X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=mm%2Frmap.c;h=0383acfcb0681a877f15f59d4d712980c37e1811;hb=8e6c81fe289e90b188203ec1db1dc2f3e992ebde;hp=39ae5a9bf382615120e14e3fbe4efd3bc7cda153;hpb=375614422509c98a1f3dbef410206bf81775169b;p=linux-2.6-omap-h63xx.git diff --git a/mm/rmap.c b/mm/rmap.c index 39ae5a9bf38..0383acfcb06 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -49,6 +49,7 @@ #include #include #include +#include #include @@ -223,10 +224,14 @@ unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma) /* * Check that @page is mapped at @address into @mm. * + * If @sync is false, page_check_address may perform a racy check to avoid + * the page table lock when the pte is not present (helpful when reclaiming + * highly shared pages). + * * On success returns with pte mapped and locked. */ pte_t *page_check_address(struct page *page, struct mm_struct *mm, - unsigned long address, spinlock_t **ptlp) + unsigned long address, spinlock_t **ptlp, int sync) { pgd_t *pgd; pud_t *pud; @@ -248,7 +253,7 @@ pte_t *page_check_address(struct page *page, struct mm_struct *mm, pte = pte_offset_map(pmd, address); /* Make a quick check before getting the lock */ - if (!pte_present(*pte)) { + if (!sync && !pte_present(*pte)) { pte_unmap(pte); return NULL; } @@ -280,14 +285,14 @@ static int page_referenced_one(struct page *page, if (address == -EFAULT) goto out; - pte = page_check_address(page, mm, address, &ptl); + pte = page_check_address(page, mm, address, &ptl, 0); if (!pte) goto out; if (vma->vm_flags & VM_LOCKED) { referenced++; *mapcount = 1; /* break early from loop */ - } else if (ptep_clear_flush_young(vma, address, pte)) + } else if (ptep_clear_flush_young_notify(vma, address, pte)) referenced++; /* Pretend the page is referenced if the task has the @@ -421,7 +426,7 @@ int page_referenced(struct page *page, int is_locked, referenced += page_referenced_anon(page, mem_cont); else if (is_locked) referenced += page_referenced_file(page, mem_cont); - else if (TestSetPageLocked(page)) + else if (!trylock_page(page)) referenced++; else { if (page->mapping) @@ -449,7 +454,7 @@ static int page_mkclean_one(struct page *page, struct vm_area_struct *vma) if (address == -EFAULT) goto out; - pte = page_check_address(page, mm, address, &ptl); + pte = page_check_address(page, mm, address, &ptl, 1); if (!pte) goto out; @@ -457,7 +462,7 @@ static int page_mkclean_one(struct page *page, struct vm_area_struct *vma) pte_t entry; flush_cache_page(vma, address, pte_pfn(*pte)); - entry = ptep_clear_flush(vma, address, pte); + entry = ptep_clear_flush_notify(vma, address, pte); entry = pte_wrprotect(entry); entry = pte_mkclean(entry); set_pte_at(mm, address, pte, entry); @@ -657,6 +662,22 @@ void page_remove_rmap(struct page *page, struct vm_area_struct *vma) BUG(); } + /* + * Now that the last pte has gone, s390 must transfer dirty + * flag from storage key to struct page. We can usually skip + * this if the page is anon, so about to be freed; but perhaps + * not if it's in swapcache - there might be another pte slot + * containing the swap entry, but page not yet written to swap. + */ + if ((!PageAnon(page) || PageSwapCache(page)) && + page_test_dirty(page)) { + page_clear_dirty(page); + set_page_dirty(page); + } + + mem_cgroup_uncharge_page(page); + __dec_zone_page_state(page, + PageAnon(page) ? NR_ANON_PAGES : NR_FILE_MAPPED); /* * It would be tidy to reset the PageAnon mapping here, * but that might overwrite a racing page_add_anon_rmap @@ -666,14 +687,6 @@ void page_remove_rmap(struct page *page, struct vm_area_struct *vma) * Leaving it set also helps swapoff to reinstate ptes * faster for those pages still in swapcache. */ - if (page_test_dirty(page)) { - page_clear_dirty(page); - set_page_dirty(page); - } - mem_cgroup_uncharge_page(page); - - __dec_zone_page_state(page, - PageAnon(page) ? NR_ANON_PAGES : NR_FILE_MAPPED); } } @@ -695,7 +708,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma, if (address == -EFAULT) goto out; - pte = page_check_address(page, mm, address, &ptl); + pte = page_check_address(page, mm, address, &ptl, 0); if (!pte) goto out; @@ -705,14 +718,14 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma, * skipped over this mm) then we should reactivate it. */ if (!migration && ((vma->vm_flags & VM_LOCKED) || - (ptep_clear_flush_young(vma, address, pte)))) { + (ptep_clear_flush_young_notify(vma, address, pte)))) { ret = SWAP_FAIL; goto out_unmap; } /* Nuke the page table entry. */ flush_cache_page(vma, address, page_to_pfn(page)); - pteval = ptep_clear_flush(vma, address, pte); + pteval = ptep_clear_flush_notify(vma, address, pte); /* Move the dirty bit to the physical page now the pte is gone. */ if (pte_dirty(pteval)) @@ -837,12 +850,12 @@ static void try_to_unmap_cluster(unsigned long cursor, page = vm_normal_page(vma, address, *pte); BUG_ON(!page || PageAnon(page)); - if (ptep_clear_flush_young(vma, address, pte)) + if (ptep_clear_flush_young_notify(vma, address, pte)) continue; /* Nuke the page table entry. */ flush_cache_page(vma, address, pte_pfn(*pte)); - pteval = ptep_clear_flush(vma, address, pte); + pteval = ptep_clear_flush_notify(vma, address, pte); /* If nonlinear, store the file page offset in the pte. */ if (page->index != linear_page_index(vma, address))