#include <linux/rmap.h>
#include <linux/swap.h>
#include <linux/swapops.h>
+#include <linux/page-isolation.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include "internal.h"
const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL;
-static gfp_t htlb_alloc_mask = GFP_HIGHUSER;
unsigned long hugepages_treat_as_movable;
int hugetlb_max_hstate __read_mostly;
static unsigned long __initdata default_hstate_size;
/*
- * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages
+ * Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages,
+ * free_huge_pages, and surplus_huge_pages.
*/
DEFINE_SPINLOCK(hugetlb_lock);
{
struct page *page;
- if (list_empty(&h->hugepage_freelists[nid]))
+ list_for_each_entry(page, &h->hugepage_freelists[nid], lru)
+ if (!is_migrate_isolate_page(page))
+ break;
+ /*
+ * if 'non-isolated free hugepage' not found on the list,
+ * the allocation fails.
+ */
+ if (&h->hugepage_freelists[nid] == &page->lru)
return NULL;
- page = list_entry(h->hugepage_freelists[nid].next, struct page, lru);
list_move(&page->lru, &h->hugepage_activelist);
set_page_refcounted(page);
h->free_huge_pages--;
return page;
}
+/* Movability of hugepages depends on migration support. */
+static inline gfp_t htlb_alloc_mask(struct hstate *h)
+{
+ if (hugepages_treat_as_movable || hugepage_migration_support(h))
+ return GFP_HIGHUSER_MOVABLE;
+ else
+ return GFP_HIGHUSER;
+}
+
static struct page *dequeue_huge_page_vma(struct hstate *h,
struct vm_area_struct *vma,
unsigned long address, int avoid_reserve,
retry_cpuset:
cpuset_mems_cookie = get_mems_allowed();
zonelist = huge_zonelist(vma, address,
- htlb_alloc_mask, &mpol, &nodemask);
+ htlb_alloc_mask(h), &mpol, &nodemask);
for_each_zone_zonelist_nodemask(zone, z, zonelist,
MAX_NR_ZONES - 1, nodemask) {
- if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask)) {
+ if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask(h))) {
page = dequeue_huge_page_node(h, zone_to_nid(zone));
if (page) {
if (avoid_reserve)
if (!vma_has_reserves(vma, chg))
break;
+ SetPagePrivate(page);
h->resv_huge_pages--;
break;
}
int nid = page_to_nid(page);
struct hugepage_subpool *spool =
(struct hugepage_subpool *)page_private(page);
+ bool restore_reserve;
set_page_private(page, 0);
page->mapping = NULL;
BUG_ON(page_count(page));
BUG_ON(page_mapcount(page));
+ restore_reserve = PagePrivate(page);
+ ClearPagePrivate(page);
spin_lock(&hugetlb_lock);
hugetlb_cgroup_uncharge_page(hstate_index(h),
pages_per_huge_page(h), page);
+ if (restore_reserve)
+ h->resv_huge_pages++;
+
if (h->surplus_huge_pages_node[nid] && huge_page_order(h) < MAX_ORDER) {
/* remove the page from active list */
list_del(&page->lru);
/* we rely on prep_new_huge_page to set the destructor */
set_compound_order(page, order);
__SetPageHead(page);
+ __ClearPageReserved(page);
for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) {
__SetPageTail(p);
+ /*
+ * For gigantic hugepages allocated through bootmem at
+ * boot, it's safer to be consistent with the not-gigantic
+ * hugepages and clear the PG_reserved bit from all tail pages
+ * too. Otherwse drivers using get_user_pages() to access tail
+ * pages may get the reference counting wrong if they see
+ * PG_reserved set on a tail page (despite the head page not
+ * having PG_reserved set). Enforcing this consistency between
+ * head and tail pages allows drivers to optimize away a check
+ * on the head page when they need know if put_page() is needed
+ * after get_user_pages().
+ */
+ __ClearPageReserved(p);
set_page_count(p, 0);
p->first_page = page;
}
return NULL;
page = alloc_pages_exact_node(nid,
- htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|
+ htlb_alloc_mask(h)|__GFP_COMP|__GFP_THISNODE|
__GFP_REPEAT|__GFP_NOWARN,
huge_page_order(h));
if (page) {
return ret;
}
+/*
+ * Dissolve a given free hugepage into free buddy pages. This function does
+ * nothing for in-use (including surplus) hugepages.
+ */
+static void dissolve_free_huge_page(struct page *page)
+{
+ spin_lock(&hugetlb_lock);
+ if (PageHuge(page) && !page_count(page)) {
+ struct hstate *h = page_hstate(page);
+ int nid = page_to_nid(page);
+ list_del(&page->lru);
+ h->free_huge_pages--;
+ h->free_huge_pages_node[nid]--;
+ update_and_free_page(h, page);
+ }
+ spin_unlock(&hugetlb_lock);
+}
+
+/*
+ * Dissolve free hugepages in a given pfn range. Used by memory hotplug to
+ * make specified memory blocks removable from the system.
+ * Note that start_pfn should aligned with (minimum) hugepage size.
