X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=mm%2Frmap.c;h=df2c41c2a9a2c1ac4d46b67c424a0001122a57ea;hb=fab8d6ddf6dee2608869005d45fe97f70e4f5bdd;hp=4107f64ff749e53d7b9ba0eec72e0dfa4862f9aa;hpb=9617d95e6e9ffd883cf90a89724fe60d7ab22f9a;p=linux-2.6 diff --git a/mm/rmap.c b/mm/rmap.c index 4107f64ff7..df2c41c2a9 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -20,20 +20,20 @@ /* * Lock ordering in mm: * - * inode->i_sem (while writing or truncating, not reading or faulting) + * inode->i_mutex (while writing or truncating, not reading or faulting) * inode->i_alloc_sem * * When a page fault occurs in writing from user to file, down_read - * of mmap_sem nests within i_sem; in sys_msync, i_sem nests within - * down_read of mmap_sem; i_sem and down_write of mmap_sem are never - * taken together; in truncation, i_sem is taken outermost. + * of mmap_sem nests within i_mutex; in sys_msync, i_mutex nests within + * down_read of mmap_sem; i_mutex and down_write of mmap_sem are never + * taken together; in truncation, i_mutex is taken outermost. * * mm->mmap_sem * page->flags PG_locked (lock_page) * mapping->i_mmap_lock * anon_vma->lock * mm->page_table_lock or pte_lock - * zone->lru_lock (in mark_page_accessed) + * zone->lru_lock (in mark_page_accessed, isolate_lru_page) * swap_lock (in swap_duplicate, swap_info_get) * mmlist_lock (in mmput, drain_mmlist and others) * mapping->private_lock (in __set_page_dirty_buffers) @@ -52,6 +52,7 @@ #include #include #include +#include #include @@ -205,6 +206,36 @@ out: return anon_vma; } +#ifdef CONFIG_MIGRATION +/* + * Remove an anonymous page from swap replacing the swap pte's + * through real pte's pointing to valid pages and then releasing + * the page from the swap cache. + * + * Must hold page lock on page. + */ +void remove_from_swap(struct page *page) +{ + struct anon_vma *anon_vma; + struct vm_area_struct *vma; + + if (!PageAnon(page) || !PageSwapCache(page)) + return; + + anon_vma = page_lock_anon_vma(page); + if (!anon_vma) + return; + + list_for_each_entry(vma, &anon_vma->head, anon_vma_node) + remove_vma_swap(vma, page); + + spin_unlock(&anon_vma->lock); + + delete_from_swap_cache(page); +} +EXPORT_SYMBOL(remove_from_swap); +#endif + /* * At what user virtual address is page expected in vma? */ @@ -451,7 +482,11 @@ static void __page_set_anon_rmap(struct page *page, page->index = linear_page_index(vma, address); - inc_page_state(nr_mapped); + /* + * nr_mapped state can be updated without turning off + * interrupts because it is not modified via interrupt. + */ + __inc_page_state(nr_mapped); } /** @@ -498,7 +533,7 @@ void page_add_file_rmap(struct page *page) BUG_ON(!pfn_valid(page_to_pfn(page))); if (atomic_inc_and_test(&page->_mapcount)) - inc_page_state(nr_mapped); + __inc_page_state(nr_mapped); } /** @@ -510,6 +545,13 @@ void page_add_file_rmap(struct page *page) void page_remove_rmap(struct page *page) { if (atomic_add_negative(-1, &page->_mapcount)) { + if (page_mapcount(page) < 0) { + printk (KERN_EMERG "Eeek! page_mapcount(page) went negative! (%d)\n", page_mapcount(page)); + printk (KERN_EMERG " page->flags = %lx\n", page->flags); + printk (KERN_EMERG " page->count = %x\n", page_count(page)); + printk (KERN_EMERG " page->mapping = %p\n", page->mapping); + } + BUG_ON(page_mapcount(page) < 0); /* * It would be tidy to reset the PageAnon mapping here, @@ -522,7 +564,7 @@ void page_remove_rmap(struct page *page) */ if (page_test_and_clear_dirty(page)) set_page_dirty(page); - dec_page_state(nr_mapped); + __dec_page_state(nr_mapped); } } @@ -530,7 +572,8 @@ void page_remove_rmap(struct page *page) * Subfunctions of try_to_unmap: try_to_unmap_one called * repeatedly from either try_to_unmap_anon or try_to_unmap_file. */ -static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma) +static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma, + int ignore_refs) { struct mm_struct *mm = vma->vm_mm; unsigned long address; @@ -553,7 +596,8 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma) * skipped over this mm) then we should reactivate it. */ if ((vma->vm_flags & VM_LOCKED) || - ptep_clear_flush_young(vma, address, pte)) { + (ptep_clear_flush_young(vma, address, pte) + && !ignore_refs)) { ret = SWAP_FAIL; goto out_unmap; } @@ -687,7 +731,7 @@ static void try_to_unmap_cluster(unsigned long cursor, pte_unmap_unlock(pte - 1, ptl); } -static int try_to_unmap_anon(struct page *page) +static int try_to_unmap_anon(struct page *page, int ignore_refs) { struct anon_vma *anon_vma; struct vm_area_struct *vma; @@ -698,7 +742,7 @@ static int try_to_unmap_anon(struct page *page) return ret; list_for_each_entry(vma, &anon_vma->head, anon_vma_node) { - ret = try_to_unmap_one(page, vma); + ret = try_to_unmap_one(page, vma, ignore_refs); if (ret == SWAP_FAIL || !page_mapped(page)) break; } @@ -715,7 +759,7 @@ static int try_to_unmap_anon(struct page *page) * * This function is only called from try_to_unmap for object-based pages. */ -static int try_to_unmap_file(struct page *page) +static int try_to_unmap_file(struct page *page, int ignore_refs) { struct address_space *mapping = page->mapping; pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); @@ -729,7 +773,7 @@ static int try_to_unmap_file(struct page *page) spin_lock(&mapping->i_mmap_lock); vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) { - ret = try_to_unmap_one(page, vma); + ret = try_to_unmap_one(page, vma, ignore_refs); if (ret == SWAP_FAIL || !page_mapped(page)) goto out; } @@ -814,16 +858,16 @@ out: * SWAP_AGAIN - we missed a mapping, try again later * SWAP_FAIL - the page is unswappable */ -int try_to_unmap(struct page *page) +int try_to_unmap(struct page *page, int ignore_refs) { int ret; BUG_ON(!PageLocked(page)); if (PageAnon(page)) - ret = try_to_unmap_anon(page); + ret = try_to_unmap_anon(page, ignore_refs); else - ret = try_to_unmap_file(page); + ret = try_to_unmap_file(page, ignore_refs); if (!page_mapped(page)) ret = SWAP_SUCCESS;