const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL;
static unsigned long nr_huge_pages, free_huge_pages, resv_huge_pages;
+static unsigned long surplus_huge_pages;
+static unsigned long nr_overcommit_huge_pages;
unsigned long max_huge_pages;
+unsigned long sysctl_overcommit_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];
+static unsigned int surplus_huge_pages_node[MAX_NUMNODES];
+static gfp_t htlb_alloc_mask = GFP_HIGHUSER;
+unsigned long hugepages_treat_as_movable;
+static int hugetlb_next_nid;
+
/*
* Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages
*/
might_sleep();
for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); i++) {
cond_resched();
- clear_user_highpage(page + i, addr);
+ clear_user_highpage(page + i, addr + i * PAGE_SIZE);
}
}
static void copy_huge_page(struct page *dst, struct page *src,
- unsigned long addr)
+ unsigned long addr, struct vm_area_struct *vma)
{
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);
+ copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma);
}
}
free_huge_pages_node[nid]++;
}
-static struct page *dequeue_huge_page(struct vm_area_struct *vma,
- unsigned long address)
+static struct page *dequeue_huge_page(void)
{
- int nid = numa_node_id();
+ int nid;
struct page *page = NULL;
- struct zonelist *zonelist = huge_zonelist(vma, address);
- struct zone **z;
- for (z = zonelist->zones; *z; z++) {
- nid = zone_to_nid(*z);
- if (cpuset_zone_allowed(*z, GFP_HIGHUSER) &&
- !list_empty(&hugepage_freelists[nid]))
+ for (nid = 0; nid < MAX_NUMNODES; ++nid) {
+ if (!list_empty(&hugepage_freelists[nid])) {
+ page = list_entry(hugepage_freelists[nid].next,
+ struct page, lru);
+ list_del(&page->lru);
+ free_huge_pages--;
+ free_huge_pages_node[nid]--;
break;
+ }
}
+ return page;
+}
- if (*z) {
- page = list_entry(hugepage_freelists[nid].next,
- struct page, lru);
- list_del(&page->lru);
- free_huge_pages--;
- free_huge_pages_node[nid]--;
+static struct page *dequeue_huge_page_vma(struct vm_area_struct *vma,
+ unsigned long address)
+{
+ int nid;
+ struct page *page = NULL;
+ struct mempolicy *mpol;
+ nodemask_t *nodemask;
+ struct zonelist *zonelist = huge_zonelist(vma, address,
+ htlb_alloc_mask, &mpol, &nodemask);
+ struct zone *zone;
+ struct zoneref *z;
+
+ for_each_zone_zonelist_nodemask(zone, z, zonelist,
+ MAX_NR_ZONES - 1, nodemask) {
+ nid = zone_to_nid(zone);
+ if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) &&
+ !list_empty(&hugepage_freelists[nid])) {
+ page = list_entry(hugepage_freelists[nid].next,
+ struct page, lru);
+ list_del(&page->lru);
+ free_huge_pages--;
+ free_huge_pages_node[nid]--;
+ if (vma && vma->vm_flags & VM_MAYSHARE)
+ resv_huge_pages--;
+ break;
+ }
}
+ mpol_cond_put(mpol);
return page;
}
+static void update_and_free_page(struct page *page)
+{
+ int i;
+ nr_huge_pages--;
+ 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_compound_page_dtor(page, NULL);
+ set_page_refcounted(page);
+ arch_release_hugepage(page);
+ __free_pages(page, HUGETLB_PAGE_ORDER);
+}
+
static void free_huge_page(struct page *page)
{
- BUG_ON(page_count(page));
+ int nid = page_to_nid(page);
+ struct address_space *mapping;
+ mapping = (struct address_space *) page_private(page);
+ set_page_private(page, 0);
+ BUG_ON(page_count(page));
INIT_LIST_HEAD(&page->lru);
spin_lock(&hugetlb_lock);
- enqueue_huge_page(page);
+ if (surplus_huge_pages_node[nid]) {
+ update_and_free_page(page);
+ surplus_huge_pages--;
+ surplus_huge_pages_node[nid]--;
+ } else {
+ enqueue_huge_page(page);
+ }
spin_unlock(&hugetlb_lock);
+ if (mapping)
+ hugetlb_put_quota(mapping, 1);
}
-static int alloc_fresh_huge_page(void)
+/*