+ */
+void dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn)
+{
+ unsigned int order = 8 * sizeof(void *);
+ unsigned long pfn;
+ struct hstate *h;
+
+ /* Set scan step to minimum hugepage size */
+ for_each_hstate(h)
+ if (order > huge_page_order(h))
+ order = huge_page_order(h);
+ VM_BUG_ON(!IS_ALIGNED(start_pfn, 1 << order));
+ for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << order)
+ dissolve_free_huge_page(pfn_to_page(pfn));
+}
+
static struct page *alloc_buddy_huge_page(struct hstate *h, int nid)
{
struct page *page;
spin_unlock(&hugetlb_lock);
if (nid == NUMA_NO_NODE)
- page = alloc_pages(htlb_alloc_mask|__GFP_COMP|
+ page = alloc_pages(htlb_alloc_mask(h)|__GFP_COMP|
__GFP_REPEAT|__GFP_NOWARN,
huge_page_order(h));
else
page = alloc_pages_exact_node(nid,
- htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|
+ htlb_alloc_mask(h)|__GFP_COMP|__GFP_THISNODE|
__GFP_REPEAT|__GFP_NOWARN, huge_page_order(h));
if (page && arch_prepare_hugepage(page)) {
return page;
}
+/*
+ * alloc_huge_page()'s wrapper which simply returns the page if allocation
+ * succeeds, otherwise NULL. This function is called from new_vma_page(),
+ * where no ERR_VALUE is expected to be returned.
+ */
+struct page *alloc_huge_page_noerr(struct vm_area_struct *vma,
+ unsigned long addr, int avoid_reserve)
+{
+ struct page *page = alloc_huge_page(vma, addr, avoid_reserve);
+ if (IS_ERR(page))
+ page = NULL;
+ return page;
+}
+
int __weak alloc_bootmem_huge_page(struct hstate *h)
{
struct huge_bootmem_page *m;
#else
page = virt_to_page(m);
#endif
- __ClearPageReserved(page);
WARN_ON(page_count(page) != 1);
prep_compound_huge_page(page, h->order);
+ WARN_ON(PageReserved(page));
prep_new_huge_page(h, page, page_to_nid(page));
/*
* If we had gigantic hugepages allocated at boot time, we need
}
#endif /* CONFIG_NUMA */
-int hugetlb_treat_movable_handler(struct ctl_table *table, int write,
- void __user *buffer,
- size_t *length, loff_t *ppos)
-{
- proc_dointvec(table, write, 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,
void __user *buffer,
size_t *length, loff_t *ppos)
* at the time of fork() could consume its reserves on COW instead
* of the full address range.
*/
- if (!(vma->vm_flags & VM_MAYSHARE) &&
- is_vma_resv_set(vma, HPAGE_RESV_OWNER) &&
+ if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) &&
old_page != pagecache_page)
outside_reserve = 1;
spin_lock(&mm->page_table_lock);
ptep = huge_pte_offset(mm, address & huge_page_mask(h));
if (likely(pte_same(huge_ptep_get(ptep), pte))) {
+ ClearPagePrivate(new_page);
+
/* Break COW */
huge_ptep_clear_flush(vma, address, ptep);
set_huge_pte_at(mm, address, ptep,
}
spin_unlock(&mm->page_table_lock);
mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
- /* Caller expects lock to be held */
- spin_lock(&mm->page_table_lock);
page_cache_release(new_page);
page_cache_release(old_page);
+
+ /* Caller expects lock to be held */
+ spin_lock(&mm->page_table_lock);
return 0;
}
goto retry;
goto out;
}
+ ClearPagePrivate(page);
spin_lock(&inode->i_lock);
inode->i_blocks += blocks_per_huge_page(h);
if (!huge_pte_none(huge_ptep_get(ptep)))
goto backout;
- if (anon_rmap)
+ if (anon_rmap) {
+ ClearPagePrivate(page);
hugepage_add_new_anon_rmap(page, vma, address);
+ }
else
page_dup_rmap(page);
new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE)
return ret;
}
#endif
+
+bool isolate_huge_page(struct page *page, struct list_head *list)
+{
+ VM_BUG_ON(!PageHead(page));
+ if (!get_page_unless_zero(page))
+ return false;
+ spin_lock(&hugetlb_lock);
+ list_move_tail(&page->lru, list);
+ spin_unlock(&hugetlb_lock);
+ return true;
+}
+
+void putback_active_hugepage(struct page *page)
+{
+ VM_BUG_ON(!PageHead(page));
+ spin_lock(&hugetlb_lock);
+ list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist);
+ spin_unlock(&hugetlb_lock);
+ put_page(page);
+}
+
+bool is_hugepage_active(struct page *page)
+{
+ VM_BUG_ON(!PageHuge(page));
+ /*
+ * This function can be called for a tail page because the caller,
+ * scan_movable_pages, scans through a given pfn-range which typically
+ * covers one memory block. In systems using gigantic hugepage (1GB
+ * for x86_64,) a hugepage is larger than a memory block, and we don't
+ * support migrating such large hugepages for now, so return false
+ * when called for tail pages.
+ */
+ if (PageTail(page))
+ return false;
+ /*
+ * Refcount of a hwpoisoned hugepages is 1, but they are not active,
+ * so we should return false for them.
+ */
+ if (unlikely(PageHWPoison(page)))
+ return false;
+ return page_count(page) > 0;
+}
projects / ~andy / linux / blobdiff