#include <linux/init.h>
#include <linux/module.h>
#include <linux/mm.h>
+#include <linux/seq_file.h>
#include <linux/sysctl.h>
#include <linux/highmem.h>
+#include <linux/mmu_notifier.h>
#include <linux/nodemask.h>
#include <linux/pagemap.h>
#include <linux/mempolicy.h>
#include <linux/cpuset.h>
#include <linux/mutex.h>
+#include <linux/bootmem.h>
+#include <linux/sysfs.h>
#include <asm/page.h>
#include <asm/pgtable.h>
+#include <asm/io.h>
#include <linux/hugetlb.h>
#include "internal.h"
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;
+
+static int max_hstate;
+unsigned int default_hstate_idx;
+struct hstate hstates[HUGE_MAX_HSTATE];
+
+__initdata LIST_HEAD(huge_boot_pages);
+
+/* for command line parsing */
+static struct hstate * __initdata parsed_hstate;
+static unsigned long __initdata default_hstate_max_huge_pages;
+static unsigned long __initdata default_hstate_size;
+
+#define for_each_hstate(h) \
+ for ((h) = hstates; (h) < &hstates[max_hstate]; (h)++)
/*
* Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages
*/
static DEFINE_SPINLOCK(hugetlb_lock);
-static void clear_huge_page(struct page *page, unsigned long addr)
+/*
+ * Region tracking -- allows tracking of reservations and instantiated pages
+ * across the pages in a mapping.
+ *
+ * The region data structures are protected by a combination of the mmap_sem
+ * and the hugetlb_instantion_mutex. To access or modify a region the caller
+ * must either hold the mmap_sem for write, or the mmap_sem for read and
+ * the hugetlb_instantiation mutex:
+ *
+ * down_write(&mm->mmap_sem);
+ * or
+ * down_read(&mm->mmap_sem);
+ * mutex_lock(&hugetlb_instantiation_mutex);
+ */
+struct file_region {
+ struct list_head link;
+ long from;
+ long to;
+};
+
+static long region_add(struct list_head *head, long f, long t)
+{
+ struct file_region *rg, *nrg, *trg;
+
+ /* Locate the region we are either in or before. */
+ list_for_each_entry(rg, head, link)
+ if (f <= rg->to)
+ break;
+
+ /* Round our left edge to the current segment if it encloses us. */
+ if (f > rg->from)
+ f = rg->from;
+
+ /* Check for and consume any regions we now overlap with. */
+ nrg = rg;
+ list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
+ if (&rg->link == head)
+ break;
+ if (rg->from > t)
+ break;
+
+ /* If this area reaches higher then extend our area to
+ * include it completely. If this is not the first area
+ * which we intend to reuse, free it. */
+ if (rg->to > t)
+ t = rg->to;
+ if (rg != nrg) {
+ list_del(&rg->link);
+ kfree(rg);
+ }
+ }
+ nrg->from = f;
+ nrg->to = t;
+ return 0;
+}
+
+static long region_chg(struct list_head *head, long f, long t)
+{
+ struct file_region *rg, *nrg;
+ long chg = 0;
+
+ /* Locate the region we are before or in. */
+ list_for_each_entry(rg, head, link)
+ if (f <= rg->to)
+ break;
+
+ /* 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 guarantee to record the reservation. */
+ if (&rg->link == head || t < rg->from) {
+ nrg = kmalloc(sizeof(*nrg), GFP_KERNEL);
+ if (!nrg)
+ return -ENOMEM;
+ nrg->from = f;
+ nrg->to = f;
+ INIT_LIST_HEAD(&nrg->link);
+ list_add(&nrg->link, rg->link.prev);
+
+ return t - f;
+ }
+
+ /* Round our left edge to the current segment if it encloses us. */
+ if (f > rg->from)
+ f = rg->from;
+ chg = t - f;
+
+ /* Check for and consume any regions we now overlap with. */
+ list_for_each_entry(rg, rg->link.prev, link) {
+ if (&rg->link == head)
+ break;
+ if (rg->from > t)
+ return chg;
+
+ /* We overlap with this area, if it extends futher than
+ * us then we must extend ourselves. Account for its
+ * existing reservation. */
+ if (rg->to > t) {
+ chg += rg->to - t;
+ t = rg->to;
+ }
+ chg -= rg->to - rg->from;
+ }
+ return chg;
+}
+
+static long region_truncate(struct list_head *head, long end)
+{
+ struct file_region *rg, *trg;
+ long chg = 0;
+
+ /* Locate the region we are either in or before. */
+ list_for_each_entry(rg, head, link)
+ if (end <= rg->to)
+ break;
+ if (&rg->link == head)
+ return 0;
+
+ /* If we are in the middle of a region then adjust it. */
+ if (end > rg->from) {
+ chg = rg->to - end;
+ rg->to = end;
+ rg = list_entry(rg->link.next, typeof(*rg), link);
+ }
+
+ /* Drop any remaining regions. */
+ list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
+ if (&rg->link == head)
+ break;
+ chg += rg->to - rg->from;
+ list_del(&rg->link);
+ kfree(rg);
+ }
+ return chg;
+}
+
+static long region_count(struct list_head *head, long f, long t)
+{
+ struct file_region *rg;
+ long chg = 0;
+
+ /* Locate each segment we overlap with, and count that overlap. */
+ list_for_each_entry(rg, head, link) {
+ int seg_from;
+ int seg_to;
+
+ if (rg->to <= f)
+ continue;
+ if (rg->from >= t)
+ break;
+
+ seg_from = max(rg->from, f);
+ seg_to = min(rg->to, t);
+
+ chg += seg_to - seg_from;
+ }
+
+ return chg;
+}
+
+/*
+ * Convert the address within this vma to the page offset within
+ * the mapping, in pagecache page units; huge pages here.
+ */
+static pgoff_t vma_hugecache_offset(struct hstate *h,
+ struct vm_area_struct *vma, unsigned long address)
+{
+ return ((address - vma->vm_start) >> huge_page_shift(h)) +
+ (vma->vm_pgoff >> huge_page_order(h));
+}
+
+/*
+ * 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.
+ */
+#define HPAGE_RESV_OWNER (1UL << 0)
+#define HPAGE_RESV_UNMAPPED (1UL << 1)
+#define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED)
+
+/*
+ * These helpers are used to track how many pages are reserved for
+ * faults in a MAP_PRIVATE mapping. Only the process that called mmap()
+ * is guaranteed to have their future faults succeed.
+ *
+ * With the exception of reset_vma_resv_huge_pages() which is called at fork(),
+ * the reserve counters are updated with the hugetlb_lock held. It is safe
+ * to reset the VMA at fork() time as it is not in use yet and there is no
+ * chance of the global counters getting corrupted as a result of the values.
+ *
+ * The private mapping reservation is represented in a subtly different
+ * manner to a shared mapping. A shared mapping has a region map associated
+ * with the underlying file, this region map represents the backing file
+ * pages which have ever had a reservation assigned which this persists even
+ * after the page is instantiated. A private mapping has a region map
+ * associated with the original mmap which is attached to all VMAs which
+ * reference it, this region map represents those offsets which have consumed
+ * reservation ie. where pages have been instantiated.
