diff options
Diffstat (limited to 'mm/mmap.c')
| -rw-r--r-- | mm/mmap.c | 102 |
1 files changed, 21 insertions, 81 deletions
@@ -29,6 +29,10 @@ #include <asm/cacheflush.h> #include <asm/tlb.h> +static void unmap_region(struct mm_struct *mm, + struct vm_area_struct *vma, struct vm_area_struct *prev, + unsigned long start, unsigned long end); + /* * WARNING: the debugging will use recursive algorithms so never enable this * unless you know what you are doing. @@ -1129,7 +1133,8 @@ unmap_and_free_vma: fput(file); /* Undo any partial mapping done by a device driver. */ - zap_page_range(vma, vma->vm_start, vma->vm_end - vma->vm_start, NULL); + unmap_region(mm, vma, prev, vma->vm_start, vma->vm_end); + charged = 0; free_vma: kmem_cache_free(vm_area_cachep, vma); unacct_error: @@ -1572,66 +1577,6 @@ find_extend_vma(struct mm_struct * mm, unsigned long addr) } #endif -/* - * Try to free as many page directory entries as we can, - * without having to work very hard at actually scanning - * the page tables themselves. - * - * Right now we try to free page tables if we have a nice - * PGDIR-aligned area that got free'd up. We could be more - * granular if we want to, but this is fast and simple, - * and covers the bad cases. - * - * "prev", if it exists, points to a vma before the one - * we just free'd - but there's no telling how much before. - */ -static void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *prev, - unsigned long start, unsigned long end) -{ - unsigned long first = start & PGDIR_MASK; - unsigned long last = end + PGDIR_SIZE - 1; - struct mm_struct *mm = tlb->mm; - - if (last > MM_VM_SIZE(mm) || last < end) - last = MM_VM_SIZE(mm); - - if (!prev) { - prev = mm->mmap; - if (!prev) - goto no_mmaps; - if (prev->vm_end > start) { - if (last > prev->vm_start) - last = prev->vm_start; - goto no_mmaps; - } - } - for (;;) { - struct vm_area_struct *next = prev->vm_next; - - if (next) { - if (next->vm_start < start) { - prev = next; - continue; - } - if (last > next->vm_start) - last = next->vm_start; - } - if (prev->vm_end > first) - first = prev->vm_end; - break; - } -no_mmaps: - if (last < first) /* for arches with discontiguous pgd indices */ - return; - if (first < FIRST_USER_PGD_NR * PGDIR_SIZE) - first = FIRST_USER_PGD_NR * PGDIR_SIZE; - /* No point trying to free anything if we're in the same pte page */ - if ((first & PMD_MASK) < (last & PMD_MASK)) { - clear_page_range(tlb, first, last); - flush_tlb_pgtables(mm, first, last); - } -} - /* Normal function to fix up a mapping * This function is the default for when an area has no specific * function. This may be used as part of a more specific routine. @@ -1674,24 +1619,22 @@ static void unmap_vma_list(struct mm_struct *mm, * Called with the page table lock held. */ static void unmap_region(struct mm_struct *mm, - struct vm_area_struct *vma, - struct vm_area_struct *prev, - unsigned long start, - unsigned long end) + struct vm_area_struct *vma, struct vm_area_struct *prev, + unsigned long start, unsigned long end) { + struct vm_area_struct *next = prev? prev->vm_next: mm->mmap; struct mmu_gather *tlb; unsigned long nr_accounted = 0; lru_add_drain(); + spin_lock(&mm->page_table_lock); tlb = tlb_gather_mmu(mm, 0); unmap_vmas(&tlb, mm, vma, start, end, &nr_accounted, NULL); vm_unacct_memory(nr_accounted); - - if (is_hugepage_only_range(mm, start, end - start)) - hugetlb_free_pgtables(tlb, prev, start, end); - else - free_pgtables(tlb, prev, start, end); + free_pgtables(&tlb, vma, prev? prev->vm_end: 0, + next? next->vm_start: 0); tlb_finish_mmu(tlb, start, end); + spin_unlock(&mm->page_table_lock); } /* @@ -1823,9 +1766,7 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len) * Remove the vma's, and unmap the actual pages */ detach_vmas_to_be_unmapped(mm, mpnt, prev, end); - spin_lock(&mm->page_table_lock); unmap_region(mm, mpnt, prev, start, end); - spin_unlock(&mm->page_table_lock); /* Fix up all other VM information */ unmap_vma_list(mm, mpnt); @@ -1957,25 +1898,21 @@ EXPORT_SYMBOL(do_brk); void exit_mmap(struct mm_struct *mm) { struct mmu_gather *tlb; - struct vm_area_struct *vma; + struct vm_area_struct *vma = mm->mmap; unsigned long nr_accounted = 0; lru_add_drain(); spin_lock(&mm->page_table_lock); - tlb = tlb_gather_mmu(mm, 1); flush_cache_mm(mm); - /* Use ~0UL here to ensure all VMAs in the mm are unmapped */ - mm->map_count -= unmap_vmas(&tlb, mm, mm->mmap, 0, - ~0UL, &nr_accounted, NULL); + tlb = tlb_gather_mmu(mm, 1); + /* Use -1 here to ensure all VMAs in the mm are unmapped */ + mm->map_count -= unmap_vmas(&tlb, mm, vma, 0, -1, &nr_accounted, NULL); vm_unacct_memory(nr_accounted); - BUG_ON(mm->map_count); /* This is just debugging */ - clear_page_range(tlb, FIRST_USER_PGD_NR * PGDIR_SIZE, MM_VM_SIZE(mm)); - + free_pgtables(&tlb, vma, 0, 0); tlb_finish_mmu(tlb, 0, MM_VM_SIZE(mm)); - vma = mm->mmap; mm->mmap = mm->mmap_cache = NULL; mm->mm_rb = RB_ROOT; set_mm_counter(mm, rss, 0); @@ -1993,6 +1930,9 @@ void exit_mmap(struct mm_struct *mm) remove_vm_struct(vma); vma = next; } + + BUG_ON(mm->map_count); /* This is just debugging */ + BUG_ON(mm->nr_ptes); /* This is just debugging */ } /* Insert vm structure into process list sorted by address |
