[PATCH] m68k: convert thread flags to use bit fields
[safe/jmp/linux-2.6] / mm / memory.c
index 8461e2d..2998cfc 100644 (file)
@@ -114,6 +114,7 @@ static void free_pte_range(struct mmu_gather *tlb, pmd_t *pmd)
 {
        struct page *page = pmd_page(*pmd);
        pmd_clear(pmd);
+       pte_lock_deinit(page);
        pte_free_tlb(tlb, page);
        dec_page_state(nr_page_table_pages);
        tlb->mm->nr_ptes--;
@@ -294,10 +295,12 @@ int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address)
        if (!new)
                return -ENOMEM;
 
+       pte_lock_init(new);
        spin_lock(&mm->page_table_lock);
-       if (pmd_present(*pmd))          /* Another has populated it */
+       if (pmd_present(*pmd)) {        /* Another has populated it */
+               pte_lock_deinit(new);
                pte_free(new);
-       else {
+       else {
                mm->nr_ptes++;
                inc_page_state(nr_page_table_pages);
                pmd_populate(mm, pmd, new);
@@ -369,7 +372,9 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
                        /* make sure dst_mm is on swapoff's mmlist. */
                        if (unlikely(list_empty(&dst_mm->mmlist))) {
                                spin_lock(&mmlist_lock);
-                               list_add(&dst_mm->mmlist, &src_mm->mmlist);
+                               if (list_empty(&dst_mm->mmlist))
+                                       list_add(&dst_mm->mmlist,
+                                                &src_mm->mmlist);
                                spin_unlock(&mmlist_lock);
                        }
                }
@@ -432,7 +437,7 @@ again:
        if (!dst_pte)
                return -ENOMEM;
        src_pte = pte_offset_map_nested(src_pmd, addr);
-       src_ptl = &src_mm->page_table_lock;
+       src_ptl = pte_lockptr(src_mm, src_pmd);
        spin_lock(src_ptl);
 
        do {
@@ -544,10 +549,10 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
        return 0;
 }
 
-static void zap_pte_range(struct mmu_gather *tlb,
+static unsigned long zap_pte_range(struct mmu_gather *tlb,
                                struct vm_area_struct *vma, pmd_t *pmd,
                                unsigned long addr, unsigned long end,
-                               struct zap_details *details)
+                               long *zap_work, struct zap_details *details)
 {
        struct mm_struct *mm = tlb->mm;
        pte_t *pte;
@@ -558,10 +563,15 @@ static void zap_pte_range(struct mmu_gather *tlb,
        pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
        do {
                pte_t ptent = *pte;
-               if (pte_none(ptent))
+               if (pte_none(ptent)) {
+                       (*zap_work)--;
                        continue;
+               }
                if (pte_present(ptent)) {
                        struct page *page = NULL;
+
+                       (*zap_work) -= PAGE_SIZE;
+
                        if (!(vma->vm_flags & VM_RESERVED)) {
                                unsigned long pfn = pte_pfn(ptent);
                                if (unlikely(!pfn_valid(pfn)))
@@ -619,16 +629,18 @@ static void zap_pte_range(struct mmu_gather *tlb,
                if (!pte_file(ptent))
                        free_swap_and_cache(pte_to_swp_entry(ptent));
                pte_clear_full(mm, addr, pte, tlb->fullmm);
-       } while (pte++, addr += PAGE_SIZE, addr != end);
+       } while (pte++, addr += PAGE_SIZE, (addr != end && *zap_work > 0));
 
        add_mm_rss(mm, file_rss, anon_rss);
        pte_unmap_unlock(pte - 1, ptl);
+
+       return addr;
 }
 
-static inline void zap_pmd_range(struct mmu_gather *tlb,
+static inline unsigned long zap_pmd_range(struct mmu_gather *tlb,
                                struct vm_area_struct *vma, pud_t *pud,
                                unsigned long addr, unsigned long end,
-                               struct zap_details *details)
+                               long *zap_work, struct zap_details *details)
 {
        pmd_t *pmd;
        unsigned long next;
@@ -636,16 +648,21 @@ static inline void zap_pmd_range(struct mmu_gather *tlb,
        pmd = pmd_offset(pud, addr);
        do {
                next = pmd_addr_end(addr, end);
-               if (pmd_none_or_clear_bad(pmd))
+               if (pmd_none_or_clear_bad(pmd)) {
+                       (*zap_work)--;
                        continue;
-               zap_pte_range(tlb, vma, pmd, addr, next, details);
-       } while (pmd++, addr = next, addr != end);
+               }
+               next = zap_pte_range(tlb, vma, pmd, addr, next,
+                                               zap_work, details);
+       } while (pmd++, addr = next, (addr != end && *zap_work > 0));
+
+       return addr;
 }
 
-static inline void zap_pud_range(struct mmu_gather *tlb,
+static inline unsigned long zap_pud_range(struct mmu_gather *tlb,
                                struct vm_area_struct *vma, pgd_t *pgd,
                                unsigned long addr, unsigned long end,
-                               struct zap_details *details)
+                               long *zap_work, struct zap_details *details)
 {
        pud_t *pud;
        unsigned long next;
@@ -653,15 +670,21 @@ static inline void zap_pud_range(struct mmu_gather *tlb,
        pud = pud_offset(pgd, addr);
        do {
                next = pud_addr_end(addr, end);
-               if (pud_none_or_clear_bad(pud))
+               if (pud_none_or_clear_bad(pud)) {
+                       (*zap_work)--;
                        continue;
-               zap_pmd_range(tlb, vma, pud, addr, next, details);
-       } while (pud++, addr = next, addr != end);
+               }
+               next = zap_pmd_range(tlb, vma, pud, addr, next,
+                                               zap_work, details);
+       } while (pud++, addr = next, (addr != end && *zap_work > 0));
+
+       return addr;
 }
 
-static void unmap_page_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
+static unsigned long unmap_page_range(struct mmu_gather *tlb,
+                               struct vm_area_struct *vma,
                                unsigned long addr, unsigned long end,
-                               struct zap_details *details)
+                               long *zap_work, struct zap_details *details)
 {
        pgd_t *pgd;
        unsigned long next;
@@ -674,11 +697,16 @@ static void unmap_page_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
        pgd = pgd_offset(vma->vm_mm, addr);
        do {
                next = pgd_addr_end(addr, end);
-               if (pgd_none_or_clear_bad(pgd))
+               if (pgd_none_or_clear_bad(pgd)) {
+                       (*zap_work)--;
                        continue;
-               zap_pud_range(tlb, vma, pgd, addr, next, details);
-       } while (pgd++, addr = next, addr != end);
+               }
+               next = zap_pud_range(tlb, vma, pgd, addr, next,
+                                               zap_work, details);
+       } while (pgd++, addr = next, (addr != end && *zap_work > 0));
        tlb_end_vma(tlb, vma);
+
+       return addr;
 }
 
 #ifdef CONFIG_PREEMPT
@@ -719,7 +747,7 @@ unsigned long unmap_vmas(struct mmu_gather **tlbp,
                unsigned long end_addr, unsigned long *nr_accounted,
                struct zap_details *details)
 {
-       unsigned long zap_bytes = ZAP_BLOCK_SIZE;
+       long zap_work = ZAP_BLOCK_SIZE;
        unsigned long tlb_start = 0;    /* For tlb_finish_mmu */
        int tlb_start_valid = 0;
        unsigned long start = start_addr;
@@ -740,27 +768,25 @@ unsigned long unmap_vmas(struct mmu_gather **tlbp,
                        *nr_accounted += (end - start) >> PAGE_SHIFT;
 
                while (start != end) {
-                       unsigned long block;
-
                        if (!tlb_start_valid) {
                                tlb_start = start;
                                tlb_start_valid = 1;
                        }
 
-                       if (is_vm_hugetlb_page(vma)) {
-                               block = end - start;
+                       if (unlikely(is_vm_hugetlb_page(vma))) {
                                unmap_hugepage_range(vma, start, end);
-                       } else {
-                               block = min(zap_bytes, end - start);
-                               unmap_page_range(*tlbp, vma, start,
-                                               start + block, details);
+                               zap_work -= (end - start) /
+                                               (HPAGE_SIZE / PAGE_SIZE);
+                               start = end;
+                       } else
+                               start = unmap_page_range(*tlbp, vma,
+                                               start, end, &zap_work, details);
+
+                       if (zap_work > 0) {
+                               BUG_ON(start != end);
+                               break;
                        }
 
-                       start += block;
-                       zap_bytes -= block;
-                       if ((long)zap_bytes > 0)
-                               continue;
-
                        tlb_finish_mmu(*tlbp, tlb_start, start);
 
                        if (need_resched() ||
@@ -774,7 +800,7 @@ unsigned long unmap_vmas(struct mmu_gather **tlbp,
 
                        *tlbp = tlb_gather_mmu(vma->vm_mm, fullmm);
                        tlb_start_valid = 0;
-                       zap_bytes = ZAP_BLOCK_SIZE;
+                       zap_work = ZAP_BLOCK_SIZE;
                }
        }
 out:
@@ -1194,15 +1220,16 @@ EXPORT_SYMBOL(remap_pfn_range);
  * (but do_wp_page is only called after already making such a check;
  * and do_anonymous_page and do_no_page can safely check later on).
  */
-static inline int pte_unmap_same(struct mm_struct *mm,
+static inline int pte_unmap_same(struct mm_struct *mm, pmd_t *pmd,
                                pte_t *page_table, pte_t orig_pte)
 {
        int same = 1;
 #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)
        if (sizeof(pte_t) > sizeof(unsigned long)) {
-               spin_lock(&mm->page_table_lock);
+               spinlock_t *ptl = pte_lockptr(mm, pmd);
+               spin_lock(ptl);
                same = pte_same(*page_table, orig_pte);
-               spin_unlock(&mm->page_table_lock);
+               spin_unlock(ptl);
        }
 #endif
        pte_unmap(page_table);
@@ -1655,7 +1682,7 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
        pte_t pte;
        int ret = VM_FAULT_MINOR;
 
-       if (!pte_unmap_same(mm, page_table, orig_pte))
+       if (!pte_unmap_same(mm, pmd, page_table, orig_pte))
                goto out;
 
        entry = pte_to_swp_entry(orig_pte);
@@ -1773,7 +1800,7 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
                page_cache_get(page);
                entry = mk_pte(page, vma->vm_page_prot);
 
-               ptl = &mm->page_table_lock;
+               ptl = pte_lockptr(mm, pmd);
                spin_lock(ptl);
                if (!pte_none(*page_table))
                        goto release;
@@ -1934,7 +1961,7 @@ static int do_file_page(struct mm_struct *mm, struct vm_area_struct *vma,
        pgoff_t pgoff;
        int err;
 
-       if (!pte_unmap_same(mm, page_table, orig_pte))
+       if (!pte_unmap_same(mm, pmd, page_table, orig_pte))
                return VM_FAULT_MINOR;
 
        if (unlikely(!(vma->vm_flags & VM_NONLINEAR))) {
@@ -1974,9 +2001,10 @@ static inline int handle_pte_fault(struct mm_struct *mm,
                pte_t *pte, pmd_t *pmd, int write_access)
 {
        pte_t entry;
+       pte_t old_entry;
        spinlock_t *ptl;
 
-       entry = *pte;
+       old_entry = entry = *pte;
        if (!pte_present(entry)) {
                if (pte_none(entry)) {
                        if (!vma->vm_ops || !vma->vm_ops->nopage)
@@ -1992,7 +2020,7 @@ static inline int handle_pte_fault(struct mm_struct *mm,
                                        pte, pmd, write_access, entry);
        }
 
-       ptl = &mm->page_table_lock;
+       ptl = pte_lockptr(mm, pmd);
        spin_lock(ptl);
        if (unlikely(!pte_same(*pte, entry)))
                goto unlock;
@@ -2003,9 +2031,20 @@ static inline int handle_pte_fault(struct mm_struct *mm,
                entry = pte_mkdirty(entry);
        }
        entry = pte_mkyoung(entry);
-       ptep_set_access_flags(vma, address, pte, entry, write_access);
-       update_mmu_cache(vma, address, entry);
-       lazy_mmu_prot_update(entry);
+       if (!pte_same(old_entry, entry)) {
+               ptep_set_access_flags(vma, address, pte, entry, write_access);
+               update_mmu_cache(vma, address, entry);
+               lazy_mmu_prot_update(entry);
+       } else {
+               /*
+                * This is needed only for protection faults but the arch code
+                * is not yet telling us if this is a protection fault or not.
+                * This still avoids useless tlb flushes for .text page faults
+                * with threads.
+                */
+               if (write_access)
+                       flush_tlb_page(vma, address);
+       }
 unlock:
        pte_unmap_unlock(pte, ptl);
        return VM_FAULT_MINOR;