+ */
+static unsigned long get_vma_private_data(struct vm_area_struct *vma)
+{
+ return (unsigned long)vma->vm_private_data;
+}
+
+static void set_vma_private_data(struct vm_area_struct *vma,
+ unsigned long value)
+{
+ vma->vm_private_data = (void *)value;
+}
+
+struct resv_map {
+ struct kref refs;
+ struct list_head regions;
+};
+
+static struct resv_map *resv_map_alloc(void)
+{
+ struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL);
+ if (!resv_map)
+ return NULL;
+
+ kref_init(&resv_map->refs);
+ INIT_LIST_HEAD(&resv_map->regions);
+
+ return resv_map;
+}
+
+static void resv_map_release(struct kref *ref)
+{
+ struct resv_map *resv_map = container_of(ref, struct resv_map, refs);
+
+ /* Clear out any active regions before we release the map. */
+ region_truncate(&resv_map->regions, 0);
+ kfree(resv_map);
+}
+
+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_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_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_MAYSHARE);
+
+ set_vma_private_data(vma, get_vma_private_data(vma) | flags);
+}
+
+static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag)
+{
+ VM_BUG_ON(!is_vm_hugetlb_page(vma));
+
+ return (get_vma_private_data(vma) & flag) != 0;
+}
+
+/* Decrement the reserved pages in the hugepage pool by one */
+static void decrement_hugepage_resv_vma(struct hstate *h,
+ struct vm_area_struct *vma)
+{
+ if (vma->vm_flags & VM_NORESERVE)
+ return;
+
+ 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)) {
+ /*
+ * Only the process that called mmap() has reserves for
+ * private mappings.
+ */
+ h->resv_huge_pages--;
+ }
+}
+
+/* Reset counters to 0 and clear all HPAGE_RESV_* flags */
+void reset_vma_resv_huge_pages(struct vm_area_struct *vma)
+{
+ VM_BUG_ON(!is_vm_hugetlb_page(vma));
+ 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_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 < (HPAGE_SIZE/PAGE_SIZE); i++) {
+ for (i = 0; i < sz/PAGE_SIZE; i++) {
cond_resched();
clear_user_highpage(page + i, addr + i * PAGE_SIZE);
}
}
+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 < HPAGE_SIZE/PAGE_SIZE; i++) {
+ for (i = 0; i < pages_per_huge_page(h); i++) {
cond_resched();
copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma);
}
}
-static void enqueue_huge_page(struct page *page)
+static void enqueue_huge_page(struct hstate *h, struct page *page)
{
int nid = page_to_nid(page);
- list_add(&page->lru, &hugepage_freelists[nid]);
- free_huge_pages++;
- free_huge_pages_node[nid]++;
+ list_add(&page->lru, &h->hugepage_freelists[nid]);
+ h->free_huge_pages++;
+ h->free_huge_pages_node[nid]++;
}
-static struct page *dequeue_huge_page(void)
-{
- int nid;
- struct page *page = NULL;
-
- 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;
-}
-
-static struct page *dequeue_huge_page_vma(struct vm_area_struct *vma,
- unsigned long address)
+static struct page *dequeue_huge_page_vma(struct hstate *h,
+ struct vm_area_struct *vma,
+ unsigned long address, int avoid_reserve)
{
int nid;
struct page *page = NULL;
struct zone *zone;
struct zoneref *z;
+ /*
+ * A child process with MAP_PRIVATE mappings created by their parent
+ * have no page reserves. This check ensures that reservations are
+ * not "stolen". The child may still get SIGKILLed
+ */
+ if (!vma_has_reserves(vma) &&
+ h->free_huge_pages - h->resv_huge_pages == 0)
+ return NULL;
+
+ /* If reserves cannot be used, ensure enough pages are in the pool */
+ if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0)
+ return NULL;
+
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,
+ !list_empty(&h->hugepage_freelists[nid])) {
+ page = list_entry(h->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--;
+ h->free_huge_pages--;
+ h->free_huge_pages_node[nid]--;
+
+ if (!avoid_reserve)
+ decrement_hugepage_resv_vma(h, vma);
+
break;
}
}
- mpol_free(mpol); /* unref if mpol !NULL */
+ mpol_cond_put(mpol);
return page;
}
-static void update_and_free_page(struct page *page)
+static void update_and_free_page(struct hstate *h, 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++) {
+
+ 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++) {
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);
- __free_pages(page, HUGETLB_PAGE_ORDER);
+ arch_release_hugepage(page);
+ __free_pages(page, huge_page_order(h));
+}
+
+struct hstate *size_to_hstate(unsigned long size)
+{
+ struct hstate *h;
+
+ for_each_hstate(h) {
+ if (huge_page_size(h) == size)
+ return h;
+ }
+ return NULL;
}
static void free_huge_page(struct page *page)
{
+ /*
+ * Can't pass hstate in here because it is called from the
+ * compound page destructor.
+ */
+ struct hstate *h = page_hstate(page);
int nid = page_to_nid(page);
struct address_space *mapping;
INIT_LIST_HEAD(&page->lru);
spin_lock(&hugetlb_lock);
- if (surplus_huge_pages_node[nid]) {
- update_and_free_page(page);
- surplus_huge_pages--;
- surplus_huge_pages_node[nid]--;
+ if (h->surplus_huge_pages_node[nid] && huge_page_order(h) < MAX_ORDER) {
+ update_and_free_page(h, page);
+ h->surplus_huge_pages--;
+ h->surplus_huge_pages_node[nid]--;
} else {
- enqueue_huge_page(page);
+ enqueue_huge_page(h, page);
}
spin_unlock(&hugetlb_lock);
if (mapping)
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(int delta)
+static void prep_new_huge_page(struct hstate *h, struct page *page, int nid)
{
- static int prev_nid;
- int nid = prev_nid;
- int ret = 0;
+ set_compound_page_dtor(page, free_huge_page);
+ spin_lock(&hugetlb_lock);
+ h->nr_huge_pages++;
+ h->nr_huge_pages_node[nid]++;
+ spin_unlock(&hugetlb_lock);
+ put_page(page); /* free it into the hugepage allocator */
+}
- 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);
+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;
+ }
+}
- /* 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;
+int PageHuge(struct page *page)
+{
+ compound_page_dtor *dtor;
- surplus_huge_pages += delta;
- surplus_huge_pages_node[nid] += delta;
- ret = 1;
- break;
- } while (nid != prev_nid);
+ if (!PageCompound(page))
+ return 0;
- prev_nid = nid;
- return ret;
+ page = compound_head(page);
+ dtor = get_compound_page_dtor(page);
+
+ return dtor == free_huge_page;
}
-static struct page *alloc_fresh_huge_page_node(int nid)
+static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid)
{
struct page *page;
- page = alloc_pages_node(nid,
- htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|__GFP_NOWARN,
- HUGETLB_PAGE_ORDER);
+ if (h->order >= MAX_ORDER)
+ return NULL;
+
+ page = alloc_pages_exact_node(nid,
+ htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|
+ __GFP_REPEAT|__GFP_NOWARN,
+ huge_page_order(h));
if (page) {
- set_compound_page_dtor(page, free_huge_page);
- spin_lock(&hugetlb_lock);
- nr_huge_pages++;
- nr_huge_pages_node[nid]++;
- spin_unlock(&hugetlb_lock);
- put_page(page); /* free it into the hugepage allocator */
+ if (arch_prepare_hugepage(page)) {
+ __free_pages(page, huge_page_order(h));
+ return NULL;
+ }
+ prep_new_huge_page(h, page, nid);
}
return page;
}
-static int alloc_fresh_huge_page(void)
+/*
+ * Use a helper variable to find the next node and then
+ * 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_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_to_alloc(struct hstate *h)
+{
+ int next_nid;
+ 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->next_nid_to_alloc = next_nid;
+ return next_nid;
+}
+
+static int alloc_fresh_huge_page(struct hstate *h)
{
struct page *page;
int start_nid;
int next_nid;
int ret = 0;
- start_nid = hugetlb_next_nid;
+ start_nid = h->next_nid_to_alloc;
+ next_nid = start_nid;
do {
- page = alloc_fresh_huge_page_node(hugetlb_next_nid);
+ page = alloc_fresh_huge_page_node(h, next_nid);
if (page)
ret = 1;
+ next_nid = hstate_next_node_to_alloc(h);
+ } while (!page && next_nid != start_nid);
+
+ if (ret)
+ count_vm_event(HTLB_BUDDY_PGALLOC);
+ else
+ count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
+
+ 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 {
/*
- * 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.
+ * If we're returning unused surplus pages, only examine
+ * nodes with surplus pages.
*/
- 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 ((!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 vm_area_struct *vma,
- unsigned long address)
+static struct page *alloc_buddy_huge_page(struct hstate *h,
+ struct vm_area_struct *vma, unsigned long address)
{
struct page *page;
unsigned int nid;
+ if (h->order >= MAX_ORDER)
+ return NULL;
+
/*
* Assume we will successfully allocate the surplus page to
* prevent racing processes from causing the surplus to exceed
* per-node value is checked there.
*/
spin_lock(&hugetlb_lock);
- if (surplus_huge_pages >= nr_overcommit_huge_pages) {
+ if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) {
spin_unlock(&hugetlb_lock);
return NULL;
} else {
- nr_huge_pages++;
- surplus_huge_pages++;
+ h->nr_huge_pages++;
+ h->surplus_huge_pages++;
}
spin_unlock(&hugetlb_lock);
- page = alloc_pages(htlb_alloc_mask|__GFP_COMP|__GFP_NOWARN,
- HUGETLB_PAGE_ORDER);
+ page = alloc_pages(htlb_alloc_mask|__GFP_COMP|
+ __GFP_REPEAT|__GFP_NOWARN,
+ huge_page_order(h));
+
+ if (page && arch_prepare_hugepage(page)) {
+ __free_pages(page, huge_page_order(h));
+ return NULL;
+ }
spin_lock(&hugetlb_lock);
if (page) {
/*
* We incremented the global counters already
*/
- nr_huge_pages_node[nid]++;
- surplus_huge_pages_node[nid]++;
+ h->nr_huge_pages_node[nid]++;
+ h->surplus_huge_pages_node[nid]++;
+ __count_vm_event(HTLB_BUDDY_PGALLOC);
} else {
- nr_huge_pages--;
- surplus_huge_pages--;
+ h->nr_huge_pages--;
+ h->surplus_huge_pages--;
+ __count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
}
spin_unlock(&hugetlb_lock);
* Increase the hugetlb pool such that it can accomodate a reservation
* of size 'delta'.
*/
-static int gather_surplus_pages(int delta)
+static int gather_surplus_pages(struct hstate *h, 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;
+ needed = (h->resv_huge_pages + delta) - h->free_huge_pages;
if (needed <= 0) {
- resv_huge_pages += delta;
+ h->resv_huge_pages += delta;
return 0;
}
retry:
spin_unlock(&hugetlb_lock);
for (i = 0; i < needed; i++) {
- page = alloc_buddy_huge_page(NULL, 0);
+ page = alloc_buddy_huge_page(h, NULL, 0);
if (!page) {
/*
* We were not able to allocate enough pages to
* 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);
+ needed = (h->resv_huge_pages + delta) -
+ (h->free_huge_pages + allocated);
if (needed > 0)
goto retry;
* before they are reserved.
*/
needed += allocated;
- resv_huge_pages += delta;
+ h->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);
- if ((--needed) >= 0)
- enqueue_huge_page(page);
- else {
+ enqueue_huge_page(h, 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
* unlocked which is safe because free_huge_page takes
* hugetlb_lock before deciding how to free the page.
*/
- spin_unlock(&hugetlb_lock);
free_huge_page(page);
- spin_lock(&hugetlb_lock);
}
+ 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.
+ * Called with hugetlb_lock held.
*/
-static void return_unused_surplus_pages(unsigned long unused_resv_pages)
+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;
+ /* Uncommit the reservation */
+ h->resv_huge_pages -= unused_resv_pages;
+
+ /* Cannot return gigantic pages currently */
+ if (h->order >= MAX_ORDER)
+ return;
+
+ nr_pages = min(unused_resv_pages, h->surplus_huge_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.
+ * free_pool_huge_page() will balance the the frees across the
+ * on-line nodes for us and will handle the hstate accounting.
*/
- unsigned long remaining_iterations = num_online_nodes();
+ while (nr_pages--) {
+ if (!free_pool_huge_page(h, 1))
+ break;
+ }
+}
- /* Uncommit the reservation */
- resv_huge_pages -= unused_resv_pages;
+/*
+ * Determine if the huge page at addr within the vma has an associated
+ * reservation. Where it does not we will need to logically increase
+ * reservation and actually increase quota before an allocation can occur.
+ * Where any new reservation would be required the reservation change is
+ * prepared, but not committed. Once the page has been quota'd allocated
+ * an instantiated the change should be committed via vma_commit_reservation.
+ * No action is required on failure.
+ */
+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;
- nr_pages = min(unused_resv_pages, surplus_huge_pages);
+ 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);
- while (remaining_iterations-- && nr_pages) {
- nid = next_node(nid, node_online_map);
- if (nid == MAX_NUMNODES)
- nid = first_node(node_online_map);
+ } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
+ return 1;
- if (!surplus_huge_pages_node[nid])
- continue;
+ } else {
+ long err;
+ pgoff_t idx = vma_hugecache_offset(h, vma, addr);
+ struct resv_map *reservations = vma_resv_map(vma);
- 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();
- }
+ err = region_chg(&reservations->regions, idx, idx + 1);
+ if (err < 0)
+ return err;
+ return 0;
}
}
+static void vma_commit_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_MAYSHARE) {
+ pgoff_t idx = vma_hugecache_offset(h, vma, addr);
+ region_add(&inode->i_mapping->private_list, idx, idx + 1);
-static struct page *alloc_huge_page_shared(struct vm_area_struct *vma,
- unsigned long addr)
-{
- struct page *page;
+ } else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
+ pgoff_t idx = vma_hugecache_offset(h, vma, addr);
+ struct resv_map *reservations = vma_resv_map(vma);
- spin_lock(&hugetlb_lock);
- page = dequeue_huge_page_vma(vma, addr);
- spin_unlock(&hugetlb_lock);
- return page ? page : ERR_PTR(-VM_FAULT_OOM);
+ /* Mark this page used in the map. */
+ region_add(&reservations->regions, idx, idx + 1);
+ }
}
-static struct page *alloc_huge_page_private(struct vm_area_struct *vma,
- unsigned long addr)
+static struct page *alloc_huge_page(struct vm_area_struct *vma,
+ unsigned long addr, int avoid_reserve)
{
- struct page *page = NULL;
+ struct hstate *h = hstate_vma(vma);
+ struct page *page;
+ struct address_space *mapping = vma->vm_file->f_mapping;
+ struct inode *inode = mapping->host;
+ long chg;
- if (hugetlb_get_quota(vma->vm_file->f_mapping, 1))
- return ERR_PTR(-VM_FAULT_SIGBUS);
+ /*
+ * Processes that did not create the mapping will have no reserves and
+ * will not have accounted against quota. Check that the quota can be
+ * made before satisfying the allocation
+ * MAP_NORESERVE mappings may also need pages and quota allocated
+ * if no reserve mapping overlaps.
+ */
+ chg = vma_needs_reservation(h, vma, addr);
+ if (chg < 0)
+ return ERR_PTR(chg);
+ if (chg)
+ if (hugetlb_get_quota(inode->i_mapping, chg))
+ return ERR_PTR(-ENOSPC);
spin_lock(&hugetlb_lock);
- if (free_huge_pages > resv_huge_pages)
- page = dequeue_huge_page_vma(vma, addr);
+ page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve);
spin_unlock(&hugetlb_lock);
+
if (!page) {
- page = alloc_buddy_huge_page(vma, addr);
+ page = alloc_buddy_huge_page(h, vma, addr);
if (!page) {
- hugetlb_put_quota(vma->vm_file->f_mapping, 1);
+ hugetlb_put_quota(inode->i_mapping, chg);
return ERR_PTR(-VM_FAULT_OOM);
}
}
+
+ set_page_refcounted(page);
+ set_page_private(page, (unsigned long) mapping);
+
+ vma_commit_reservation(h, vma, addr);
+
return page;
}
-static struct page *alloc_huge_page(struct vm_area_struct *vma,
- unsigned long addr)
+int __weak alloc_bootmem_huge_page(struct hstate *h)
{
- struct page *page;
- struct address_space *mapping = vma->vm_file->f_mapping;
+ struct huge_bootmem_page *m;
+ int nr_nodes = nodes_weight(node_online_map);
- if (vma->vm_flags & VM_MAYSHARE)
- page = alloc_huge_page_shared(vma, addr);
- else
- page = alloc_huge_page_private(vma, addr);
+ while (nr_nodes) {
+ void *addr;
- if (!IS_ERR(page)) {
- set_page_refcounted(page);
- set_page_private(page, (unsigned long) mapping);
+ addr = __alloc_bootmem_node_nopanic(
+ 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
+ * huge_bootmem_page struct (until gather_bootmem
+ * puts them into the mem_map).
+ */
+ m = addr;
+ goto found;
+ }
+ nr_nodes--;
}
- return page;
+ return 0;
+
+found:
+ BUG_ON((unsigned long)virt_to_phys(m) & (huge_page_size(h) - 1));
+ /* Put them into a private list first because mem_map is not up yet */
+ list_add(&m->list, &huge_boot_pages);
+ m->hstate = h;
+ return 1;
}
-static int __init hugetlb_init(void)
+static void prep_compound_huge_page(struct page *page, int order)
{
- unsigned long i;
-
- if (HPAGE_SHIFT == 0)
- return 0;
+ if (unlikely(order > (MAX_ORDER - 1)))
+ prep_compound_gigantic_page(page, order);
+ else
+ prep_compound_page(page, order);
+}
- for (i = 0; i < MAX_NUMNODES; ++i)
- INIT_LIST_HEAD(&hugepage_freelists[i]);
+/* Put bootmem huge pages into the standard lists after mem_map is up */
+static void __init gather_bootmem_prealloc(void)
+{
+ struct huge_bootmem_page *m;
+
+ list_for_each_entry(m, &huge_boot_pages, list) {
+ struct page *page = virt_to_page(m);
+ struct hstate *h = m->hstate;
+ __ClearPageReserved(page);
+ WARN_ON(page_count(page) != 1);
+ prep_compound_huge_page(page, h->order);
+ prep_new_huge_page(h, page, page_to_nid(page));
+ }
+}
- hugetlb_next_nid = first_node(node_online_map);
+static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
+{
+ unsigned long i;
- for (i = 0; i < max_huge_pages; ++i) {
- if (!alloc_fresh_huge_page())
+ for (i = 0; i < h->max_huge_pages; ++i) {
+ if (h->order >= MAX_ORDER) {
+ if (!alloc_bootmem_huge_page(h))
+ break;
+ } else if (!alloc_fresh_huge_page(h))
break;
}
- max_huge_pages = free_huge_pages = nr_huge_pages = i;
- printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages);
- return 0;
+ h->max_huge_pages = i;
}
-module_init(hugetlb_init);
-static int __init hugetlb_setup(char *s)
+static void __init hugetlb_init_hstates(void)
{
- if (sscanf(s, "%lu", &max_huge_pages) <= 0)
- max_huge_pages = 0;
- return 1;
+ struct hstate *h;
+
+ for_each_hstate(h) {
+ /* oversize hugepages were init'ed in early boot */
+ if (h->order < MAX_ORDER)
+ hugetlb_hstate_alloc_pages(h);
+ }
}
-__setup("hugepages=", hugetlb_setup);
-static unsigned int cpuset_mems_nr(unsigned int *array)
+static char * __init memfmt(char *buf, unsigned long n)
{
- int node;
- unsigned int nr = 0;
-
- for_each_node_mask(node, cpuset_current_mems_allowed)
- nr += array[node];
+ if (n >= (1UL << 30))
+ sprintf(buf, "%lu GB", n >> 30);
+ else if (n >= (1UL << 20))
+ sprintf(buf, "%lu MB", n >> 20);
+ else
+ sprintf(buf, "%lu KB", n >> 10);
+ return buf;
+}
- return nr;
+static void __init report_hugepages(void)
+{
+ struct hstate *h;
+
+ for_each_hstate(h) {
+ char buf[32];
+ printk(KERN_INFO "HugeTLB registered %s page size, "
+ "pre-allocated %ld pages\n",
+ memfmt(buf, huge_page_size(h)),
+ h->free_huge_pages);
+ }
}
-#ifdef CONFIG_SYSCTL
#ifdef CONFIG_HIGHMEM
-static void try_to_free_low(unsigned long count)
+static void try_to_free_low(struct hstate *h, unsigned long count)
{
int i;
+ if (h->order >= MAX_ORDER)
+ return;
+
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)
+ struct list_head *freel = &h->hugepage_freelists[i];
+ list_for_each_entry_safe(page, next, freel, lru) {
+ if (count >= h->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)]--;
+ update_and_free_page(h, page);
+ h->free_huge_pages--;
+ h->free_huge_pages_node[page_to_nid(page)]--;
}
}
}
#else
-static inline void try_to_free_low(unsigned long count)
+static inline void try_to_free_low(struct hstate *h, unsigned long count)
{
}
#endif
-#define persistent_huge_pages (nr_huge_pages - surplus_huge_pages)
-static unsigned long set_max_huge_pages(unsigned long count)
+/*
+ * 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)
{
unsigned long min_count, ret;
+ if (h->order >= MAX_ORDER)
+ return h->max_huge_pages;
+
/*
* Increase the pool size
* First take pages out of surplus state. Then make up the
* within all the constraints specified by the sysctls.
*/
spin_lock(&hugetlb_lock);
- while (surplus_huge_pages && count > persistent_huge_pages) {
- if (!adjust_pool_surplus(-1))
+ while (h->surplus_huge_pages && count > persistent_huge_pages(h)) {
+ if (!adjust_pool_surplus(h, -1))
break;
}
- while (count > persistent_huge_pages) {
- int ret;
+ while (count > persistent_huge_pages(h)) {
/*
* 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();
+ ret = alloc_fresh_huge_page(h);
spin_lock(&hugetlb_lock);
if (!ret)
goto out;
* 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 = h->resv_huge_pages + h->nr_huge_pages - h->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)
+ try_to_free_low(h, min_count);
+ while (min_count < persistent_huge_pages(h)) {
+ if (!free_pool_huge_page(h, 0))
break;
- update_and_free_page(page);
}
- while (count < persistent_huge_pages) {
- if (!adjust_pool_surplus(1))
+ while (count < persistent_huge_pages(h)) {
+ if (!adjust_pool_surplus(h, 1))
break;
}
out:
- ret = persistent_huge_pages;
+ ret = persistent_huge_pages(h);
spin_unlock(&hugetlb_lock);
return ret;
}
+#define HSTATE_ATTR_RO(_name) \
+ static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
+
+#define HSTATE_ATTR(_name) \
+ static struct kobj_attribute _name##_attr = \
+ __ATTR(_name, 0644, _name##_show, _name##_store)
+
+static struct kobject *hugepages_kobj;
+static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE];
+
+static struct hstate *kobj_to_hstate(struct kobject *kobj)
+{
+ int i;
+ for (i = 0; i < HUGE_MAX_HSTATE; i++)
+ if (hstate_kobjs[i] == kobj)
+ return &hstates[i];
+ BUG();
+ return NULL;
+}
+
+static ssize_t nr_hugepages_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ struct hstate *h = kobj_to_hstate(kobj);
+ return sprintf(buf, "%lu\n", h->nr_huge_pages);
+}
+static ssize_t nr_hugepages_store(struct kobject *kobj,
+ struct kobj_attribute *attr, const char *buf, size_t count)
+{
+ int err;
+ unsigned long input;
+ struct hstate *h = kobj_to_hstate(kobj);
+
+ err = strict_strtoul(buf, 10, &input);
+ if (err)
+ return 0;
+
+ h->max_huge_pages = set_max_huge_pages(h, input);
+
+ return count;
+}
+HSTATE_ATTR(nr_hugepages);
+
+static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ struct hstate *h = kobj_to_hstate(kobj);
+ return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages);
+}
+static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj,
+ struct kobj_attribute *attr, const char *buf, size_t count)
+{
+ int err;
+ unsigned long input;
+ struct hstate *h = kobj_to_hstate(kobj);
+
+ err = strict_strtoul(buf, 10, &input);
+ if (err)
+ return 0;
+
+ spin_lock(&hugetlb_lock);
+ h->nr_overcommit_huge_pages = input;
+ spin_unlock(&hugetlb_lock);
+
+ return count;
+}
+HSTATE_ATTR(nr_overcommit_hugepages);
+
+static ssize_t free_hugepages_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ struct hstate *h = kobj_to_hstate(kobj);
+ return sprintf(buf, "%lu\n", h->free_huge_pages);
+}
+HSTATE_ATTR_RO(free_hugepages);
+
+static ssize_t resv_hugepages_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ struct hstate *h = kobj_to_hstate(kobj);
+ return sprintf(buf, "%lu\n", h->resv_huge_pages);
+}
+HSTATE_ATTR_RO(resv_hugepages);
+
+static ssize_t surplus_hugepages_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ struct hstate *h = kobj_to_hstate(kobj);
+ return sprintf(buf, "%lu\n", h->surplus_huge_pages);
+}
+HSTATE_ATTR_RO(surplus_hugepages);
+
+static struct attribute *hstate_attrs[] = {
+ &nr_hugepages_attr.attr,
+ &nr_overcommit_hugepages_attr.attr,
+ &free_hugepages_attr.attr,
+ &resv_hugepages_attr.attr,
+ &surplus_hugepages_attr.attr,
+ NULL,
+};
+
+static struct attribute_group hstate_attr_group = {
+ .attrs = hstate_attrs,
+};
+
+static int __init hugetlb_sysfs_add_hstate(struct hstate *h)
+{
+ int retval;
+
+ hstate_kobjs[h - hstates] = kobject_create_and_add(h->name,
+ hugepages_kobj);
+ if (!hstate_kobjs[h - hstates])
+ return -ENOMEM;
+
+ retval = sysfs_create_group(hstate_kobjs[h - hstates],
+ &hstate_attr_group);
+ if (retval)
+ kobject_put(hstate_kobjs[h - hstates]);
+
+ return retval;
+}
+
+static void __init hugetlb_sysfs_init(void)
+{
+ struct hstate *h;
+ int err;
+
+ hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj);
+ if (!hugepages_kobj)
+ return;
+
+ for_each_hstate(h) {
+ err = hugetlb_sysfs_add_hstate(h);
+ if (err)
+ printk(KERN_ERR "Hugetlb: Unable to add hstate %s",
+ h->name);
+ }
+}
+
+static void __exit hugetlb_exit(void)
+{
+ struct hstate *h;
+
+ for_each_hstate(h) {
+ kobject_put(hstate_kobjs[h - hstates]);
+ }
+
+ kobject_put(hugepages_kobj);
+}
+module_exit(hugetlb_exit);
+
+static int __init hugetlb_init(void)
+{
+ /* Some platform decide whether they support huge pages at boot
+ * time. On these, such as powerpc, HPAGE_SHIFT is set to 0 when
+ * there is no such support
+ */
+ if (HPAGE_SHIFT == 0)
+ return 0;
+
+ if (!size_to_hstate(default_hstate_size)) {
+ default_hstate_size = HPAGE_SIZE;
+ if (!size_to_hstate(default_hstate_size))
+ hugetlb_add_hstate(HUGETLB_PAGE_ORDER);
+ }
+ default_hstate_idx = size_to_hstate(default_hstate_size) - hstates;
+ if (default_hstate_max_huge_pages)
+ default_hstate.max_huge_pages = default_hstate_max_huge_pages;
+
+ hugetlb_init_hstates();
+
+ gather_bootmem_prealloc();
+
+ report_hugepages();
+
+ hugetlb_sysfs_init();
+
+ return 0;
+}
+module_init(hugetlb_init);
+
+/* Should be called on processing a hugepagesz=... option */
+void __init hugetlb_add_hstate(unsigned order)
+{
+ struct hstate *h;
+ unsigned long i;
+
+ if (size_to_hstate(PAGE_SIZE << order)) {
+ printk(KERN_WARNING "hugepagesz= specified twice, ignoring\n");
+ return;
+ }
+ BUG_ON(max_hstate >= HUGE_MAX_HSTATE);
+ BUG_ON(order == 0);
+ h = &hstates[max_hstate++];
+ h->order = order;
+ h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1);
+ h->nr_huge_pages = 0;
+ h->free_huge_pages = 0;
+ for (i = 0; i < MAX_NUMNODES; ++i)
+ INIT_LIST_HEAD(&h->hugepage_freelists[i]);
+ 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);
+
+ parsed_hstate = h;
+}
+
+static int __init hugetlb_nrpages_setup(char *s)
+{
+ unsigned long *mhp;
+ static unsigned long *last_mhp;
+
+ /*
+ * !max_hstate means we haven't parsed a hugepagesz= parameter yet,
+ * so this hugepages= parameter goes to the "default hstate".
+ */
+ if (!max_hstate)
+ mhp = &default_hstate_max_huge_pages;
+ else
+ mhp = &parsed_hstate->max_huge_pages;
+
+ if (mhp == last_mhp) {
+ printk(KERN_WARNING "hugepages= specified twice without "
+ "interleaving hugepagesz=, ignoring\n");
+ return 1;
+ }
+
+ if (sscanf(s, "%lu", mhp) <= 0)
+ *mhp = 0;
+
+ /*
+ * Global state is always initialized later in hugetlb_init.
+ * But we need to allocate >= MAX_ORDER hstates here early to still
+ * use the bootmem allocator.
+ */
+ if (max_hstate && parsed_hstate->order >= MAX_ORDER)
+ hugetlb_hstate_alloc_pages(parsed_hstate);
+
+ last_mhp = mhp;
+
+ return 1;
+}
+__setup("hugepages=", hugetlb_nrpages_setup);
+
+static int __init hugetlb_default_setup(char *s)
+{
+ default_hstate_size = memparse(s, &s);
+ return 1;
+}
+__setup("default_hugepagesz=", hugetlb_default_setup);
+
+static unsigned int cpuset_mems_nr(unsigned int *array)
+{
+ int node;
+ unsigned int nr = 0;
+
+ for_each_node_mask(node, cpuset_current_mems_allowed)
+ nr += array[node];
+
+ return nr;
+}
+
+#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)
{
- proc_doulongvec_minmax(table, write, file, buffer, length, ppos);
- max_huge_pages = set_max_huge_pages(max_huge_pages);
+ struct hstate *h = &default_hstate;
+ unsigned long tmp;
+
+ if (!write)
+ tmp = h->max_huge_pages;
+
+ table->data = &tmp;
+ table->maxlen = sizeof(unsigned long);
+ proc_doulongvec_minmax(table, write, buffer, length, ppos);
+
+ if (write)
+ h->max_huge_pages = set_max_huge_pages(h, tmp);
+
return 0;
}
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)
{
- 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);
+ struct hstate *h = &default_hstate;
+ unsigned long tmp;
+
+ if (!write)
+ tmp = h->nr_overcommit_huge_pages;
+
+ table->data = &tmp;
+ table->maxlen = sizeof(unsigned long);
+ proc_doulongvec_minmax(table, write, buffer, length, ppos);
+
+ if (write) {
+ spin_lock(&hugetlb_lock);
+ h->nr_overcommit_huge_pages = tmp;
+ spin_unlock(&hugetlb_lock);
+ }
+
return 0;
}
#endif /* CONFIG_SYSCTL */
-int hugetlb_report_meminfo(char *buf)
+void hugetlb_report_meminfo(struct seq_file *m)
{
- return sprintf(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);
+ struct hstate *h = &default_hstate;
+ seq_printf(m,
+ "HugePages_Total: %5lu\n"
+ "HugePages_Free: %5lu\n"
+ "HugePages_Rsvd: %5lu\n"
+ "HugePages_Surp: %5lu\n"
+ "Hugepagesize: %8lu kB\n",
+ h->nr_huge_pages,
+ h->free_huge_pages,
+ h->resv_huge_pages,
+ h->surplus_huge_pages,
+ 1UL << (huge_page_order(h) + PAGE_SHIFT - 10));
}
int hugetlb_report_node_meminfo(int nid, char *buf)
{
+ struct hstate *h = &default_hstate;
return sprintf(buf,
"Node %d HugePages_Total: %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, surplus_huge_pages_node[nid]);
+ nid, h->nr_huge_pages_node[nid],
+ nid, h->free_huge_pages_node[nid],
+ nid, h->surplus_huge_pages_node[nid]);
}
/* Return the number pages of memory we physically have, in PAGE_SIZE units. */
unsigned long hugetlb_total_pages(void)
{
- return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE);
+ struct hstate *h = &default_hstate;
+ return h->nr_huge_pages * pages_per_huge_page(h);
+}
+
+static int hugetlb_acct_memory(struct hstate *h, long delta)
+{
+ int ret = -ENOMEM;
+
+ spin_lock(&hugetlb_lock);
+ /*
+ * 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(h, delta) < 0)
+ goto out;
+
+ if (delta > cpuset_mems_nr(h->free_huge_pages_node)) {
+ return_unused_surplus_pages(h, delta);
+ goto out;
+ }
+ }
+
+ ret = 0;
+ if (delta < 0)
+ return_unused_surplus_pages(h, (unsigned long) -delta);
+
+out:
+ spin_unlock(&hugetlb_lock);
+ return ret;
+}
+
+static void hugetlb_vm_op_open(struct vm_area_struct *vma)
+{
+ struct resv_map *reservations = vma_resv_map(vma);
+
+ /*
+ * This new VMA should share its siblings reservation map if present.
+ * The VMA will only ever have a valid reservation map pointer where
+ * it is being copied for another still existing VMA. As that VMA
+ * has a reference to the reservation map it cannot dissappear until
+ * after this open call completes. It is therefore safe to take a
+ * new reference here without additional locking.
+ */
+ if (reservations)
+ kref_get(&reservations->refs);
+}
+
+static void hugetlb_vm_op_close(struct vm_area_struct *vma)
+{
+ struct hstate *h = hstate_vma(vma);
+ struct resv_map *reservations = vma_resv_map(vma);
+ unsigned long reserve;
+ unsigned long start;
+ unsigned long end;
+
+ if (reservations) {
+ start = vma_hugecache_offset(h, vma, vma->vm_start);
+ end = vma_hugecache_offset(h, vma, vma->vm_end);
+
+ reserve = (end - start) -
+ region_count(&reservations->regions, start, end);
+
+ kref_put(&reservations->refs, resv_map_release);
+
+ if (reserve) {
+ hugetlb_acct_memory(h, -reserve);
+ hugetlb_put_quota(vma->vm_file->f_mapping, reserve);
+ }
+ }
}
/*
struct vm_operations_struct hugetlb_vm_ops = {
.fault = hugetlb_vm_op_fault,
+ .open = hugetlb_vm_op_open,
+ .close = hugetlb_vm_op_close,
};
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));
- if (ptep_set_access_flags(vma, address, ptep, entry, 1)) {
+ 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);
}
}
struct page *ptepage;
unsigned long addr;
int cow;
+ struct hstate *h = hstate_vma(vma);
+ unsigned long sz = huge_page_size(h);
cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
- for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) {
+ for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) {
src_pte = huge_pte_offset(src, addr);
if (!src_pte)
continue;
- dst_pte = huge_pte_alloc(dst, addr);
+ dst_pte = huge_pte_alloc(dst, addr, sz);
if (!dst_pte)
goto nomem;
continue;
spin_lock(&dst->page_table_lock);
- spin_lock(&src->page_table_lock);
- if (!pte_none(*src_pte)) {
+ spin_lock_nested(&src->page_table_lock, SINGLE_DEPTH_NESTING);
+ 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);
set_huge_pte_at(dst, addr, dst_pte, entry);
}
void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
- unsigned long end)
+ unsigned long end, struct page *ref_page)
{
struct mm_struct *mm = vma->vm_mm;
unsigned long address;
pte_t pte;
struct page *page;
struct page *tmp;
+ struct hstate *h = hstate_vma(vma);
+ unsigned long sz = huge_page_size(h);
+
/*
* A page gathering list, protected by per file i_mmap_lock. The
* lock is used to avoid list corruption from multiple unmapping
LIST_HEAD(page_list);
WARN_ON(!is_vm_hugetlb_page(vma));
- BUG_ON(start & ~HPAGE_MASK);
- BUG_ON(end & ~HPAGE_MASK);
+ BUG_ON(start & ~huge_page_mask(h));
+ BUG_ON(end & ~huge_page_mask(h));
+ mmu_notifier_invalidate_range_start(mm, start, end);
spin_lock(&mm->page_table_lock);
- for (address = start; address < end; address += HPAGE_SIZE) {
+ for (address = start; address < end; address += sz) {
ptep = huge_pte_offset(mm, address);
if (!ptep)
continue;
if (huge_pmd_unshare(mm, &address, ptep))
continue;
+ /*
+ * If a reference page is supplied, it is because a specific
+ * page is being unmapped, not a range. Ensure the page we
+ * are about to unmap is the actual page of interest.
+ */
+ if (ref_page) {
+ pte = huge_ptep_get(ptep);
+ if (huge_pte_none(pte))
+ continue;
+ page = pte_page(pte);
+ if (page != ref_page)
+ continue;
+
+ /*
+ * Mark the VMA as having unmapped its page so that
+ * future faults in this VMA will fail rather than
+ * looking like data was lost
+ */
+ set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED);
+ }
+
pte = huge_ptep_get_and_clear(mm, address, ptep);
- if (pte_none(pte))
+ if (huge_pte_none(pte))
continue;
page = pte_page(pte);
}
spin_unlock(&mm->page_table_lock);
flush_tlb_range(vma, start, end);
+ mmu_notifier_invalidate_range_end(mm, 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)
+ unsigned long end, struct page *ref_page)
{
+ spin_lock(&vma->vm_file->f_mapping->i_mmap_lock);
+ __unmap_hugepage_range(vma, start, end, ref_page);
+ spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock);
+}
+
+/*
+ * This is called when the original mapper is failing to COW a MAP_PRIVATE
+ * mappping it owns the reserve page for. The intention is to unmap the page
+ * from other VMAs and let the children be SIGKILLed if they are faulting the
+ * same region.
+ */
+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;
+ pgoff_t pgoff;
+
/*
- * 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.
+ * vm_pgoff is in PAGE_SIZE units, hence the different calculation
+ * from page cache lookup which is in HPAGE_SIZE units.
*/
- 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);
+ 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);
+
+ vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
+ /* Do not unmap the current VMA */
+ if (iter_vma == vma)
+ continue;
+
+ /*
+ * Unmap the page from other VMAs without their own reserves.
+ * They get marked to be SIGKILLed if they fault in these
+ * areas. This is because a future no-page fault on this VMA
+ * could insert a zeroed page instead of the data existing
+ * from the time of fork. This would look like data corruption
+ */
+ if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER))
+ unmap_hugepage_range(iter_vma,
+ address, address + huge_page_size(h),
+ page);
}
+
+ return 1;
}
static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long address, pte_t *ptep, pte_t pte)
+ unsigned long address, pte_t *ptep, pte_t pte,
+ struct page *pagecache_page)
{
+ struct hstate *h = hstate_vma(vma);
struct page *old_page, *new_page;
int avoidcopy;
+ int outside_reserve = 0;
old_page = pte_page(pte);
+retry_avoidcopy:
/* If no-one else is actually using this page, avoid the copy
* and just make the page writable */
avoidcopy = (page_count(old_page) == 1);
return 0;
}
+ /*
+ * If the process that created a MAP_PRIVATE mapping is about to
+ * perform a COW due to a shared page count, attempt to satisfy
+ * the allocation without using the existing reserves. The pagecache
+ * page is used to determine if the reserve at this address was
+ * consumed or not. If reserves were used, a partial faulted mapping
+ * 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) &&
+ old_page != pagecache_page)
+ outside_reserve = 1;
+
page_cache_get(old_page);
- new_page = alloc_huge_page(vma, address);
+ new_page = alloc_huge_page(vma, address, outside_reserve);
if (IS_ERR(new_page)) {
page_cache_release(old_page);
+
+ /*
+ * If a process owning a MAP_PRIVATE mapping fails to COW,
+ * it is due to references held by a child and an insufficient
+ * huge page pool. To guarantee the original mappers
+ * reliability, unmap the page from child processes. The child
+ * may get SIGKILLed if it later faults.
+ */
+ if (outside_reserve) {
+ BUG_ON(huge_pte_none(pte));
+ if (unmap_ref_private(mm, vma, old_page, address)) {
+ BUG_ON(page_count(old_page) != 1);
+ BUG_ON(huge_pte_none(pte));
+ goto retry_avoidcopy;
+ }
+ WARN_ON_ONCE(1);
+ }
+
return -PTR_ERR(new_page);
}
__SetPageUptodate(new_page);
spin_lock(&mm->page_table_lock);
- ptep = huge_pte_offset(mm, address & HPAGE_MASK);
- if (likely(pte_same(*ptep, pte))) {
+ ptep = huge_pte_offset(mm, address & huge_page_mask(h));
+ 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 */
return 0;
}
+/* Return the pagecache page at a given address within a VMA */
+static struct page *hugetlbfs_pagecache_page(struct hstate *h,
+ struct vm_area_struct *vma, unsigned long address)
+{
+ struct address_space *mapping;
+ pgoff_t idx;
+
+ mapping = vma->vm_file->f_mapping;
+ idx = vma_hugecache_offset(h, vma, address);
+
+ 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;
- unsigned long idx;
+ pgoff_t idx;
unsigned long size;
struct page *page;
struct address_space *mapping;
pte_t new_pte;
+ /*
+ * Currently, we are forced to kill the process in the event the
+ * original mapper has unmapped pages from the child due to a failed
+ * COW. Warn that such a situation has occured as it may not be obvious
+ */
+ if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) {
+ printk(KERN_WARNING
+ "PID %d killed due to inadequate hugepage pool\n",
+ current->pid);
+ return ret;
+ }
+
mapping = vma->vm_file->f_mapping;
- idx = ((address - vma->vm_start) >> HPAGE_SHIFT)
- + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT));
+ idx = vma_hugecache_offset(h, vma, address);
/*
* Use page lock to guard against racing truncation
retry:
page = find_lock_page(mapping, idx);
if (!page) {
- size = i_size_read(mapping->host) >> HPAGE_SHIFT;
+ size = i_size_read(mapping->host) >> huge_page_shift(h);
if (idx >= size)
goto out;
- page = alloc_huge_page(vma, address);
+ page = alloc_huge_page(vma, address, 0);
if (IS_ERR(page)) {
ret = -PTR_ERR(page);
goto out;
}
- clear_huge_page(page, address);
+ 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;
}
spin_lock(&inode->i_lock);
- inode->i_blocks += BLOCKS_PER_HUGEPAGE;
+ inode->i_blocks += blocks_per_huge_page(h);
spin_unlock(&inode->i_lock);
} else
lock_page(page);
}
+ /*
+ * If we are going to COW a private mapping later, we examine the
+ * pending reservations for this page now. This will ensure that
+ * any allocations necessary to record that reservation occur outside
+ * the spinlock.
+ */
+ 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;
+ }
+
spin_lock(&mm->page_table_lock);
- size = i_size_read(mapping->host) >> HPAGE_SHIFT;
+ size = i_size_read(mapping->host) >> huge_page_shift(h);
if (idx >= size)
goto backout;
ret = 0;
- if (!pte_none(*ptep))
+ if (!huge_pte_none(huge_ptep_get(ptep)))
goto backout;
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)) {
+ 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);
+ ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page);
}
spin_unlock(&mm->page_table_lock);
backout:
spin_unlock(&mm->page_table_lock);
+backout_unlocked:
unlock_page(page);
put_page(page);
goto out;
}
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;
int ret;
+ struct page *pagecache_page = NULL;
static DEFINE_MUTEX(hugetlb_instantiation_mutex);
+ struct hstate *h = hstate_vma(vma);
- ptep = huge_pte_alloc(mm, address);
+ ptep = huge_pte_alloc(mm, address, huge_page_size(h));
if (!ptep)
return VM_FAULT_OOM;
* the same page in the page cache.
*/
mutex_lock(&hugetlb_instantiation_mutex);
- entry = *ptep;
- if (pte_none(entry)) {
- ret = hugetlb_no_page(mm, vma, address, ptep, write_access);
- mutex_unlock(&hugetlb_instantiation_mutex);
- return ret;
+ entry = huge_ptep_get(ptep);
+ if (huge_pte_none(entry)) {
+ ret = hugetlb_no_page(mm, vma, address, ptep, flags);
+ goto out_mutex;
}
ret = 0;
+ /*
+ * If we are going to COW the mapping later, we examine the pending
+ * reservations for this page now. This will ensure that any
+ * allocations necessary to record that reservation occur outside the
+ * spinlock. For private mappings, we also lookup the pagecache
+ * page now as it is used to determine if a reservation has been
+ * consumed.
+ */
+ 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_MAYSHARE))
+ pagecache_page = hugetlbfs_pagecache_page(h,
+ vma, address);
+ }
+
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);
+ if (unlikely(!pte_same(entry, huge_ptep_get(ptep))))
+ goto out_page_table_lock;
+
+
+ if (flags & FAULT_FLAG_WRITE) {
+ if (!pte_write(entry)) {
+ ret = hugetlb_cow(mm, vma, address, ptep, entry,
+ pagecache_page);
+ goto out_page_table_lock;
+ }
+ entry = pte_mkdirty(entry);
+ }
+ entry = pte_mkyoung(entry);
+ if (huge_ptep_set_access_flags(vma, address, ptep, entry,
+ flags & FAULT_FLAG_WRITE))
+ update_mmu_cache(vma, address, entry);
+
+out_page_table_lock:
spin_unlock(&mm->page_table_lock);
+
+ if (pagecache_page) {
+ unlock_page(pagecache_page);
+ put_page(pagecache_page);
+ }
+
+out_mutex:
mutex_unlock(&hugetlb_instantiation_mutex);
return ret;
}
+/* Can be overriden by architectures */
+__attribute__((weak)) struct page *
+follow_huge_pud(struct mm_struct *mm, unsigned long address,
+ pud_t *pud, int write)
+{
+ BUG();
+ return NULL;
+}
+
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);
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 & HPAGE_MASK);
+ pte = huge_pte_offset(mm, vaddr & huge_page_mask(h));
+ absent = !pte || huge_pte_none(huge_ptep_get(pte));
- if (!pte || pte_none(*pte) || (write && !pte_write(*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;
}
- pfn_offset = (vaddr & ~HPAGE_MASK) >> PAGE_SHIFT;
- page = pte_page(*pte);
+ pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT;
+ page = pte_page(huge_ptep_get(pte));
same_page:
if (pages) {
- get_page(page);
- pages[i] = page + pfn_offset;
+ pages[i] = mem_map_offset(page, pfn_offset);
+ get_page(pages[i]);
}
if (vmas)
--remainder;
++i;
if (vaddr < vma->vm_end && remainder &&
- pfn_offset < HPAGE_SIZE/PAGE_SIZE) {
+ pfn_offset < pages_per_huge_page(h)) {
/*
* We use pfn_offset to avoid touching the pageframes
* of this compound page.
*length = remainder;
*position = vaddr;
- return i;
+ return i ? i : -EFAULT;
}
void hugetlb_change_protection(struct vm_area_struct *vma,
unsigned long start = address;
pte_t *ptep;
pte_t pte;
+ struct hstate *h = hstate_vma(vma);
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) {
+ for (; address < end; address += huge_page_size(h)) {
ptep = huge_pte_offset(mm, address);
if (!ptep)
continue;
if (huge_pmd_unshare(mm, &address, ptep))
continue;
- if (!pte_none(*ptep)) {
+ 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);
flush_tlb_range(vma, start, end);
}
-struct file_region {
- struct list_head link;
- long from;
- long to;
-};
-
-static long region_add(struct list_head *head, long f, long t)
-{
- struct file_region *rg, *nrg, *trg;
-
- /* Locate the region we are either in or before. */
- list_for_each_entry(rg, head, link)
- if (f <= rg->to)
- break;
-
- /* Round our left edge to the current segment if it encloses us. */
- if (f > rg->from)
- f = rg->from;
-
- /* Check for and consume any regions we now overlap with. */
- nrg = rg;
- list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
- if (&rg->link == head)
- break;
- if (rg->from > t)
- break;
-
- /* If this area reaches higher then extend our area to
- * include it completely. If this is not the first area
- * which we intend to reuse, free it. */
- if (rg->to > t)
- t = rg->to;
- if (rg != nrg) {
- list_del(&rg->link);
- kfree(rg);
- }
- }
- nrg->from = f;
- nrg->to = t;
- return 0;
-}
-
-static long region_chg(struct list_head *head, long f, long t)
-{
- struct file_region *rg, *nrg;
- long chg = 0;
-
- /* Locate the region we are before or in. */
- list_for_each_entry(rg, head, link)
- if (f <= rg->to)
- break;
-
- /* 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 guarantee to record the reservation. */
- if (&rg->link == head || t < rg->from) {
- nrg = kmalloc(sizeof(*nrg), GFP_KERNEL);
- if (!nrg)
- return -ENOMEM;
- nrg->from = f;
- nrg->to = f;
- INIT_LIST_HEAD(&nrg->link);
- list_add(&nrg->link, rg->link.prev);
-
- return t - f;
- }
-
- /* Round our left edge to the current segment if it encloses us. */
- if (f > rg->from)
- f = rg->from;
- chg = t - f;
-
- /* Check for and consume any regions we now overlap with. */
- list_for_each_entry(rg, rg->link.prev, link) {
- if (&rg->link == head)
- break;
- if (rg->from > t)
- return chg;
-
- /* We overlap with this area, if it extends futher than
- * us then we must extend ourselves. Account for its
- * existing reservation. */
- if (rg->to > t) {
- chg += rg->to - t;
- t = rg->to;
- }
- chg -= rg->to - rg->from;
- }
- return chg;
-}
-
-static long region_truncate(struct list_head *head, long end)
+int hugetlb_reserve_pages(struct inode *inode,
+ long from, long to,
+ struct vm_area_struct *vma,
+ int acctflag)
{
- struct file_region *rg, *trg;
- long chg = 0;
+ long ret, chg;
+ struct hstate *h = hstate_inode(inode);
- /* Locate the region we are either in or before. */
- list_for_each_entry(rg, head, link)
- if (end <= rg->to)
- break;
- if (&rg->link == head)
+ /*
+ * 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;
- /* If we are in the middle of a region then adjust it. */
- if (end > rg->from) {
- chg = rg->to - end;
- rg->to = end;
- rg = list_entry(rg->link.next, typeof(*rg), link);
- }
-
- /* Drop any remaining regions. */
- list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
- if (&rg->link == head)
- break;
- chg += rg->to - rg->from;
- list_del(&rg->link);
- kfree(rg);
- }
- return chg;
-}
-
-static int hugetlb_acct_memory(long delta)
-{
- int ret = -ENOMEM;
-
- spin_lock(&hugetlb_lock);
/*
- * 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.
+ * Shared mappings base their reservation on the number of pages that
+ * are already allocated on behalf of the file. Private mappings need
+ * 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 (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);
+ 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 (!resv_map)
+ return -ENOMEM;
-out:
- spin_unlock(&hugetlb_lock);
- return ret;
-}
+ chg = to - from;
-int hugetlb_reserve_pages(struct inode *inode, long from, long to)
-{
- long ret, chg;
+ set_vma_resv_map(vma, resv_map);
+ set_vma_resv_flags(vma, HPAGE_RESV_OWNER);
+ }
- chg = region_chg(&inode->i_mapping->private_list, from, to);
if (chg < 0)
return chg;
+ /* There must be enough filesystem quota for the mapping */
if (hugetlb_get_quota(inode->i_mapping, chg))
return -ENOSPC;
- ret = hugetlb_acct_memory(chg);
+
+ /*
+ * 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;
}
- region_add(&inode->i_mapping->private_list, from, to);
+
+ /*
+ * 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;
}
void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed)
{
+ struct hstate *h = hstate_inode(inode);
long chg = region_truncate(&inode->i_mapping->private_list, offset);
spin_lock(&inode->i_lock);
- inode->i_blocks -= BLOCKS_PER_HUGEPAGE * freed;
+ inode->i_blocks -= (blocks_per_huge_page(h) * freed);
spin_unlock(&inode->i_lock);
hugetlb_put_quota(inode->i_mapping, (chg - freed));
- hugetlb_acct_memory(-(chg - freed));
+ hugetlb_acct_memory(h, -(chg - freed));
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff