mm: correct page->pfmemalloc to fix deactivate_slab regression
[pandora-kernel.git] / mm / hugetlb.c
index e198831..bc72712 100644 (file)
 
 #include <asm/page.h>
 #include <asm/pgtable.h>
-#include <linux/io.h>
+#include <asm/tlb.h>
 
+#include <linux/io.h>
 #include <linux/hugetlb.h>
+#include <linux/hugetlb_cgroup.h>
 #include <linux/node.h>
+#include <linux/hugetlb_cgroup.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;
 
-static int max_hstate;
+int hugetlb_max_hstate __read_mostly;
 unsigned int default_hstate_idx;
 struct hstate hstates[HUGE_MAX_HSTATE];
 
@@ -45,13 +48,10 @@ 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);
+DEFINE_SPINLOCK(hugetlb_lock);
 
 static inline void unlock_or_release_subpool(struct hugepage_subpool *spool)
 {
@@ -509,7 +509,7 @@ void copy_huge_page(struct page *dst, struct page *src)
 static void enqueue_huge_page(struct hstate *h, struct page *page)
 {
        int nid = page_to_nid(page);
-       list_add(&page->lru, &h->hugepage_freelists[nid]);
+       list_move(&page->lru, &h->hugepage_freelists[nid]);
        h->free_huge_pages++;
        h->free_huge_pages_node[nid]++;
 }
@@ -521,7 +521,7 @@ static struct page *dequeue_huge_page_node(struct hstate *h, int nid)
        if (list_empty(&h->hugepage_freelists[nid]))
                return NULL;
        page = list_entry(h->hugepage_freelists[nid].next, struct page, lru);
-       list_del(&page->lru);
+       list_move(&page->lru, &h->hugepage_activelist);
        set_page_refcounted(page);
        h->free_huge_pages--;
        h->free_huge_pages_node[nid]--;
@@ -593,6 +593,7 @@ static void update_and_free_page(struct hstate *h, struct page *page)
                                1 << PG_active | 1 << PG_reserved |
                                1 << PG_private | 1 << PG_writeback);
        }
+       VM_BUG_ON(hugetlb_cgroup_from_page(page));
        set_compound_page_dtor(page, NULL);
        set_page_refcounted(page);
        arch_release_hugepage(page);
@@ -625,10 +626,13 @@ static void free_huge_page(struct page *page)
        page->mapping = NULL;
        BUG_ON(page_count(page));
        BUG_ON(page_mapcount(page));
-       INIT_LIST_HEAD(&page->lru);
 
        spin_lock(&hugetlb_lock);
+       hugetlb_cgroup_uncharge_page(hstate_index(h),
+                                    pages_per_huge_page(h), page);
        if (h->surplus_huge_pages_node[nid] && huge_page_order(h) < MAX_ORDER) {
+               /* remove the page from active list */
+               list_del(&page->lru);
                update_and_free_page(h, page);
                h->surplus_huge_pages--;
                h->surplus_huge_pages_node[nid]--;
@@ -641,8 +645,10 @@ static void free_huge_page(struct page *page)
 
 static void prep_new_huge_page(struct hstate *h, struct page *page, int nid)
 {
+       INIT_LIST_HEAD(&page->lru);
        set_compound_page_dtor(page, free_huge_page);
        spin_lock(&hugetlb_lock);
+       set_hugetlb_cgroup(page, NULL);
        h->nr_huge_pages++;
        h->nr_huge_pages_node[nid]++;
        spin_unlock(&hugetlb_lock);
@@ -889,8 +895,10 @@ static struct page *alloc_buddy_huge_page(struct hstate *h, int nid)
 
        spin_lock(&hugetlb_lock);
        if (page) {
+               INIT_LIST_HEAD(&page->lru);
                r_nid = page_to_nid(page);
                set_compound_page_dtor(page, free_huge_page);
+               set_hugetlb_cgroup(page, NULL);
                /*
                 * We incremented the global counters already
                 */
@@ -993,7 +1001,6 @@ retry:
        list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
                if ((--needed) < 0)
                        break;
-               list_del(&page->lru);
                /*
                 * This page is now managed by the hugetlb allocator and has
                 * no users -- drop the buddy allocator's reference.
@@ -1008,7 +1015,6 @@ free:
        /* Free unnecessary surplus pages to the buddy allocator */
        if (!list_empty(&surplus_list)) {
                list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
-                       list_del(&page->lru);
                        put_page(page);
                }
        }
@@ -1112,7 +1118,10 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma,
        struct hstate *h = hstate_vma(vma);
        struct page *page;
        long chg;
+       int ret, idx;
+       struct hugetlb_cgroup *h_cg;
 