+ * 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(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 && !surplus_huge_pages_node[nid])
+ continue;
+ /* Surplus cannot exceed the total number of pages */
+ if (delta > 0 && surplus_huge_pages_node[nid] >=
+ nr_huge_pages_node[nid])
+ continue;
+
+ surplus_huge_pages += delta;
+ surplus_huge_pages_node[nid] += delta;
+ ret = 1;
+ break;
+ } while (nid != prev_nid);
+
+ prev_nid = nid;
+ return ret;
+}
+
+static struct page *alloc_fresh_huge_page_node(int nid)
{
- static int nid = 0;
struct page *page;
- page = alloc_pages_node(nid, GFP_HIGHUSER|__GFP_COMP|__GFP_NOWARN,
- HUGETLB_PAGE_ORDER);
- nid = next_node(nid, node_online_map);
- if (nid == MAX_NUMNODES)
- nid = first_node(node_online_map);
+
+ page = alloc_pages_node(nid,
+ htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|
+ __GFP_REPEAT|__GFP_NOWARN,
+ HUGETLB_PAGE_ORDER);
if (page) {
- page[1].lru.next = (void *)free_huge_page; /* dtor */
+ if (arch_prepare_hugepage(page)) {
+ __free_pages(page, HUGETLB_PAGE_ORDER);
+ return NULL;
+ }
+ set_compound_page_dtor(page, free_huge_page);
spin_lock(&hugetlb_lock);
nr_huge_pages++;
- nr_huge_pages_node[page_to_nid(page)]++;
+ nr_huge_pages_node[nid]++;
spin_unlock(&hugetlb_lock);
put_page(page); /* free it into the hugepage allocator */
- return 1;
}
- return 0;
+
+ return page;
}
-static struct page *alloc_huge_page(struct vm_area_struct *vma,
- unsigned long addr)
+static int alloc_fresh_huge_page(void)
{
struct page *page;
+ int start_nid;
+ int next_nid;
+ int ret = 0;
+
+ start_nid = hugetlb_next_nid;
+
+ do {
+ page = alloc_fresh_huge_page_node(hugetlb_next_nid);
+ if (page)
+ ret = 1;
+ /*
+ * Use a helper variable to find the next node and then
+ * copy it back to hugetlb_next_nid afterwards:
+ * otherwise there's a window in which a racer might
+ * pass invalid nid MAX_NUMNODES to alloc_pages_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.
+ */
+ next_nid = next_node(hugetlb_next_nid, node_online_map);
+ if (next_nid == MAX_NUMNODES)
+ next_nid = first_node(node_online_map);
+ hugetlb_next_nid = next_nid;
+ } while (!page && hugetlb_next_nid != start_nid);
+
+ if (ret)
+ count_vm_event(HTLB_BUDDY_PGALLOC);
+ else
+ count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
+ return ret;
+}
+
+static struct page *alloc_buddy_huge_page(struct vm_area_struct *vma,
+ unsigned long address)
+{
+ struct page *page;
+ unsigned int nid;
+
+ /*
+ * Assume we will successfully allocate the surplus page to
+ * prevent racing processes from causing the surplus to exceed
+ * overcommit
+ *
+ * This however introduces a different race, where a process B
+ * tries to grow the static hugepage pool while alloc_pages() is
+ * called by process A. B will only examine the per-node
+ * counters in determining if surplus huge pages can be
+ * converted to normal huge pages in adjust_pool_surplus(). A
+ * won't be able to increment the per-node counter, until the
+ * lock is dropped by B, but B doesn't drop hugetlb_lock until
+ * no more huge pages can be converted from surplus to normal
+ * state (and doesn't try to convert again). Thus, we have a
+ * case where a surplus huge page exists, the pool is grown, and
+ * the surplus huge page still exists after, even though it
+ * should just have been converted to a normal huge page. This
+ * does not leak memory, though, as the hugepage will be freed
+ * once it is out of use. It also does not allow the counters to
+ * go out of whack in adjust_pool_surplus() as we don't modify
+ * the node values until we've gotten the hugepage and only the
+ * per-node value is checked there.
