;
+ struct page *src_base = src;
+ might_sleep();
+ for (i = 0; i < pages_per_huge_page(h); ) {
+ cond_resched();
+ copy_user_highpage(dst, src, addr + i*PAGE_SIZE, vma);
+
+ i++;
+ dst = mem_map_next(dst, dst_base, i);
+ src = mem_map_next(src, src_base, i);
+ }
+}
static void copy_huge_page(struct page *dst, struct page *src,
unsigned long addr, struct vm_area_struct *vma)
{
int i;
struct hstate *h = hstate_vma(vma);
+ if (unlikely(pages_per_huge_page(h) > MAX_ORDER_NR_PAGES)) {
+ copy_gigantic_page(dst, src, addr, vma);
+ return;
+ }
+
might_sleep();
for (i = 0; i < pages_per_huge_page(h); i++) {
cond_resched();
h->free_huge_pages_node[nid]++;
}
-static struct page *dequeue_huge_page(struct hstate *h)
-{
- int nid;
- struct page *page = NULL;
-
- for (nid = 0; nid < MAX_NUMNODES; ++nid) {
- if (!list_empty(&h->hugepage_freelists[nid])) {
- page = list_entry(h->hugepage_freelists[nid].next,
- struct page, lru);
- list_del(&page->lru);
- h->free_huge_pages--;
- h->free_huge_pages_node[nid]--;
- break;
- }
- }
- return page;
-}
-
static struct page *dequeue_huge_page_vma(struct hstate *h,
struct vm_area_struct *vma,
unsigned long address, int avoid_reserve)
{
int i;
+ VM_BUG_ON(h->order >= MAX_ORDER);
+
h->nr_huge_pages--;
h->nr_huge_pages_node[page_to_nid(page)]--;
for (i = 0; i < pages_per_huge_page(h); i++) {
hugetlb_put_quota(mapping, 1);
}
-/*
- * Increment or decrement surplus_huge_pages. Keep node-specific counters
- * balanced by operating on them in a round-robin fashion.
- * Returns 1 if an adjustment was made.
- */
-static int adjust_pool_surplus(struct hstate *h, int delta)
-{
- static int prev_nid;
- int nid = prev_nid;
- int ret = 0;
-
- VM_BUG_ON(delta != -1 && delta != 1);
- do {
- nid = next_node(nid, node_online_map);
- if (nid == MAX_NUMNODES)
- nid = first_node(node_online_map);
-
- /* To shrink on this node, there must be a surplus page */
- if (delta < 0 && !h->surplus_huge_pages_node[nid])
- continue;
- /* Surplus cannot exceed the total number of pages */
- if (delta > 0 && h->surplus_huge_pages_node[nid] >=
- h->nr_huge_pages_node[nid])
- continue;
-
- h->surplus_huge_pages += delta;
- h->surplus_huge_pages_node[nid] += delta;
- ret = 1;
- break;
- } while (nid != prev_nid);
-
- prev_nid = nid;
- return ret;
-}
-
static void prep_new_huge_page(struct hstate *h, struct page *page, int nid)
{
set_compound_page_dtor(page, free_huge_page);
put_page(page); /* free it into the hugepage allocator */
}
+static void prep_compound_gigantic_page(struct page *page, unsigned long order)
+{
+ int i;
+ int nr_pages = 1 << order;
+ struct page *p = page + 1;
+
+ /* we rely on prep_new_huge_page to set the destructor */
+ set_compound_order(page, order);
+ __SetPageHead(page);
+ for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) {
+ __SetPageTail(p);
+ p->first_page = page;
+ }
+}
+
+int PageHuge(struct page *page)
+{
+ compound_page_dtor *dtor;
+
+ if (!PageCompound(page))
+ return 0;
+
+ page = compound_head(page);
+ dtor = get_compound_page_dtor(page);
+
+ return dtor == free_huge_page;
+}
+
static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid)
{
struct page *page;
if (h->order >= MAX_ORDER)
return NULL;
- page = alloc_pages_node(nid,
+ page = alloc_pages_exact_node(nid,
htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|
__GFP_REPEAT|__GFP_NOWARN,
huge_page_order(h));
/*
* Use a helper variable to find the next node and then
- * copy it back to hugetlb_next_nid afterwards:
+ * copy it back to next_nid_to_alloc afterwards:
* otherwise there's a window in which a racer might
- * pass invalid nid MAX_NUMNODES to alloc_pages_node.
+ * pass invalid nid MAX_NUMNODES to alloc_pages_exact_node.
* But we don't need to use a spin_lock here: it really
* doesn't matter if occasionally a racer chooses the
* same nid as we do. Move nid forward in the mask even
* if we just successfully allocated a hugepage so that
* the next caller gets hugepages on the next node.
*/
-static int hstate_next_node(struct hstate *h)
+static int hstate_next_node_to_alloc(struct hstate *h)
{
int next_nid;
- next_nid = next_node(h->hugetlb_next_nid, node_online_map);
+ next_nid = next_node(h->next_nid_to_alloc, node_online_map);
if (next_nid == MAX_NUMNODES)
next_nid = first_node(node_online_map);
- h->hugetlb_next_nid = next_nid;
+ h->next_nid_to_alloc = next_nid;
return next_nid;
}
int next_nid;
int ret = 0;
- start_nid = h->hugetlb_next_nid;
+ start_nid = h->next_nid_to_alloc;
+ next_nid = start_nid;
do {
- page = alloc_fresh_huge_page_node(h, h->hugetlb_next_nid);
+ page = alloc_fresh_huge_page_node(h, next_nid);
if (page)
ret = 1;
- next_nid = hstate_next_node(h);
- } while (!page && h->hugetlb_next_nid != start_nid);
+ next_nid = hstate_next_node_to_alloc(h);
+ } while (!page && next_nid != start_nid);
if (ret)
count_vm_event(HTLB_BUDDY_PGALLOC);
return ret;
}
+/*
+ * helper for free_pool_huge_page() - find next node
+ * from which to free a huge page
+ */
+static int hstate_next_node_to_free(struct hstate *h)
+{
+ int next_nid;
+ next_nid = next_node(h->next_nid_to_free, node_online_map);
+ if (next_nid == MAX_NUMNODES)
+ next_nid = first_node(node_online_map);
+ h->next_nid_to_free = next_nid;
+ return next_nid;
+}
+
+/*
+ * Free huge page from pool from next node to free.
+ * Attempt to keep persistent huge pages more or less
+ * balanced over allowed nodes.
+ * Called with hugetlb_lock locked.
+ */
+static int free_pool_huge_page(struct hstate *h, bool acct_surplus)
+{
+ int start_nid;
+ int next_nid;
+ int ret = 0;
+
+ start_nid = h->next_nid_to_free;
+ next_nid = start_nid;
+
+ do {
+ /*
+ * If we're returning unused surplus pages, only examine
+ * nodes with surplus pages.
+ */
+ if ((!acct_surplus || h->surplus_huge_pages_node[next_nid]) &&
+ !list_empty(&h->hugepage_freelists[next_nid])) {
+ struct page *page =
+ list_entry(h->hugepage_freelists[next_nid].next,
+ struct page, lru);
+ list_del(&page->lru);
+ h->free_huge_pages--;
+ h->free_huge_pages_node[next_nid]--;
+ if (acct_surplus) {
+ h->surplus_huge_pages--;
+ h->surplus_huge_pages_node[next_nid]--;
+ }
+ update_and_free_page(h, page);
+ ret = 1;
+ }
+ next_nid = hstate_next_node_to_free(h);
+ } while (!ret && next_nid != start_nid);
+
+ return ret;
+}
+
static struct page *alloc_buddy_huge_page(struct hstate *h,
struct vm_area_struct *vma, unsigned long address)
{
* When releasing a hugetlb pool reservation, any surplus pages that were
* allocated to satisfy the reservation must be explicitly freed if they were
* never used.
+ * Called with hugetlb_lock held.
*/
static void return_unused_surplus_pages(struct hstate *h,
unsigned long unused_resv_pages)
{
- static int nid = -1;
- struct page *page;
unsigned long nr_pages;
- /*
- * We want to release as many surplus pages as possible, spread
- * evenly across all nodes. Iterate across all nodes until we
- * can no longer free unreserved surplus pages. This occurs when
- * the nodes with surplus pages have no free pages.
- */
- unsigned long remaining_iterations = num_online_nodes();
-
/* Uncommit the reservation */
h->resv_huge_pages -= unused_resv_pages;
nr_pages = min(unused_resv_pages, h->surplus_huge_pages);
- while (remaining_iterations-- && nr_pages) {
- nid = next_node(nid, node_online_map);
- if (nid == MAX_NUMNODES)
- nid = first_node(node_online_map);
-
- if (!h->surplus_huge_pages_node[nid])
- continue;
-
- if (!list_empty(&h->hugepage_freelists[nid])) {
- page = list_entry(h->hugepage_freelists[nid].next,
- struct page, lru);
- list_del(&page->lru);
- update_and_free_page(h, page);
- h->free_huge_pages--;
- h->free_huge_pages_node[nid]--;
- h->surplus_huge_pages--;
- h->surplus_huge_pages_node[nid]--;
- nr_pages--;
- remaining_iterations = num_online_nodes();
- }
+ /*
+ * We want to release as many surplus pages as possible, spread
+ * evenly across all nodes. Iterate across all nodes until we
+ * can no longer free unreserved surplus pages. This occurs when
+ * the nodes with surplus pages have no free pages.
+ * free_pool_huge_page() will balance the the frees across the
+ * on-line nodes for us and will handle the hstate accounting.
+ */
+ while (nr_pages--) {
+ if (!free_pool_huge_page(h, 1))
+ break;
}
}
* an instantiated the change should be committed via vma_commit_reservation.
* No action is required on failure.
*/
-static int vma_needs_reservation(struct hstate *h,
+static long vma_needs_reservation(struct hstate *h,
struct vm_area_struct *vma, unsigned long addr)
{
struct address_space *mapping = vma->vm_file->f_mapping;
struct inode *inode = mapping->host;
- if (vma->vm_flags & VM_SHARED) {
+ if (vma->vm_flags & VM_MAYSHARE) {
pgoff_t idx = vma_hugecache_offset(h, vma, addr);
return region_chg(&inode->i_mapping->private_list,
idx, idx + 1);
return 1;
} else {
- int err;
+ long err;
pgoff_t idx = vma_hugecache_offset(h, vma, addr);
struct resv_map *reservations = vma_resv_map(vma);
struct address_space *mapping = vma->vm_file->f_mapping;
struct inode *inode = mapping->host;
- if (vma->vm_flags & VM_SHARED) {
+ if (vma->vm_flags & VM_MAYSHARE) {
pgoff_t idx = vma_hugecache_offset(h, vma, addr);
region_add(&inode->i_mapping->private_list, idx, idx + 1);
struct page *page;
struct address_space *mapping = vma->vm_file->f_mapping;
struct inode *inode = mapping->host;
- unsigned int chg;
+ long chg;
/*
* Processes that did not create the mapping will have no reserves and
return page;
}
-__attribute__((weak)) int alloc_bootmem_huge_page(struct hstate *h)
+int __weak alloc_bootmem_huge_page(struct hstate *h)
{
struct huge_bootmem_page *m;
int nr_nodes = nodes_weight(node_online_map);
void *addr;
addr = __alloc_bootmem_node_nopanic(
- NODE_DATA(h->hugetlb_next_nid),
+ NODE_DATA(h->next_nid_to_alloc),
huge_page_size(h), huge_page_size(h), 0);
+ hstate_next_node_to_alloc(h);
if (addr) {
/*
* Use the beginning of the huge page to store the
* puts them into the mem_map).
*/
m = addr;
- if (m)
- goto found;
+ goto found;
}
- hstate_next_node(h);
nr_nodes--;
}
return 0;
return 1;
}
+static void prep_compound_huge_page(struct page *page, int order)
+{
+ if (unlikely(order > (MAX_ORDER - 1)))
+ prep_compound_gigantic_page(page, order);
+ else
+ prep_compound_page(page, order);
+}
+
/* Put bootmem huge pages into the standard lists after mem_map is up */
static void __init gather_bootmem_prealloc(void)
{
struct hstate *h = m->hstate;
__ClearPageReserved(page);
WARN_ON(page_count(page) != 1);
- prep_compound_page(page, h->order);
+ prep_compound_huge_page(page, h->order);
prep_new_huge_page(h, page, page_to_nid(page));
}
}
}
#endif
+/*
+ * Increment or decrement surplus_huge_pages. Keep node-specific counters
+ * balanced by operating on them in a round-robin fashion.
+ * Returns 1 if an adjustment was made.
+ */
+static int adjust_pool_surplus(struct hstate *h, int delta)
+{
+ int start_nid, next_nid;
+ int ret = 0;
+
+ VM_BUG_ON(delta != -1 && delta != 1);
+
+ if (delta < 0)
+ start_nid = h->next_nid_to_alloc;
+ else
+ start_nid = h->next_nid_to_free;
+ next_nid = start_nid;
+
+ do {
+ int nid = next_nid;
+ if (delta < 0) {
+ next_nid = hstate_next_node_to_alloc(h);
+ /*
+ * To shrink on this node, there must be a surplus page
+ */
+ if (!h->surplus_huge_pages_node[nid])
+ continue;
+ }
+ if (delta > 0) {
+ next_nid = hstate_next_node_to_free(h);
+ /*
+ * Surplus cannot exceed the total number of pages
+ */
+ if (h->surplus_huge_pages_node[nid] >=
+ h->nr_huge_pages_node[nid])
+ continue;
+ }
+
+ h->surplus_huge_pages += delta;
+ h->surplus_huge_pages_node[nid] += delta;
+ ret = 1;
+ break;
+ } while (next_nid != start_nid);
+
+ return ret;
+}
+
#define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages)
static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count)
{
min_count = max(count, min_count);
try_to_free_low(h, min_count);
while (min_count < persistent_huge_pages(h)) {
- struct page *page = dequeue_huge_page(h);
- if (!page)
+ if (!free_pool_huge_page(h, 0))
break;
- update_and_free_page(h, page);
}
while (count < persistent_huge_pages(h)) {
if (!adjust_pool_surplus(h, 1))
h->free_huge_pages = 0;
for (i = 0; i < MAX_NUMNODES; ++i)
INIT_LIST_HEAD(&h->hugepage_freelists[i]);
- h->hugetlb_next_nid = first_node(node_online_map);
+ h->next_nid_to_alloc = first_node(node_online_map);
+ h->next_nid_to_free = first_node(node_online_map);
snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB",
huge_page_size(h)/1024);
#ifdef CONFIG_SYSCTL
int hugetlb_sysctl_handler(struct ctl_table *table, int write,
- struct file *file, void __user *buffer,
+ void __user *buffer,
size_t *length, loff_t *ppos)
{
struct hstate *h = &default_hstate;
table->data = &tmp;
table->maxlen = sizeof(unsigned long);
- proc_doulongvec_minmax(table, write, file, buffer, length, ppos);
+ proc_doulongvec_minmax(table, write, buffer, length, ppos);
if (write)
h->max_huge_pages = set_max_huge_pages(h, tmp);
}
int hugetlb_treat_movable_handler(struct ctl_table *table, int write,
- struct file *file, void __user *buffer,
+ void __user *buffer,
size_t *length, loff_t *ppos)
{
- proc_dointvec(table, write, file, buffer, length, ppos);
+ proc_dointvec(table, write, buffer, length, ppos);
if (hugepages_treat_as_movable)
htlb_alloc_mask = GFP_HIGHUSER_MOVABLE;
else
}
int hugetlb_overcommit_handler(struct ctl_table *table, int write,
- struct file *file, void __user *buffer,
+ void __user *buffer,
size_t *length, loff_t *ppos)
{
struct hstate *h = &default_hstate;
table->data = &tmp;
table->maxlen = sizeof(unsigned long);
- proc_doulongvec_minmax(table, write, file, buffer, length, ppos);
+ proc_doulongvec_minmax(table, write, buffer, length, ppos);
if (write) {
spin_lock(&hugetlb_lock);
static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
struct page *page, unsigned long address)
{
+ struct hstate *h = hstate_vma(vma);
struct vm_area_struct *iter_vma;
struct address_space *mapping;
struct prio_tree_iter iter;
* vm_pgoff is in PAGE_SIZE units, hence the different calculation
* from page cache lookup which is in HPAGE_SIZE units.
*/
- address = address & huge_page_mask(hstate_vma(vma));
+ address = address & huge_page_mask(h);
pgoff = ((address - vma->vm_start) >> PAGE_SHIFT)
+ (vma->vm_pgoff >> PAGE_SHIFT);
mapping = (struct address_space *)page_private(page);
*/
if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER))
unmap_hugepage_range(iter_vma,
- address, address + HPAGE_SIZE,
+ address, address + huge_page_size(h),
page);
}
* at the time of fork() could consume its reserves on COW instead
* of the full address range.
*/
- if (!(vma->vm_flags & VM_SHARED) &&
+ if (!(vma->vm_flags & VM_MAYSHARE) &&
is_vma_resv_set(vma, HPAGE_RESV_OWNER) &&
old_page != pagecache_page)
outside_reserve = 1;
return find_lock_page(mapping, idx);
}
+/*
+ * Return whether there is a pagecache page to back given address within VMA.
+ * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page.
+ */
+static bool hugetlbfs_pagecache_present(struct hstate *h,
+ struct vm_area_struct *vma, unsigned long address)
+{
+ struct address_space *mapping;
+ pgoff_t idx;
+ struct page *page;
+
+ mapping = vma->vm_file->f_mapping;
+ idx = vma_hugecache_offset(h, vma, address);
+
+ page = find_get_page(mapping, idx);
+ if (page)
+ put_page(page);
+ return page != NULL;
+}
+
static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long address, pte_t *ptep, int write_access)
+ unsigned long address, pte_t *ptep, unsigned int flags)
{
struct hstate *h = hstate_vma(vma);
int ret = VM_FAULT_SIGBUS;
clear_huge_page(page, address, huge_page_size(h));
__SetPageUptodate(page);
- if (vma->vm_flags & VM_SHARED) {
+ if (vma->vm_flags & VM_MAYSHARE) {
int err;
struct inode *inode = mapping->host;
* any allocations necessary to record that reservation occur outside
* the spinlock.
*/
- if (write_access && !(vma->vm_flags & VM_SHARED))
+ if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED))
if (vma_needs_reservation(h, vma, address) < 0) {
ret = VM_FAULT_OOM;
goto backout_unlocked;
&& (vma->vm_flags & VM_SHARED)));
set_huge_pte_at(mm, address, ptep, new_pte);
- if (write_access && !(vma->vm_flags & VM_SHARED)) {
+ if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) {
/* Optimization, do the COW without a second fault */
ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page);
}
}
int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long address, int write_access)
+ unsigned long address, unsigned int flags)
{
pte_t *ptep;
pte_t entry;
mutex_lock(&hugetlb_instantiation_mutex);
entry = huge_ptep_get(ptep);
if (huge_pte_none(entry)) {
- ret = hugetlb_no_page(mm, vma, address, ptep, write_access);
+ ret = hugetlb_no_page(mm, vma, address, ptep, flags);
goto out_mutex;
}
* page now as it is used to determine if a reservation has been
* consumed.
*/
- if (write_access && !pte_write(entry)) {
+ if ((flags & FAULT_FLAG_WRITE) && !pte_write(entry)) {
if (vma_needs_reservation(h, vma, address) < 0) {
ret = VM_FAULT_OOM;
goto out_mutex;
}
- if (!(vma->vm_flags & VM_SHARED))
+ if (!(vma->vm_flags & VM_MAYSHARE))
pagecache_page = hugetlbfs_pagecache_page(h,
vma, address);
}
goto out_page_table_lock;
- if (write_access) {
+ if (flags & FAULT_FLAG_WRITE) {
if (!pte_write(entry)) {
ret = hugetlb_cow(mm, vma, address, ptep, entry,
pagecache_page);
entry = pte_mkdirty(entry);
}
entry = pte_mkyoung(entry);
- if (huge_ptep_set_access_flags(vma, address, ptep, entry, write_access))
+ if (huge_ptep_set_access_flags(vma, address, ptep, entry,
+ flags & FAULT_FLAG_WRITE))
update_mmu_cache(vma, address, entry);
out_page_table_lock:
return NULL;
}
-static int huge_zeropage_ok(pte_t *ptep, int write, int shared)
-{
- if (!ptep || write || shared)
- return 0;
- else
- return huge_pte_none(huge_ptep_get(ptep));
-}
-
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,
- int write)
+ unsigned int flags)
{
unsigned long pfn_offset;
unsigned long vaddr = *position;
int remainder = *length;
struct hstate *h = hstate_vma(vma);
- int zeropage_ok = 0;
- int shared = vma->vm_flags & VM_SHARED;
spin_lock(&mm->page_table_lock);
while (vaddr < vma->vm_end && remainder) {
pte_t *pte;
+ int absent;
struct page *page;
/*
* Some archs (sparc64, sh*) have multiple pte_ts to
- * each hugepage. We have to make * sure we get the
+ * each hugepage. We have to make sure we get the
* first, for the page indexing below to work.
*/
pte = huge_pte_offset(mm, vaddr & huge_page_mask(h));
- if (huge_zeropage_ok(pte, write, shared))
- zeropage_ok = 1;
+ absent = !pte || huge_pte_none(huge_ptep_get(pte));
- if (!pte ||
- (huge_pte_none(huge_ptep_get(pte)) && !zeropage_ok) ||
- (write && !pte_write(huge_ptep_get(pte)))) {
+ /*
+ * When coredumping, it suits get_dump_page if we just return
+ * an error where there's an empty slot with no huge pagecache
+ * to back it. This way, we avoid allocating a hugepage, and
+ * the sparse dumpfile avoids allocating disk blocks, but its
+ * huge holes still show up with zeroes where they need to be.
+ */
+ if (absent && (flags & FOLL_DUMP) &&
+ !hugetlbfs_pagecache_present(h, vma, vaddr)) {
+ remainder = 0;
+ break;
+ }
+
+ if (absent ||
+ ((flags & FOLL_WRITE) && !pte_write(huge_ptep_get(pte)))) {
int ret;
spin_unlock(&mm->page_table_lock);
- ret = hugetlb_fault(mm, vma, vaddr, write);
+ ret = hugetlb_fault(mm, vma, vaddr,
+ (flags & FOLL_WRITE) ? FAULT_FLAG_WRITE : 0);
spin_lock(&mm->page_table_lock);
if (!(ret & VM_FAULT_ERROR))
continue;
remainder = 0;
- if (!i)
- i = -EFAULT;
break;
}
page = pte_page(huge_ptep_get(pte));
same_page:
if (pages) {
- if (zeropage_ok)
- pages[i] = ZERO_PAGE(0);
- else
- pages[i] = page + pfn_offset;
+ pages[i] = mem_map_offset(page, pfn_offset);
get_page(pages[i]);
}
*length = remainder;
*position = vaddr;
- return i;
+ return i ? i : -EFAULT;
}
void hugetlb_change_protection(struct vm_area_struct *vma,
int hugetlb_reserve_pages(struct inode *inode,
long from, long to,
- struct vm_area_struct *vma)
+ struct vm_area_struct *vma,
+ int acctflag)
{
long ret, chg;
struct hstate *h = hstate_inode(inode);
- if (vma && vma->vm_flags & VM_NORESERVE)
+ /*
+ * Only apply hugepage reservation if asked. At fault time, an
+ * attempt will be made for VM_NORESERVE to allocate a page
+ * and filesystem quota without using reserves
+ */
+ if (acctflag & VM_NORESERVE)
return 0;
/*
* to reserve the full area even if read-only as mprotect() may be
* called to make the mapping read-write. Assume !vma is a shm mapping
*/
- if (!vma || vma->vm_flags & VM_SHARED)
+ if (!vma || vma->vm_flags & VM_MAYSHARE)
chg = region_chg(&inode->i_mapping->private_list, from, to);
else {
struct resv_map *resv_map = resv_map_alloc();
if (chg < 0)
return chg;
+ /* There must be enough filesystem quota for the mapping */
if (hugetlb_get_quota(inode->i_mapping, chg))
return -ENOSPC;
+
+ /*
+ * Check enough hugepages are available for the reservation.
+ * Hand back the quota if there are not
+ */
ret = hugetlb_acct_memory(h, chg);
if (ret < 0) {
hugetlb_put_quota(inode->i_mapping, chg);
return ret;
}
- if (!vma || vma->vm_flags & VM_SHARED)
+
+ /*
+ * Account for the reservations made. Shared mappings record regions
+ * that have reservations as they are shared by multiple VMAs.
+ * When the last VMA disappears, the region map says how much
+ * the reservation was and the page cache tells how much of
+ * the reservation was consumed. Private mappings are per-VMA and
+ * only the consumed reservations are tracked. When the VMA
+ * disappears, the original reservation is the VMA size and the
+ * consumed reservations are stored in the map. Hence, nothing
+ * else has to be done for private mappings here
+ */
+ if (!vma || vma->vm_flags & VM_MAYSHARE)
region_add(&inode->i_mapping->private_list, from, to);
return 0;
}
long chg = region_truncate(&inode->i_mapping->private_list, offset);
spin_lock(&inode->i_lock);
- inode->i_blocks -= blocks_per_huge_page(h);
+ inode->i_blocks -= (blocks_per_huge_page(h) * freed);
spin_unlock(&inode->i_lock);
hugetlb_put_quota(inode->i_mapping, (chg - freed));
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff