diff options
Diffstat (limited to 'mm/rmap.c')
| -rw-r--r-- | mm/rmap.c | 148 |
1 files changed, 62 insertions, 86 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index f6838015810f..3ff241f714eb 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -724,7 +724,7 @@ struct page_referenced_arg { /* * arg: page_referenced_arg will be passed */ -static int page_referenced_one(struct page *page, struct vm_area_struct *vma, +static bool page_referenced_one(struct page *page, struct vm_area_struct *vma, unsigned long address, void *arg) { struct page_referenced_arg *pra = arg; @@ -741,7 +741,7 @@ static int page_referenced_one(struct page *page, struct vm_area_struct *vma, if (vma->vm_flags & VM_LOCKED) { page_vma_mapped_walk_done(&pvmw); pra->vm_flags |= VM_LOCKED; - return SWAP_FAIL; /* To break the loop */ + return false; /* To break the loop */ } if (pvmw.pte) { @@ -781,9 +781,9 @@ static int page_referenced_one(struct page *page, struct vm_area_struct *vma, } if (!pra->mapcount) - return SWAP_SUCCESS; /* To break the loop */ + return false; /* To break the loop */ - return SWAP_AGAIN; + return true; } static bool invalid_page_referenced_vma(struct vm_area_struct *vma, void *arg) @@ -812,7 +812,6 @@ int page_referenced(struct page *page, struct mem_cgroup *memcg, unsigned long *vm_flags) { - int ret; int we_locked = 0; struct page_referenced_arg pra = { .mapcount = total_mapcount(page), @@ -846,7 +845,7 @@ int page_referenced(struct page *page, rwc.invalid_vma = invalid_page_referenced_vma; } - ret = rmap_walk(page, &rwc); + rmap_walk(page, &rwc); *vm_flags = pra.vm_flags; if (we_locked) @@ -855,7 +854,7 @@ int page_referenced(struct page *page, return pra.referenced; } -static int page_mkclean_one(struct page *page, struct vm_area_struct *vma, +static bool page_mkclean_one(struct page *page, struct vm_area_struct *vma, unsigned long address, void *arg) { struct page_vma_mapped_walk pvmw = { @@ -908,7 +907,7 @@ static int page_mkclean_one(struct page *page, struct vm_area_struct *vma, } } - return SWAP_AGAIN; + return true; } static bool invalid_mkclean_vma(struct vm_area_struct *vma, void *arg) @@ -1159,7 +1158,7 @@ void page_add_file_rmap(struct page *page, bool compound) goto out; } __mod_node_page_state(page_pgdat(page), NR_FILE_MAPPED, nr); - mem_cgroup_update_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED, nr); + mod_memcg_page_state(page, NR_FILE_MAPPED, nr); out: unlock_page_memcg(page); } @@ -1199,7 +1198,7 @@ static void page_remove_file_rmap(struct page *page, bool compound) * pte lock(a spinlock) is held, which implies preemption disabled. */ __mod_node_page_state(page_pgdat(page), NR_FILE_MAPPED, -nr); - mem_cgroup_update_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED, -nr); + mod_memcg_page_state(page, NR_FILE_MAPPED, -nr); if (unlikely(PageMlocked(page))) clear_page_mlock(page); @@ -1288,15 +1287,10 @@ void page_remove_rmap(struct page *page, bool compound) */ } -struct rmap_private { - enum ttu_flags flags; - int lazyfreed; -}; - /* * @arg: enum ttu_flags will be passed to this argument */ -static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma, +static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma, unsigned long address, void *arg) { struct mm_struct *mm = vma->vm_mm; @@ -1307,13 +1301,12 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma, }; pte_t pteval; struct page *subpage; - int ret = SWAP_AGAIN; - struct rmap_private *rp = arg; - enum ttu_flags flags = rp->flags; + bool ret = true; + enum ttu_flags flags = (enum ttu_flags)arg; /* munlock has nothing to gain from examining un-locked vmas */ if ((flags & TTU_MUNLOCK) && !(vma->vm_flags & VM_LOCKED)) - return SWAP_AGAIN; + return true; if (flags & TTU_SPLIT_HUGE_PMD) { split_huge_pmd_address(vma, address, @@ -1336,7 +1329,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma, */ mlock_vma_page(page); } - ret = SWAP_MLOCK; + ret = false; page_vma_mapped_walk_done(&pvmw); break; } @@ -1354,7 +1347,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma, if (!(flags & TTU_IGNORE_ACCESS)) { if (ptep_clear_flush_young_notify(vma, address, pvmw.pte)) { - ret = SWAP_FAIL; + ret = false; page_vma_mapped_walk_done(&pvmw); break; } @@ -1424,18 +1417,34 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma, * Store the swap location in the pte. * See handle_pte_fault() ... */ - VM_BUG_ON_PAGE(!PageSwapCache(page), page); + if (unlikely(PageSwapBacked(page) != PageSwapCache(page))) { + WARN_ON_ONCE(1); + ret = false; + page_vma_mapped_walk_done(&pvmw); + break; + } + + /* MADV_FREE page check */ + if (!PageSwapBacked(page)) { + if (!PageDirty(page)) { + dec_mm_counter(mm, MM_ANONPAGES); + goto discard; + } - if (!PageDirty(page) && (flags & TTU_LZFREE)) { - /* It's a freeable page by MADV_FREE */ - dec_mm_counter(mm, MM_ANONPAGES); - rp->lazyfreed++; - goto discard; + /* + * If the page was redirtied, it cannot be + * discarded. Remap the page to page table. + */ + set_pte_at(mm, address, pvmw.pte, pteval); + SetPageSwapBacked(page); + ret = false; + page_vma_mapped_walk_done(&pvmw); + break; } if (swap_duplicate(entry) < 0) { set_pte_at(mm, address, pvmw.pte, pteval); - ret = SWAP_FAIL; + ret = false; page_vma_mapped_walk_done(&pvmw); break; } @@ -1492,24 +1501,14 @@ static int page_mapcount_is_zero(struct page *page) * * Tries to remove all the page table entries which are mapping this * page, used in the pageout path. Caller must hold the page lock. - * Return values are: * - * SWAP_SUCCESS - we succeeded in removing all mappings - * SWAP_AGAIN - we missed a mapping, try again later - * SWAP_FAIL - the page is unswappable - * SWAP_MLOCK - page is mlocked. + * If unmap is successful, return true. Otherwise, false. */ -int try_to_unmap(struct page *page, enum ttu_flags flags) +bool try_to_unmap(struct page *page, enum ttu_flags flags) { - int ret; - struct rmap_private rp = { - .flags = flags, - .lazyfreed = 0, - }; - struct rmap_walk_control rwc = { .rmap_one = try_to_unmap_one, - .arg = &rp, + .arg = (void *)flags, .done = page_mapcount_is_zero, .anon_lock = page_lock_anon_vma_read, }; @@ -1526,16 +1525,11 @@ int try_to_unmap(struct page *page, enum ttu_flags flags) rwc.invalid_vma = invalid_migration_vma; if (flags & TTU_RMAP_LOCKED) - ret = rmap_walk_locked(page, &rwc); + rmap_walk_locked(page, &rwc); else - ret = rmap_walk(page, &rwc); + rmap_walk(page, &rwc); - if (ret != SWAP_MLOCK && !page_mapcount(page)) { - ret = SWAP_SUCCESS; - if (rp.lazyfreed && !PageDirty(page)) - ret = SWAP_LZFREE; - } - return ret; + return !page_mapcount(page) ? true : false; } static int page_not_mapped(struct page *page) @@ -1550,34 +1544,22 @@ static int page_not_mapped(struct page *page) * Called from munlock code. Checks all of the VMAs mapping the page * to make sure nobody else has this page mlocked. The page will be * returned with PG_mlocked cleared if no other vmas have it mlocked. - * - * Return values are: - * - * SWAP_AGAIN - no vma is holding page mlocked, or, - * SWAP_AGAIN - page mapped in mlocked vma -- couldn't acquire mmap sem - * SWAP_FAIL - page cannot be located at present - * SWAP_MLOCK - page is now mlocked. */ -int try_to_munlock(struct page *page) -{ - int ret; - struct rmap_private rp = { - .flags = TTU_MUNLOCK, - .lazyfreed = 0, - }; +void try_to_munlock(struct page *page) +{ struct rmap_walk_control rwc = { .rmap_one = try_to_unmap_one, - .arg = &rp, + .arg = (void *)TTU_MUNLOCK, .done = page_not_mapped, .anon_lock = page_lock_anon_vma_read, }; VM_BUG_ON_PAGE(!PageLocked(page) || PageLRU(page), page); + VM_BUG_ON_PAGE(PageCompound(page) && PageDoubleMap(page), page); - ret = rmap_walk(page, &rwc); - return ret; + rmap_walk(page, &rwc); } void __put_anon_vma(struct anon_vma *anon_vma) @@ -1625,13 +1607,12 @@ static struct anon_vma *rmap_walk_anon_lock(struct page *page, * vm_flags for that VMA. That should be OK, because that vma shouldn't be * LOCKED. */ -static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc, +static void rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc, bool locked) { struct anon_vma *anon_vma; pgoff_t pgoff_start, pgoff_end; struct anon_vma_chain *avc; - int ret = SWAP_AGAIN; if (locked) { anon_vma = page_anon_vma(page); @@ -1641,7 +1622,7 @@ static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc, anon_vma = rmap_walk_anon_lock(page, rwc); } if (!anon_vma) - return ret; + return; pgoff_start = page_to_pgoff(page); pgoff_end = pgoff_start + hpage_nr_pages(page) - 1; @@ -1655,8 +1636,7 @@ static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc, if (rwc->invalid_vma && rwc->invalid_vma(vma, rwc->arg)) continue; - ret = rwc->rmap_one(page, vma, address, rwc->arg); - if (ret != SWAP_AGAIN) + if (!rwc->rmap_one(page, vma, address, rwc->arg)) break; if (rwc->done && rwc->done(page)) break; @@ -1664,7 +1644,6 @@ static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc, if (!locked) anon_vma_unlock_read(anon_vma); - return ret; } /* @@ -1680,13 +1659,12 @@ static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc, * vm_flags for that VMA. That should be OK, because that vma shouldn't be * LOCKED. */ -static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc, +static void rmap_walk_file(struct page *page, struct rmap_walk_control *rwc, bool locked) { struct address_space *mapping = page_mapping(page); pgoff_t pgoff_start, pgoff_end; struct vm_area_struct *vma; - int ret = SWAP_AGAIN; /* * The page lock not only makes sure that page->mapping cannot @@ -1697,7 +1675,7 @@ static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc, VM_BUG_ON_PAGE(!PageLocked(page), page); if (!mapping) - return ret; + return; pgoff_start = page_to_pgoff(page); pgoff_end = pgoff_start + hpage_nr_pages(page) - 1; @@ -1712,8 +1690,7 @@ static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc, if (rwc->invalid_vma && rwc->invalid_vma(vma, rwc->arg)) continue; - ret = rwc->rmap_one(page, vma, address, rwc->arg); - if (ret != SWAP_AGAIN) + if (!rwc->rmap_one(page, vma, address, rwc->arg)) goto done; if (rwc->done && rwc->done(page)) goto done; @@ -1722,28 +1699,27 @@ static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc, done: if (!locked) i_mmap_unlock_read(mapping); - return ret; } -int rmap_walk(struct page *page, struct rmap_walk_control *rwc) +void rmap_walk(struct page *page, struct rmap_walk_control *rwc) { if (unlikely(PageKsm(page))) - return rmap_walk_ksm(page, rwc); + rmap_walk_ksm(page, rwc); else if (PageAnon(page)) - return rmap_walk_anon(page, rwc, false); + rmap_walk_anon(page, rwc, false); else - return rmap_walk_file(page, rwc, false); + rmap_walk_file(page, rwc, false); } /* Like rmap_walk, but caller holds relevant rmap lock */ -int rmap_walk_locked(struct page *page, struct rmap_walk_control *rwc) +void rmap_walk_locked(struct page *page, struct rmap_walk_control *rwc) { /* no ksm support for now */ VM_BUG_ON_PAGE(PageKsm(page), page); if (PageAnon(page)) - return rmap_walk_anon(page, rwc, true); + rmap_walk_anon(page, rwc, true); else - return rmap_walk_file(page, rwc, true); + rmap_walk_file(page, rwc, true); } #ifdef CONFIG_HUGETLB_PAGE |