+ */
spin_lock(&hugetlb_lock);
- if (vma->vm_flags & VM_MAYSHARE)
- resv_huge_pages--;
- else if (free_huge_pages <= resv_huge_pages)
- goto fail;
+ if (surplus_huge_pages >= nr_overcommit_huge_pages) {
+ spin_unlock(&hugetlb_lock);
+ return NULL;
+ } else {
+ nr_huge_pages++;
+ surplus_huge_pages++;
+ }
+ spin_unlock(&hugetlb_lock);
- page = dequeue_huge_page(vma, addr);
- if (!page)
- goto fail;
+ page = alloc_pages(htlb_alloc_mask|__GFP_COMP|
+ __GFP_REPEAT|__GFP_NOWARN,
+ HUGETLB_PAGE_ORDER);
+ spin_lock(&hugetlb_lock);
+ if (page) {
+ /*
+ * This page is now managed by the hugetlb allocator and has
+ * no users -- drop the buddy allocator's reference.
+ */
+ put_page_testzero(page);
+ VM_BUG_ON(page_count(page));
+ nid = page_to_nid(page);
+ set_compound_page_dtor(page, free_huge_page);
+ /*
+ * We incremented the global counters already
+ */
+ nr_huge_pages_node[nid]++;
+ surplus_huge_pages_node[nid]++;
+ __count_vm_event(HTLB_BUDDY_PGALLOC);
+ } else {
+ nr_huge_pages--;
+ surplus_huge_pages--;
+ __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
+ }
spin_unlock(&hugetlb_lock);
- set_page_refcounted(page);
+
return page;
+}
+
+/*
+ * Increase the hugetlb pool such that it can accomodate a reservation
+ * of size 'delta'.
+ */
+static int gather_surplus_pages(int delta)
+{
+ struct list_head surplus_list;
+ struct page *page, *tmp;
+ int ret, i;
+ int needed, allocated;
+
+ needed = (resv_huge_pages + delta) - free_huge_pages;
+ if (needed <= 0) {
+ resv_huge_pages += delta;
+ return 0;
+ }
+
+ allocated = 0;
+ INIT_LIST_HEAD(&surplus_list);
+
+ ret = -ENOMEM;
+retry:
+ spin_unlock(&hugetlb_lock);
+ for (i = 0; i < needed; i++) {
+ page = alloc_buddy_huge_page(NULL, 0);
+ if (!page) {
+ /*
+ * We were not able to allocate enough pages to
+ * satisfy the entire reservation so we free what
+ * we've allocated so far.
+ */
+ spin_lock(&hugetlb_lock);
+ needed = 0;
+ goto free;
+ }
+
+ list_add(&page->lru, &surplus_list);
+ }
+ allocated += needed;
+
+ /*
+ * After retaking hugetlb_lock, we need to recalculate 'needed'
+ * because either resv_huge_pages or free_huge_pages may have changed.
+ */
+ spin_lock(&hugetlb_lock);
+ needed = (resv_huge_pages + delta) - (free_huge_pages + allocated);
+ if (needed > 0)
+ goto retry;
+
+ /*
+ * The surplus_list now contains _at_least_ the number of extra pages
+ * needed to accomodate the reservation. Add the appropriate number
+ * of pages to the hugetlb pool and free the extras back to the buddy
+ * allocator. Commit the entire reservation here to prevent another
+ * process from stealing the pages as they are added to the pool but
+ * before they are reserved.
+ */
+ needed += allocated;
+ resv_huge_pages += delta;
+ ret = 0;
+free:
+ /* Free the needed pages to the hugetlb pool */
+ list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
+ if ((--needed) < 0)
+ break;
+ list_del(&page->lru);
+ enqueue_huge_page(page);
+ }
+
+ /* Free unnecessary surplus pages to the buddy allocator */
+ if (!list_empty(&surplus_list)) {
+ spin_unlock(&hugetlb_lock);
+ list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
+ list_del(&page->lru);
+ /*
+ * The page has a reference count of zero already, so
+ * call free_huge_page directly instead of using
+ * put_page. This must be done with hugetlb_lock
+ * unlocked which is safe because free_huge_page takes
+ * hugetlb_lock before deciding how to free the page.