+       idx = hstate_index(h);
        /*
         * Processes that did not create the mapping will have no
         * reserves and will not have accounted against subpool
@@ -1123,27 +1132,43 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma,
         */
        chg = vma_needs_reservation(h, vma, addr);
        if (chg < 0)
-               return ERR_PTR(-VM_FAULT_OOM);
+               return ERR_PTR(-ENOMEM);
        if (chg)
                if (hugepage_subpool_get_pages(spool, chg))
-                       return ERR_PTR(-VM_FAULT_SIGBUS);
+                       return ERR_PTR(-ENOSPC);
 
+       ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg);
+       if (ret) {
+               hugepage_subpool_put_pages(spool, chg);
+               return ERR_PTR(-ENOSPC);
+       }
        spin_lock(&hugetlb_lock);
        page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve);
-       spin_unlock(&hugetlb_lock);
-
-       if (!page) {
+       if (page) {
+               /* update page cgroup details */
+               hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h),
+                                            h_cg, page);
+               spin_unlock(&hugetlb_lock);
+       } else {
+               spin_unlock(&hugetlb_lock);
                page = alloc_buddy_huge_page(h, NUMA_NO_NODE);
                if (!page) {
+                       hugetlb_cgroup_uncharge_cgroup(idx,
+                                                      pages_per_huge_page(h),
+                                                      h_cg);
                        hugepage_subpool_put_pages(spool, chg);
-                       return ERR_PTR(-VM_FAULT_SIGBUS);
+                       return ERR_PTR(-ENOSPC);
                }
+               spin_lock(&hugetlb_lock);
+               hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h),
+                                            h_cg, page);
+               list_move(&page->lru, &h->hugepage_activelist);
+               spin_unlock(&hugetlb_lock);
        }
 
        set_page_private(page, (unsigned long)spool);
 
        vma_commit_reservation(h, vma, addr);
-
        return page;
 }
 
@@ -1646,7 +1671,7 @@ static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent,
                                    struct attribute_group *hstate_attr_group)
 {
        int retval;
-       int hi = h - hstates;
+       int hi = hstate_index(h);
 
        hstate_kobjs[hi] = kobject_create_and_add(h->name, parent);
        if (!hstate_kobjs[hi])
@@ -1741,11 +1766,13 @@ void hugetlb_unregister_node(struct node *node)
        if (!nhs->hugepages_kobj)
                return;         /* no hstate attributes */
 
-       for_each_hstate(h)
-               if (nhs->hstate_kobjs[h - hstates]) {
-                       kobject_put(nhs->hstate_kobjs[h - hstates]);
-                       nhs->hstate_kobjs[h - hstates] = NULL;
+       for_each_hstate(h) {
+               int idx = hstate_index(h);
+               if (nhs->hstate_kobjs[idx]) {
+                       kobject_put(nhs->hstate_kobjs[idx]);
+                       nhs->hstate_kobjs[idx] = NULL;
                }
+       }
 
        kobject_put(nhs->hugepages_kobj);
        nhs->hugepages_kobj = NULL;
@@ -1848,7 +1875,7 @@ static void __exit hugetlb_exit(void)
        hugetlb_unregister_all_nodes();
 
        for_each_hstate(h) {
-               kobject_put(hstate_kobjs[h - hstates]);
+               kobject_put(hstate_kobjs[hstate_index(h)]);
        }
 
        kobject_put(hugepages_kobj);
@@ -1869,7 +1896,7 @@ static int __init hugetlb_init(void)
                if (!size_to_hstate(default_hstate_size))
                        hugetlb_add_hstate(HUGETLB_PAGE_ORDER);
        }
-       default_hstate_idx = size_to_hstate(default_hstate_size) - hstates;
+       default_hstate_idx = hstate_index(size_to_hstate(default_hstate_size));
        if (default_hstate_max_huge_pages)
                default_hstate.max_huge_pages = default_hstate_max_huge_pages;
 
@@ -1897,19 +1924,27 @@ void __init hugetlb_add_hstate(unsigned order)
                printk(KERN_WARNING "hugepagesz= specified twice, ignoring\n");
                return;
        }
-       BUG_ON(max_hstate >= HUGE_MAX_HSTATE);
+       BUG_ON(hugetlb_max_hstate >= HUGE_MAX_HSTATE);
        BUG_ON(order == 0);
-       h = &hstates[max_hstate++];
+       h = &hstates[hugetlb_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]);
+       INIT_LIST_HEAD(&h->hugepage_activelist);
        h->next_nid_to_alloc = first_node(node_states[N_HIGH_MEMORY]);
        h->next_nid_to_free = first_node(node_states[N_HIGH_MEMORY]);
        snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB",
                                        huge_page_size(h)/1024);
+       /*
+        * Add cgroup control files only if the huge page consists
+        * of more than two normal pages. This is because we use
+        * page[2].lru.next for storing cgoup details.
+        */
+       if (order >= HUGETLB_CGROUP_MIN_ORDER)
+               hugetlb_cgroup_file_init(hugetlb_max_hstate - 1);
 
        parsed_hstate = h;
 }
@@ -1920,10 +1955,10 @@ static int __init hugetlb_nrpages_setup(char *s)
        static unsigned long *last_mhp;
 
        /*
-        * !max_hstate means we haven't parsed a hugepagesz= parameter yet,
+        * !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter yet,
         * so this hugepages= parameter goes to the "default hstate".
         */
-       if (!max_hstate)
+       if (!hugetlb_max_hstate)
                mhp = &default_hstate_max_huge_pages;
        else
                mhp = &parsed_hstate->max_huge_pages;
@@ -1942,7 +1977,7 @@ static int __init hugetlb_nrpages_setup(char *s)
         * But we need to allocate >= MAX_ORDER hstates here early to still
         * use the bootmem allocator.
         */
-       if (max_hstate && parsed_hstate->order >= MAX_ORDER)
+       if (hugetlb_max_hstate && parsed_hstate->order >= MAX_ORDER)
                hugetlb_hstate_alloc_pages(parsed_hstate);
 
        last_mhp = mhp;
@@ -2308,30 +2343,26 @@ static int is_hugetlb_entry_hwpoisoned(pte_t pte)
                return 0;
 }
 
-void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
-                           unsigned long end, struct page *ref_page)
+void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
+                           unsigned long start, unsigned long end,
+                           struct page *ref_page)
 {
+       int force_flush = 0;
        struct mm_struct *mm = vma->vm_mm;
        unsigned long address;
        pte_t *ptep;
        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_mutex. 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 & ~huge_page_mask(h));
        BUG_ON(end & ~huge_page_mask(h));
 
+       tlb_start_vma(tlb, vma);
        mmu_notifier_invalidate_range_start(mm, start, end);
+again:
        spin_lock(&mm->page_table_lock);
        for (address = start; address < end; address += sz) {
                ptep = huge_pte_offset(mm, address);
@@ -2370,30 +2401,64 @@ void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
                }
 
                pte = huge_ptep_get_and_clear(mm, address, ptep);
+               tlb_remove_tlb_entry(tlb, ptep, address);
                if (pte_dirty(pte))
                        set_page_dirty(page);
-               list_add(&page->lru, &page_list);
 
+               page_remove_rmap(page);
+               force_flush = !__tlb_remove_page(tlb, page);
+               if (force_flush)
+                       break;
                /* Bail out after unmapping reference page if supplied */
                if (ref_page)
                        break;
        }
-       flush_tlb_range(vma, start, end);
        spin_unlock(&mm->page_table_lock);
-       mmu_notifier_invalidate_range_end(mm, start, end);
-       list_for_each_entry_safe(page, tmp, &page_list, lru) {
-               page_remove_rmap(page);
-               list_del(&page->lru);
-               put_page(page);
+       /*
+        * mmu_gather ran out of room to batch pages, we break out of
+        * the PTE lock to avoid doing the potential expensive TLB invalidate
+        * and page-free while holding it.
+        */
+       if (force_flush) {
+               force_flush = 0;
+               tlb_flush_mmu(tlb);
+               if (address < end && !ref_page)
+                       goto again;
        }
+       mmu_notifier_invalidate_range_end(mm, start, end);
+       tlb_end_vma(tlb, vma);
+}
+
+void __unmap_hugepage_range_final(struct mmu_gather *tlb,
+                         struct vm_area_struct *vma, unsigned long start,
+                         unsigned long end, struct page *ref_page)
+{
+       __unmap_hugepage_range(tlb, vma, start, end, ref_page);
+
+       /*
+        * Clear this flag so that x86's huge_pmd_share page_table_shareable
+        * test will fail on a vma being torn down, and not grab a page table
+        * on its way out.  We're lucky that the flag has such an appropriate
+        * name, and can in fact be safely cleared here. We could clear it
+        * before the __unmap_hugepage_range above, but all that's necessary
+        * is to clear it before releasing the i_mmap_mutex. This works
+        * because in the context this is called, the VMA is about to be
+        * destroyed and the i_mmap_mutex is held.
+        */
+       vma->vm_flags &= ~VM_MAYSHARE;
 }
 
 void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
                          unsigned long end, struct page *ref_page)
 {
-       mutex_lock(&vma->vm_file->f_mapping->i_mmap_mutex);
-       __unmap_hugepage_range(vma, start, end, ref_page);
-       mutex_unlock(&vma->vm_file->f_mapping->i_mmap_mutex);
+       struct mm_struct *mm;
+       struct mmu_gather tlb;
+
+       mm = vma->vm_mm;
+
+       tlb_gather_mmu(&tlb, mm, 0);
+       __unmap_hugepage_range(&tlb, vma, start, end, ref_page);
+       tlb_finish_mmu(&tlb, start, end);
 }
 
 /*
@@ -2438,9 +2503,8 @@ static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
                 * 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);
+                       unmap_hugepage_range(iter_vma, address,
+                                            address + huge_page_size(h), page);
        }
        mutex_unlock(&mapping->i_mmap_mutex);
 
@@ -2496,6 +2560,7 @@ retry_avoidcopy:
        new_page = alloc_huge_page(vma, address, outside_reserve);
 
        if (IS_ERR(new_page)) {
+               long err = PTR_ERR(new_page);
                page_cache_release(old_page);
 
                /*
@@ -2524,7 +2589,10 @@ retry_avoidcopy:
 
                /* Caller expects lock to be held */
                spin_lock(&mm->page_table_lock);
-               return -PTR_ERR(new_page);
+               if (err == -ENOMEM)
+                       return VM_FAULT_OOM;
+               else
+                       return VM_FAULT_SIGBUS;
        }
 
        /*
@@ -2642,7 +2710,11 @@ retry:
                        goto out;
                page = alloc_huge_page(vma, address, 0);
                if (IS_ERR(page)) {
-                       ret = -PTR_ERR(page);
+                       ret = PTR_ERR(page);
+                       if (ret == -ENOMEM)
+                               ret = VM_FAULT_OOM;
+                       else
+                               ret = VM_FAULT_SIGBUS;
                        goto out;
                }
                clear_huge_page(page, address, pages_per_huge_page(h));
@@ -2679,7 +2751,7 @@ retry:
                 */
                if (unlikely(PageHWPoison(page))) {
                        ret = VM_FAULT_HWPOISON |
-                             VM_FAULT_SET_HINDEX(h - hstates);
+                               VM_FAULT_SET_HINDEX(hstate_index(h));
                        goto backout_unlocked;
                }
        }
@@ -2752,7 +2824,7 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
                        return 0;
                } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry)))
                        return VM_FAULT_HWPOISON_LARGE |
-                              VM_FAULT_SET_HINDEX(h - hstates);
+                               VM_FAULT_SET_HINDEX(hstate_index(h));
        }
 
        ptep = huge_pte_alloc(mm, address, huge_page_size(h));
@@ -2959,9 +3031,14 @@ void hugetlb_change_protection(struct vm_area_struct *vma,
                }
        }
        spin_unlock(&mm->page_table_lock);
-       mutex_unlock(&vma->vm_file->f_mapping->i_mmap_mutex);
-
+       /*
+        * Must flush TLB before releasing i_mmap_mutex: x86's huge_pmd_unshare
+        * may have cleared our pud entry and done put_page on the page table:
+        * once we release i_mmap_mutex, another task can do the final put_page
+        * and that page table be reused and filled with junk.
+        */
        flush_tlb_range(vma, start, end);
+       mutex_unlock(&vma->vm_file->f_mapping->i_mmap_mutex);
 }
 
 int hugetlb_reserve_pages(struct inode *inode,