pagevec_reinit(pvec);
}
-/*
- * huge_pages_needed tries to determine the number of new huge pages that
- * will be required to fully populate this VMA. This will be equal to
- * the size of the VMA in huge pages minus the number of huge pages
- * (covered by this VMA) that are found in the page cache.
- *
- * Result is in bytes to be compatible with is_hugepage_mem_enough()
- */
-static unsigned long
-huge_pages_needed(struct address_space *mapping, struct vm_area_struct *vma)
-{
- int i;
- struct pagevec pvec;
- unsigned long start = vma->vm_start;
- unsigned long end = vma->vm_end;
- unsigned long hugepages = (end - start) >> HPAGE_SHIFT;
- pgoff_t next = vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT);
- pgoff_t endpg = next + hugepages;
-
- pagevec_init(&pvec, 0);
- while (next < endpg) {
- if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE))
- break;
- for (i = 0; i < pagevec_count(&pvec); i++) {
- struct page *page = pvec.pages[i];
- if (page->index > next)
- next = page->index;
- if (page->index >= endpg)
- break;
- next++;
- hugepages--;
- }
- huge_pagevec_release(&pvec);
- }
- return hugepages << HPAGE_SHIFT;
-}
-
static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
{
struct inode *inode = file->f_dentry->d_inode;
- struct address_space *mapping = inode->i_mapping;
- unsigned long bytes;
+ struct hugetlbfs_inode_info *info = HUGETLBFS_I(inode);
loff_t len, vma_len;
int ret;
if (vma->vm_end - vma->vm_start < HPAGE_SIZE)
return -EINVAL;
- bytes = huge_pages_needed(mapping, vma);
- if (!is_hugepage_mem_enough(bytes))
- return -ENOMEM;
-
vma_len = (loff_t)(vma->vm_end - vma->vm_start);
mutex_lock(&inode->i_mutex);
if (!(vma->vm_flags & VM_WRITE) && len > inode->i_size)
goto out;
+ if (vma->vm_flags & VM_MAYSHARE)
+ if (hugetlb_extend_reservation(info, len >> HPAGE_SHIFT) != 0)
+ goto out;
+
ret = 0;
hugetlb_prefault_arch_hook(vma->vm_mm);
if (inode->i_size < len)
put_page(page);
}
-static void truncate_hugepages(struct address_space *mapping, loff_t lstart)
+static void truncate_hugepages(struct inode *inode, loff_t lstart)
{
+ struct address_space *mapping = &inode->i_data;
const pgoff_t start = lstart >> HPAGE_SHIFT;
struct pagevec pvec;
pgoff_t next;
int i;
+ hugetlb_truncate_reservation(HUGETLBFS_I(inode),
+ lstart >> HPAGE_SHIFT);
+ if (!mapping->nrpages)
+ return;
pagevec_init(&pvec, 0);
next = start;
while (1) {
static void hugetlbfs_delete_inode(struct inode *inode)
{
- if (inode->i_data.nrpages)
- truncate_hugepages(&inode->i_data, 0);
+ truncate_hugepages(inode, 0);
clear_inode(inode);
}
inode->i_state |= I_FREEING;
inodes_stat.nr_inodes--;
spin_unlock(&inode_lock);
- if (inode->i_data.nrpages)
- truncate_hugepages(&inode->i_data, 0);
+ truncate_hugepages(inode, 0);
clear_inode(inode);
destroy_inode(inode);
}
if (!prio_tree_empty(&mapping->i_mmap))
hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff);
spin_unlock(&mapping->i_mmap_lock);
- truncate_hugepages(mapping, offset);
+ truncate_hugepages(inode, offset);
return 0;
}
hugetlbfs_inc_free_inodes(sbinfo);
return NULL;
}
+ p->prereserved_hpages = 0;
return &p->vfs_inode;
}
if (!can_do_hugetlb_shm())
return ERR_PTR(-EPERM);
- if (!is_hugepage_mem_enough(size))
- return ERR_PTR(-ENOMEM);
-
if (!user_shm_lock(size, current->user))
return ERR_PTR(-ENOMEM);
if (!inode)
goto out_file;
+ error = -ENOMEM;
+ if (hugetlb_extend_reservation(HUGETLBFS_I(inode),
+ size >> HPAGE_SHIFT) != 0)
+ goto out_inode;
+
d_instantiate(dentry, inode);
inode->i_size = size;
inode->i_nlink = 0;
file->f_mode = FMODE_WRITE | FMODE_READ;
return file;
+out_inode:
+ iput(inode);
out_file:
put_filp(file);
out_dentry:
int hugetlb_prefault(struct address_space *, struct vm_area_struct *);
int hugetlb_report_meminfo(char *);
int hugetlb_report_node_meminfo(int, char *);
-int is_hugepage_mem_enough(size_t);
unsigned long hugetlb_total_pages(void);
struct page *alloc_huge_page(struct vm_area_struct *, unsigned long);
void free_huge_page(struct page *);
#define copy_hugetlb_page_range(src, dst, vma) ({ BUG(); 0; })
#define hugetlb_prefault(mapping, vma) ({ BUG(); 0; })
#define unmap_hugepage_range(vma, start, end) BUG()
-#define is_hugepage_mem_enough(size) 0
#define hugetlb_report_meminfo(buf) 0
#define hugetlb_report_node_meminfo(n, buf) 0
#define follow_huge_pmd(mm, addr, pmd, write) NULL
struct hugetlbfs_inode_info {
struct shared_policy policy;
+ /* Protected by the (global) hugetlb_lock */
+ unsigned long prereserved_hpages;
struct inode vfs_inode;
};
extern struct file_operations hugetlbfs_file_operations;
extern struct vm_operations_struct hugetlb_vm_ops;
struct file *hugetlb_zero_setup(size_t);
+int hugetlb_extend_reservation(struct hugetlbfs_inode_info *info,
+ unsigned long atleast_hpages);
+void hugetlb_truncate_reservation(struct hugetlbfs_inode_info *info,
+ unsigned long atmost_hpages);
int hugetlb_get_quota(struct address_space *mapping);
void hugetlb_put_quota(struct address_space *mapping);
#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, reserved_huge_pages;
unsigned long max_huge_pages;
static struct list_head hugepage_freelists[MAX_NUMNODES];
static unsigned int nr_huge_pages_node[MAX_NUMNODES];
struct page *alloc_huge_page(struct vm_area_struct *vma, unsigned long addr)
{
+ struct inode *inode = vma->vm_file->f_dentry->d_inode;
struct page *page;
+ int use_reserve = 0;
+ unsigned long idx;
spin_lock(&hugetlb_lock);
- page = dequeue_huge_page(vma, addr);
- if (!page) {
- spin_unlock(&hugetlb_lock);
- return NULL;
+
+ if (vma->vm_flags & VM_MAYSHARE) {
+
+ /* idx = radix tree index, i.e. offset into file in
+ * HPAGE_SIZE units */
+ idx = ((addr - vma->vm_start) >> HPAGE_SHIFT)
+ + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT));
+
+ /* The hugetlbfs specific inode info stores the number
+ * of "guaranteed available" (huge) pages. That is,
+ * the first 'prereserved_hpages' pages of the inode
+ * are either already instantiated, or have been
+ * pre-reserved (by hugetlb_reserve_for_inode()). Here
+ * we're in the process of instantiating the page, so
+ * we use this to determine whether to draw from the
+ * pre-reserved pool or the truly free pool. */
+ if (idx < HUGETLBFS_I(inode)->prereserved_hpages)
+ use_reserve = 1;
+ }
+
+ if (!use_reserve) {
+ if (free_huge_pages <= reserved_huge_pages)
+ goto fail;
+ } else {
+ BUG_ON(reserved_huge_pages == 0);
+ reserved_huge_pages--;
}
+
+ page = dequeue_huge_page(vma, addr);
+ if (!page)
+ goto fail;
+
spin_unlock(&hugetlb_lock);
set_page_refcounted(page);
return page;
+
+ fail:
+ WARN_ON(use_reserve); /* reserved allocations shouldn't fail */
+ spin_unlock(&hugetlb_lock);
+ return NULL;
+}
+
+/* hugetlb_extend_reservation()
+ *
+ * Ensure that at least 'atleast' hugepages are, and will remain,
+ * available to instantiate the first 'atleast' pages of the given
+ * inode. If the inode doesn't already have this many pages reserved
+ * or instantiated, set aside some hugepages in the reserved pool to
+ * satisfy later faults (or fail now if there aren't enough, rather
+ * than getting the SIGBUS later).
+ */
+int hugetlb_extend_reservation(struct hugetlbfs_inode_info *info,
+ unsigned long atleast)
+{
+ struct inode *inode = &info->vfs_inode;
+ unsigned long change_in_reserve = 0;
+ int ret = 0;
+
+ spin_lock(&hugetlb_lock);
+ read_lock_irq(&inode->i_mapping->tree_lock);
+
+ if (info->prereserved_hpages >= atleast)
+ goto out;
+
+ /* Because we always call this on shared mappings, none of the
+ * pages beyond info->prereserved_hpages can have been
+ * instantiated, so we need to reserve all of them now. */
+ change_in_reserve = atleast - info->prereserved_hpages;
+
+ if ((reserved_huge_pages + change_in_reserve) > free_huge_pages) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ reserved_huge_pages += change_in_reserve;
+ info->prereserved_hpages = atleast;
+
+ out:
+ read_unlock_irq(&inode->i_mapping->tree_lock);
+ spin_unlock(&hugetlb_lock);
+
+ return ret;
+}
+
+/* hugetlb_truncate_reservation()
+ *
+ * This returns pages reserved for the given inode to the general free
+ * hugepage pool. If the inode has any pages prereserved, but not
+ * instantiated, beyond offset (atmost << HPAGE_SIZE), then release
+ * them.
+ */
+void hugetlb_truncate_reservation(struct hugetlbfs_inode_info *info,
+ unsigned long atmost)
+{
+ struct inode *inode = &info->vfs_inode;
+ struct address_space *mapping = inode->i_mapping;
+ unsigned long idx;
+ unsigned long change_in_reserve = 0;
+ struct page *page;
+
+ spin_lock(&hugetlb_lock);
+ read_lock_irq(&inode->i_mapping->tree_lock);
+
+ if (info->prereserved_hpages <= atmost)
+ goto out;
+
+ /* Count pages which were reserved, but not instantiated, and
+ * which we can now release. */
+ for (idx = atmost; idx < info->prereserved_hpages; idx++) {
+ page = radix_tree_lookup(&mapping->page_tree, idx);
+ if (!page)
+ /* Pages which are already instantiated can't
+ * be unreserved (and in fact have already
+ * been removed from the reserved pool) */
+ change_in_reserve++;
+ }
+
+ BUG_ON(reserved_huge_pages < change_in_reserve);
+ reserved_huge_pages -= change_in_reserve;
+ info->prereserved_hpages = atmost;
+
+ out:
+ read_unlock_irq(&inode->i_mapping->tree_lock);
+ spin_unlock(&hugetlb_lock);
}
static int __init hugetlb_init(void)
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,
+ reserved_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)
{
projects / users / willy / pagecache.git / commitdiff