+ */
+ free_huge_page(page);
+ }
+ spin_lock(&hugetlb_lock);
+ }
+
+ return ret;
+}
+
+/*
+ * 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.
+ */
+static void return_unused_surplus_pages(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 */
+ resv_huge_pages -= unused_resv_pages;
+
+ nr_pages = min(unused_resv_pages, 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);
-fail:
+ if (!surplus_huge_pages_node[nid])
+ continue;
+
+ if (!list_empty(&hugepage_freelists[nid])) {
+ page = list_entry(hugepage_freelists[nid].next,
+ struct page, lru);
+ list_del(&page->lru);
+ update_and_free_page(page);
+ free_huge_pages--;
+ free_huge_pages_node[nid]--;
+ surplus_huge_pages--;
+ surplus_huge_pages_node[nid]--;
+ nr_pages--;
+ remaining_iterations = num_online_nodes();
+ }
+ }
+}
+
+
+static struct page *alloc_huge_page_shared(struct vm_area_struct *vma,
+ unsigned long addr)
+{
+ struct page *page;
+
+ spin_lock(&hugetlb_lock);
+ page = dequeue_huge_page_vma(vma, addr);
spin_unlock(&hugetlb_lock);
- return NULL;
+ return page ? page : ERR_PTR(-VM_FAULT_OOM);
+}
+
+static struct page *alloc_huge_page_private(struct vm_area_struct *vma,
+ unsigned long addr)
+{
+ struct page *page = NULL;
+
+ if (hugetlb_get_quota(vma->vm_file->f_mapping, 1))
+ return ERR_PTR(-VM_FAULT_SIGBUS);
+
+ spin_lock(&hugetlb_lock);
+ if (free_huge_pages > resv_huge_pages)
+ page = dequeue_huge_page_vma(vma, addr);
+ spin_unlock(&hugetlb_lock);
+ if (!page) {
+ page = alloc_buddy_huge_page(vma, addr);
+ if (!page) {
+ hugetlb_put_quota(vma->vm_file->f_mapping, 1);
+ return ERR_PTR(-VM_FAULT_OOM);
+ }
+ }
+ return page;
+}
+
+static struct page *alloc_huge_page(struct vm_area_struct *vma,
+ unsigned long addr)
+{
+ struct page *page;
+ struct address_space *mapping = vma->vm_file->f_mapping;
+
+ if (vma->vm_flags & VM_MAYSHARE)
+ page = alloc_huge_page_shared(vma, addr);
+ else
+ page = alloc_huge_page_private(vma, addr);
+
+ if (!IS_ERR(page)) {
+ set_page_refcounted(page);
+ set_page_private(page, (unsigned long) mapping);
+ }
+ return page;
}
static int __init hugetlb_init(void)
for (i = 0; i < MAX_NUMNODES; ++i)
INIT_LIST_HEAD(&hugepage_freelists[i]);
+ hugetlb_next_nid = first_node(node_online_map);
+
for (i = 0; i < max_huge_pages; ++i) {
if (!alloc_fresh_huge_page())
break;
}
__setup("hugepages=", hugetlb_setup);
-#ifdef CONFIG_SYSCTL
-static void update_and_free_page(struct page *page)
+static unsigned int cpuset_mems_nr(unsigned int *array)
{
- int i;
- nr_huge_pages--;
- 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);
- }
- page[1].lru.next = NULL;
- set_page_refcounted(page);
- __free_pages(page, HUGETLB_PAGE_ORDER);
+ int node;
+ unsigned int nr = 0;
+
+ for_each_node_mask(node, cpuset_current_mems_allowed)
+ nr += array[node];
+
+ return nr;
}
+#ifdef CONFIG_SYSCTL
#ifdef CONFIG_HIGHMEM
static void try_to_free_low(unsigned long count)
{
for (i = 0; i < MAX_NUMNODES; ++i) {
struct page *page, *next;
list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) {
+ if (count >= nr_huge_pages)
+ return;
if (PageHighMem(page))
continue;
list_del(&page->lru);
update_and_free_page(page);
free_huge_pages--;
free_huge_pages_node[page_to_nid(page)]--;
- if (count >= nr_huge_pages)
- return;
}
}
}
}
#endif
+#define persistent_huge_pages (nr_huge_pages - surplus_huge_pages)
static unsigned long set_max_huge_pages(unsigned long count)
{
- while (count > nr_huge_pages) {
- if (!alloc_fresh_huge_page())
- return nr_huge_pages;
- }
- if (count >= nr_huge_pages)
- return nr_huge_pages;
+ unsigned long min_count, ret;
+ /*
+ * Increase the pool size
+ * First take pages out of surplus state. Then make up the
+ * remaining difference by allocating fresh huge pages.
+ *
+ * We might race with alloc_buddy_huge_page() here and be unable
+ * to convert a surplus huge page to a normal huge page. That is
+ * not critical, though, it just means the overall size of the
+ * pool might be one hugepage larger than it needs to be, but
+ * within all the constraints specified by the sysctls.
+ */
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);
+ while (surplus_huge_pages && count > persistent_huge_pages) {
+ if (!adjust_pool_surplus(-1))
+ break;
+ }
+
+ while (count > persistent_huge_pages) {
+ int ret;
+ /*
+ * If this allocation races such that we no longer need the
+ * page, free_huge_page will handle it by freeing the page
+ * and reducing the surplus.
+ */
+ spin_unlock(&hugetlb_lock);
+ ret = alloc_fresh_huge_page();
+ spin_lock(&hugetlb_lock);
+ if (!ret)
+ goto out;
+
+ }
+
+ /*
+ * Decrease the pool size
+ * First return free pages to the buddy allocator (being careful
+ * to keep enough around to satisfy reservations). Then place
+ * pages into surplus state as needed so the pool will shrink
+ * to the desired size as pages become free.
+ *
+ * By placing pages into the surplus state independent of the
+ * overcommit value, we are allowing the surplus pool size to
+ * exceed overcommit. There are few sane options here. Since
+ * alloc_buddy_huge_page() is checking the global counter,
+ * though, we'll note that we're not allowed to exceed surplus
+ * and won't grow the pool anywhere else. Not until one of the
+ * sysctls are changed, or the surplus pages go out of use.
+ */
+ min_count = resv_huge_pages + nr_huge_pages - free_huge_pages;
+ min_count = max(count, min_count);
+ try_to_free_low(min_count);
+ while (min_count < persistent_huge_pages) {
+ struct page *page = dequeue_huge_page();
if (!page)
break;
update_and_free_page(page);
}
+ while (count < persistent_huge_pages) {
+ if (!adjust_pool_surplus(1))
+ break;
+ }
+out:
+ ret = persistent_huge_pages;
spin_unlock(&hugetlb_lock);
- return nr_huge_pages;
+ return ret;
}
int hugetlb_sysctl_handler(struct ctl_table *table, int write,
max_huge_pages = set_max_huge_pages(max_huge_pages);
return 0;
}
+
+int hugetlb_treat_movable_handler(struct ctl_table *table, int write,
+ struct file *file, void __user *buffer,
+ size_t *length, loff_t *ppos)
+{
+ proc_dointvec(table, write, file, buffer, length, ppos);
+ if (hugepages_treat_as_movable)
+ htlb_alloc_mask = GFP_HIGHUSER_MOVABLE;
+ else
+ htlb_alloc_mask = GFP_HIGHUSER;
+ return 0;
+}
+
+int hugetlb_overcommit_handler(struct ctl_table *table, int write,
+ struct file *file, void __user *buffer,
+ size_t *length, loff_t *ppos)
+{
+ proc_doulongvec_minmax(table, write, file, buffer, length, ppos);
+ spin_lock(&hugetlb_lock);
+ nr_overcommit_huge_pages = sysctl_overcommit_huge_pages;
+ spin_unlock(&hugetlb_lock);
+ return 0;
+}
+
#endif /* CONFIG_SYSCTL */
int hugetlb_report_meminfo(char *buf)
"HugePages_Total: %5lu\n"
"HugePages_Free: %5lu\n"
"HugePages_Rsvd: %5lu\n"
+ "HugePages_Surp: %5lu\n"
"Hugepagesize: %5lu kB\n",
nr_huge_pages,
free_huge_pages,
resv_huge_pages,
+ surplus_huge_pages,
HPAGE_SIZE/1024);
}
{
return sprintf(buf,
"Node %d HugePages_Total: %5u\n"
- "Node %d HugePages_Free: %5u\n",
+ "Node %d HugePages_Free: %5u\n"
+ "Node %d HugePages_Surp: %5u\n",
nid, nr_huge_pages_node[nid],
- nid, free_huge_pages_node[nid]);
+ nid, free_huge_pages_node[nid],
+ nid, surplus_huge_pages_node[nid]);
}
/* Return the number pages of memory we physically have, in PAGE_SIZE units. */
* hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get
* this far.
*/
-static struct page *hugetlb_nopage(struct vm_area_struct *vma,
- unsigned long address, int *unused)
+static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
BUG();
- return NULL;
+ return 0;
}
struct vm_operations_struct hugetlb_vm_ops = {
- .nopage = hugetlb_nopage,
+ .fault = hugetlb_vm_op_fault,
};
static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page,
entry =
pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot)));
} else {
- entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot));
+ entry = huge_pte_wrprotect(mk_pte(page, vma->vm_page_prot));
}
entry = pte_mkyoung(entry);
entry = pte_mkhuge(entry);
{
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);
+ entry = pte_mkwrite(pte_mkdirty(huge_ptep_get(ptep)));
+ if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) {
+ update_mmu_cache(vma, address, entry);
+ }
}
dst_pte = huge_pte_alloc(dst, addr);
if (!dst_pte)
goto nomem;
+
+ /* If the pagetables are shared don't copy or take references */
+ if (dst_pte == src_pte)
+ continue;
+
spin_lock(&dst->page_table_lock);
spin_lock(&src->page_table_lock);
- if (!pte_none(*src_pte)) {
+ if (!huge_pte_none(huge_ptep_get(src_pte))) {
if (cow)
- ptep_set_wrprotect(src, addr, src_pte);
- entry = *src_pte;
+ huge_ptep_set_wrprotect(src, addr, src_pte);
+ entry = huge_ptep_get(src_pte);
ptepage = pte_page(entry);
get_page(ptepage);
- add_mm_counter(dst, file_rss, HPAGE_SIZE / PAGE_SIZE);
set_huge_pte_at(dst, addr, dst_pte, entry);
}
spin_unlock(&src->page_table_lock);
return -ENOMEM;
}
-void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
- unsigned long end)
+void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
+ unsigned long end)
{
struct mm_struct *mm = vma->vm_mm;
unsigned long address;
pte_t *ptep;
pte_t pte;
struct page *page;
+ struct page *tmp;
+ /*
+ * A page gathering list, protected by per file i_mmap_lock. The
+ * lock is used to avoid list corruption from multiple unmapping
+ * of the same page since we are using page->lru.
+ */
+ LIST_HEAD(page_list);
WARN_ON(!is_vm_hugetlb_page(vma));
BUG_ON(start & ~HPAGE_MASK);
BUG_ON(end & ~HPAGE_MASK);
spin_lock(&mm->page_table_lock);
-
- /* Update high watermark before we lower rss */
- update_hiwater_rss(mm);
-
for (address = start; address < end; address += HPAGE_SIZE) {
ptep = huge_pte_offset(mm, address);
if (!ptep)
continue;
+ if (huge_pmd_unshare(mm, &address, ptep))
+ continue;
+
pte = huge_ptep_get_and_clear(mm, address, ptep);
- if (pte_none(pte))
+ if (huge_pte_none(pte))
continue;
page = pte_page(pte);
- put_page(page);
- add_mm_counter(mm, file_rss, (int) -(HPAGE_SIZE / PAGE_SIZE));
+ if (pte_dirty(pte))
+ set_page_dirty(page);
+ list_add(&page->lru, &page_list);
}
-
spin_unlock(&mm->page_table_lock);
flush_tlb_range(vma, start, end);
+ list_for_each_entry_safe(page, tmp, &page_list, lru) {
+ list_del(&page->lru);
+ put_page(page);
+ }
+}
+
+void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
+ unsigned long end)
+{
+ /*
+ * It is undesirable to test vma->vm_file as it should be non-null
+ * for valid hugetlb area. However, vm_file will be NULL in the error
+ * cleanup path of do_mmap_pgoff. When hugetlbfs ->mmap method fails,
+ * do_mmap_pgoff() nullifies vma->vm_file before calling this function
+ * to clean up. Since no pte has actually been setup, it is safe to
+ * do nothing in this case.
+ */
+ if (vma->vm_file) {
+ spin_lock(&vma->vm_file->f_mapping->i_mmap_lock);
+ __unmap_hugepage_range(vma, start, end);
+ spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock);
+ }
}
static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
avoidcopy = (page_count(old_page) == 1);
if (avoidcopy) {
set_huge_ptep_writable(vma, address, ptep);
- return VM_FAULT_MINOR;
+ return 0;
}
page_cache_get(old_page);
new_page = alloc_huge_page(vma, address);
- if (!new_page) {
+ if (IS_ERR(new_page)) {
page_cache_release(old_page);
- return VM_FAULT_OOM;
+ return -PTR_ERR(new_page);
}
spin_unlock(&mm->page_table_lock);
- copy_huge_page(new_page, old_page, address);
+ copy_huge_page(new_page, old_page, address, vma);
+ __SetPageUptodate(new_page);
spin_lock(&mm->page_table_lock);
ptep = huge_pte_offset(mm, address & HPAGE_MASK);
- if (likely(pte_same(*ptep, pte))) {
+ if (likely(pte_same(huge_ptep_get(ptep), pte))) {
/* Break COW */
+ huge_ptep_clear_flush(vma, address, ptep);
set_huge_pte_at(mm, address, ptep,
make_huge_pte(vma, new_page, 1));
/* Make the old page be freed below */
}
page_cache_release(new_page);
page_cache_release(old_page);
- return VM_FAULT_MINOR;
+ return 0;
}
-int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
+static 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;
retry:
page = find_lock_page(mapping, idx);
if (!page) {
- if (hugetlb_get_quota(mapping))
+ size = i_size_read(mapping->host) >> HPAGE_SHIFT;
+ if (idx >= size)
goto out;
page = alloc_huge_page(vma, address);
- if (!page) {
- hugetlb_put_quota(mapping);
- ret = VM_FAULT_OOM;
+ if (IS_ERR(page)) {
+ ret = -PTR_ERR(page);
goto out;
}
clear_huge_page(page, address);
+ __SetPageUptodate(page);
if (vma->vm_flags & VM_SHARED) {
int err;
+ struct inode *inode = mapping->host;
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;
}
+
+ spin_lock(&inode->i_lock);
+ inode->i_blocks += BLOCKS_PER_HUGEPAGE;
+ spin_unlock(&inode->i_lock);
} else
lock_page(page);
}
if (idx >= size)
goto backout;
- ret = VM_FAULT_MINOR;
- if (!pte_none(*ptep))
+ ret = 0;
+ if (!huge_pte_none(huge_ptep_get(ptep)))
goto backout;
- add_mm_counter(mm, file_rss, HPAGE_SIZE / PAGE_SIZE);
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);
backout:
spin_unlock(&mm->page_table_lock);
- hugetlb_put_quota(mapping);
unlock_page(page);
put_page(page);
goto out;
* the same page in the page cache.
*/
mutex_lock(&hugetlb_instantiation_mutex);
- entry = *ptep;
- if (pte_none(entry)) {
+ entry = huge_ptep_get(ptep);
+ if (huge_pte_none(entry)) {
ret = hugetlb_no_page(mm, vma, address, ptep, write_access);
mutex_unlock(&hugetlb_instantiation_mutex);
return ret;
}
- ret = VM_FAULT_MINOR;
+ ret = 0;
spin_lock(&mm->page_table_lock);
/* Check for a racing update before calling hugetlb_cow */
- if (likely(pte_same(entry, *ptep)))
+ if (likely(pte_same(entry, huge_ptep_get(ptep))))
if (write_access && !pte_write(entry))
ret = hugetlb_cow(mm, vma, address, ptep, entry);
spin_unlock(&mm->page_table_lock);
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)
+ unsigned long *position, int *length, int i,
+ int write)
{
unsigned long pfn_offset;
unsigned long vaddr = *position;
*/
pte = huge_pte_offset(mm, vaddr & HPAGE_MASK);
- if (!pte || pte_none(*pte)) {
+ if (!pte || huge_pte_none(huge_ptep_get(pte)) ||
+ (write && !pte_write(huge_ptep_get(pte)))) {
int ret;
spin_unlock(&mm->page_table_lock);
- ret = hugetlb_fault(mm, vma, vaddr, 0);
+ ret = hugetlb_fault(mm, vma, vaddr, write);
spin_lock(&mm->page_table_lock);
- if (ret == VM_FAULT_MINOR)
+ if (!(ret & VM_FAULT_ERROR))
continue;
remainder = 0;
}
pfn_offset = (vaddr & ~HPAGE_MASK) >> PAGE_SHIFT;
- page = pte_page(*pte);
+ page = pte_page(huge_ptep_get(pte));
same_page:
if (pages) {
get_page(page);
BUG_ON(address >= end);
flush_cache_range(vma, address, end);
+ spin_lock(&vma->vm_file->f_mapping->i_mmap_lock);
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)) {
+ if (huge_pmd_unshare(mm, &address, ptep))
+ continue;
+ if (!huge_pte_none(huge_ptep_get(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);
+ spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock);
flush_tlb_range(vma, start, end);
}
/* 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. */
+ * size such that we can guarantee to record the reservation. */
if (&rg->link == head || t < rg->from) {
nrg = kmalloc(sizeof(*nrg), GFP_KERNEL);
- if (nrg == 0)
+ if (!nrg)
return -ENOMEM;
nrg->from = f;
nrg->to = f;
int ret = -ENOMEM;
spin_lock(&hugetlb_lock);
- if ((delta + resv_huge_pages) <= free_huge_pages) {
- resv_huge_pages += delta;
- ret = 0;
+ /*
+ * When cpuset is configured, it breaks the strict hugetlb page
+ * reservation as the accounting is done on a global variable. Such
+ * reservation is completely rubbish in the presence of cpuset because
+ * the reservation is not checked against page availability for the
+ * current cpuset. Application can still potentially OOM'ed by kernel
+ * with lack of free htlb page in cpuset that the task is in.
+ * Attempt to enforce strict accounting with cpuset is almost
+ * impossible (or too ugly) because cpuset is too fluid that
+ * task or memory node can be dynamically moved between cpusets.
+ *
+ * The change of semantics for shared hugetlb mapping with cpuset is
+ * undesirable. However, in order to preserve some of the semantics,
+ * we fall back to check against current free page availability as
+ * a best attempt and hopefully to minimize the impact of changing
+ * semantics that cpuset has.
+ */
+ if (delta > 0) {
+ if (gather_surplus_pages(delta) < 0)
+ goto out;
+
+ if (delta > cpuset_mems_nr(free_huge_pages_node)) {
+ return_unused_surplus_pages(delta);
+ goto out;
+ }
}
+
+ ret = 0;
+ if (delta < 0)
+ return_unused_surplus_pages((unsigned long) -delta);
+
+out:
spin_unlock(&hugetlb_lock);
return ret;
}
chg = region_chg(&inode->i_mapping->private_list, from, to);
if (chg < 0)
return chg;
+
+ if (hugetlb_get_quota(inode->i_mapping, chg))
+ return -ENOSPC;
ret = hugetlb_acct_memory(chg);
- if (ret < 0)
+ if (ret < 0) {
+ hugetlb_put_quota(inode->i_mapping, chg);
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);
+
+ spin_lock(&inode->i_lock);
+ inode->i_blocks -= BLOCKS_PER_HUGEPAGE * freed;
+ spin_unlock(&inode->i_lock);
+
+ hugetlb_put_quota(inode->i_mapping, (chg - freed));
+ hugetlb_acct_memory(-(chg - freed));
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff