Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933273AbcCKXCv (ORCPT ); Fri, 11 Mar 2016 18:02:51 -0500 Received: from mga03.intel.com ([134.134.136.65]:59008 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932872AbcCKW7k (ORCPT ); Fri, 11 Mar 2016 17:59:40 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,321,1455004800"; d="scan'208";a="762612812" From: "Kirill A. Shutemov" To: Hugh Dickins , Andrea Arcangeli , Andrew Morton Cc: Dave Hansen , Vlastimil Babka , Christoph Lameter , Naoya Horiguchi , Jerome Marchand , Yang Shi , Sasha Levin , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCHv4 24/25] shmem: add huge pages support Date: Sat, 12 Mar 2016 01:59:16 +0300 Message-Id: <1457737157-38573-25-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1457737157-38573-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1457737157-38573-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 19003 Lines: 645 Here's basic implementation of huge pages support for shmem/tmpfs. It's all pretty streight-forward: - shmem_getpage() allcoates huge page if it can and try to inserd into radix tree with shmem_add_to_page_cache(); - shmem_add_to_page_cache() puts the page onto radix-tree if there's space for it; - shmem_undo_range() removes huge pages, if it fully within range. Partial truncate of huge pages zero out this part of THP. This have visible effect on fallocate(FALLOC_FL_PUNCH_HOLE) behaviour. As we don't really create hole in this case, lseek(SEEK_HOLE) may have inconsistent results depending what pages happened to be allocated. - no need to change shmem_fault: core-mm will map an compound page as huge if VMA is suitable; Signed-off-by: Kirill A. Shutemov --- include/linux/huge_mm.h | 2 + mm/memory.c | 5 +- mm/mempolicy.c | 2 +- mm/page-writeback.c | 1 + mm/shmem.c | 355 +++++++++++++++++++++++++++++++++++++----------- mm/swap.c | 2 + 6 files changed, 282 insertions(+), 85 deletions(-) diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index d40eab8c9d00..2696a61d1bdc 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -160,6 +160,8 @@ struct page *get_huge_zero_page(void); #define transparent_hugepage_enabled(__vma) 0 +static inline void prep_transhuge_page(struct page *page) {} + #define transparent_hugepage_flags 0UL static inline int split_huge_page_to_list(struct page *page, struct list_head *list) diff --git a/mm/memory.c b/mm/memory.c index c0a2510b9e15..939499dbdff5 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1090,7 +1090,7 @@ again: * unmap shared but keep private pages. */ if (details->check_mapping && - details->check_mapping != page->mapping) + details->check_mapping != page_rmapping(page)) continue; } ptent = ptep_get_and_clear_full(mm, addr, pte, @@ -1181,7 +1181,8 @@ static inline unsigned long zap_pmd_range(struct mmu_gather *tlb, next = pmd_addr_end(addr, end); if (pmd_trans_huge(*pmd) || pmd_devmap(*pmd)) { if (next - addr != HPAGE_PMD_SIZE) { - VM_BUG_ON_VMA(!rwsem_is_locked(&tlb->mm->mmap_sem), vma); + VM_BUG_ON_VMA(vma_is_anonymous(vma) && + !rwsem_is_locked(&tlb->mm->mmap_sem), vma); split_huge_pmd(vma, pmd, addr); } else if (zap_huge_pmd(tlb, vma, pmd, addr)) goto next; diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 76a0e6e56e05..5d1d9dd9a379 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -534,7 +534,7 @@ retry: nid = page_to_nid(page); if (node_isset(nid, *qp->nmask) == !!(flags & MPOL_MF_INVERT)) continue; - if (PageTransCompound(page) && PageAnon(page)) { + if (PageTransCompound(page)) { get_page(page); pte_unmap_unlock(pte, ptl); lock_page(page); diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 11ff8f758631..2c8d5386665d 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2554,6 +2554,7 @@ int set_page_dirty(struct page *page) { struct address_space *mapping = page_mapping(page); + page = compound_head(page); if (likely(mapping)) { int (*spd)(struct page *) = mapping->a_ops->set_page_dirty; /* diff --git a/mm/shmem.c b/mm/shmem.c index e7c2a69ff410..c31216806721 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -173,10 +173,13 @@ static inline int shmem_reacct_size(unsigned long flags, * shmem_getpage reports shmem_acct_block failure as -ENOSPC not -ENOMEM, * so that a failure on a sparse tmpfs mapping will give SIGBUS not OOM. */ -static inline int shmem_acct_block(unsigned long flags) +static inline int shmem_acct_block(unsigned long flags, long pages) { - return (flags & VM_NORESERVE) ? - security_vm_enough_memory_mm(current->mm, VM_ACCT(PAGE_CACHE_SIZE)) : 0; + if (!(flags & VM_NORESERVE)) + return 0; + + return security_vm_enough_memory_mm(current->mm, + pages * VM_ACCT(PAGE_CACHE_SIZE)); } static inline void shmem_unacct_blocks(unsigned long flags, long pages) @@ -376,30 +379,55 @@ static int shmem_add_to_page_cache(struct page *page, struct address_space *mapping, pgoff_t index, void *expected) { - int error; + int error, nr = hpage_nr_pages(page); + VM_BUG_ON_PAGE(PageTail(page), page); + VM_BUG_ON_PAGE(index != round_down(index, nr), page); VM_BUG_ON_PAGE(!PageLocked(page), page); VM_BUG_ON_PAGE(!PageSwapBacked(page), page); + VM_BUG_ON(expected && PageTransHuge(page)); - page_cache_get(page); + atomic_add(nr, &page->_count); page->mapping = mapping; page->index = index; spin_lock_irq(&mapping->tree_lock); - if (!expected) + if (PageTransHuge(page)) { + void __rcu **results; + pgoff_t idx; + int i; + + error = 0; + if (radix_tree_gang_lookup_slot(&mapping->page_tree, + &results, &idx, index, 1) && + idx < index + HPAGE_PMD_NR) { + error = -EEXIST; + } + + if (!error) { + for (i = 0; i < HPAGE_PMD_NR; i++) { + error = radix_tree_insert(&mapping->page_tree, + index + i, page + i); + VM_BUG_ON(error); + } + count_vm_event(THP_FILE_ALLOC); + } + } else if (!expected) { error = radix_tree_insert(&mapping->page_tree, index, page); - else + } else { error = shmem_radix_tree_replace(mapping, index, expected, page); + } + if (!error) { - mapping->nrpages++; - __inc_zone_page_state(page, NR_FILE_PAGES); - __inc_zone_page_state(page, NR_SHMEM); + mapping->nrpages += nr; + __mod_zone_page_state(page_zone(page), NR_FILE_PAGES, nr); + __mod_zone_page_state(page_zone(page), NR_SHMEM, nr); spin_unlock_irq(&mapping->tree_lock); } else { page->mapping = NULL; spin_unlock_irq(&mapping->tree_lock); - page_cache_release(page); + atomic_sub(nr, &page->_count); } return error; } @@ -412,6 +440,8 @@ static void shmem_delete_from_page_cache(struct page *page, void *radswap) struct address_space *mapping = page->mapping; int error; + VM_BUG_ON_PAGE(PageCompound(page), page); + spin_lock_irq(&mapping->tree_lock); error = shmem_radix_tree_replace(mapping, page->index, page, radswap); page->mapping = NULL; @@ -596,10 +626,33 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, continue; } + VM_BUG_ON_PAGE(page_to_pgoff(page) != index, page); + if (!trylock_page(page)) continue; + + if (PageTransTail(page)) { + /* Middle of THP: zero out the page */ + clear_highpage(page); + unlock_page(page); + continue; + } else if (PageTransHuge(page)) { + if (index == round_down(end, HPAGE_PMD_NR)) { + /* + * Range ends in the middle of THP: + * zero out the page + */ + clear_highpage(page); + unlock_page(page); + continue; + } + index += HPAGE_PMD_NR - 1; + i += HPAGE_PMD_NR - 1; + } + if (!unfalloc || !PageUptodate(page)) { - if (page->mapping == mapping) { + VM_BUG_ON_PAGE(PageTail(page), page); + if (page_mapping(page) == mapping) { VM_BUG_ON_PAGE(PageWriteback(page), page); truncate_inode_page(mapping, page); } @@ -675,8 +728,36 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, } lock_page(page); + + if (PageTransTail(page)) { + /* Middle of THP: zero out the page */ + clear_highpage(page); + unlock_page(page); + /* + * Partial thp truncate due 'start' in middle + * of THP: don't need to look on these pages + * again on !pvec.nr restart. + */ + if (index != round_down(end, HPAGE_PMD_NR)) + start++; + continue; + } else if (PageTransHuge(page)) { + if (index == round_down(end, HPAGE_PMD_NR)) { + /* + * Range ends in the middle of THP: + * zero out the page + */ + clear_highpage(page); + unlock_page(page); + continue; + } + index += HPAGE_PMD_NR - 1; + i += HPAGE_PMD_NR - 1; + } + if (!unfalloc || !PageUptodate(page)) { - if (page->mapping == mapping) { + VM_BUG_ON_PAGE(PageTail(page), page); + if (page_mapping(page) == mapping) { VM_BUG_ON_PAGE(PageWriteback(page), page); truncate_inode_page(mapping, page); } else { @@ -935,6 +1016,7 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc) swp_entry_t swap; pgoff_t index; + VM_BUG_ON_PAGE(PageCompound(page), page); BUG_ON(!PageLocked(page)); mapping = page->mapping; index = page->index; @@ -1034,8 +1116,8 @@ redirty: return 0; } -#ifdef CONFIG_NUMA #ifdef CONFIG_TMPFS +#ifdef CONFIG_NUMA static void shmem_show_mpol(struct seq_file *seq, struct mempolicy *mpol) { char buffer[64]; @@ -1059,68 +1141,129 @@ static struct mempolicy *shmem_get_sbmpol(struct shmem_sb_info *sbinfo) } return mpol; } + +#else + +static void shmem_show_mpol(struct seq_file *seq, struct mempolicy *mpol) +{ +} +#endif /* CONFIG_NUMA */ #endif /* CONFIG_TMPFS */ +static void shmem_pseudo_vma_init(struct vm_area_struct *vma, + struct shmem_inode_info *info, pgoff_t index) +{ + /* Create a pseudo vma that just contains the policy */ + vma->vm_start = 0; + /* Bias interleave by inode number to distribute better across nodes */ + vma->vm_pgoff = index + info->vfs_inode.i_ino; + vma->vm_ops = NULL; + +#ifdef CONFIG_NUMA + vma->vm_policy = mpol_shared_policy_lookup(&info->policy, index); +#endif /* CONFIG_NUMA */ +} + +static void shmem_pseudo_vma_destroy(struct vm_area_struct *vma) +{ +#ifdef CONFIG_NUMA + /* Drop reference taken by mpol_shared_policy_lookup() */ + mpol_cond_put(vma->vm_policy); +#endif +} + static struct page *shmem_swapin(swp_entry_t swap, gfp_t gfp, struct shmem_inode_info *info, pgoff_t index) { struct vm_area_struct pvma; struct page *page; - /* Create a pseudo vma that just contains the policy */ - pvma.vm_start = 0; - /* Bias interleave by inode number to distribute better across nodes */ - pvma.vm_pgoff = index + info->vfs_inode.i_ino; - pvma.vm_ops = NULL; - pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, index); - + shmem_pseudo_vma_init(&pvma, info, index); page = swapin_readahead(swap, gfp, &pvma, 0); - - /* Drop reference taken by mpol_shared_policy_lookup() */ - mpol_cond_put(pvma.vm_policy); + shmem_pseudo_vma_destroy(&pvma); return page; } -static struct page *shmem_alloc_page(gfp_t gfp, - struct shmem_inode_info *info, pgoff_t index) +static struct page *shmem_alloc_hugepage(gfp_t gfp, + struct shmem_inode_info *info, pgoff_t index) { struct vm_area_struct pvma; + struct inode *inode = &info->vfs_inode; + struct address_space *mapping = inode->i_mapping; + pgoff_t idx, hindex = round_down(index, HPAGE_PMD_NR); + void __rcu **results; struct page *page; - /* Create a pseudo vma that just contains the policy */ - pvma.vm_start = 0; - /* Bias interleave by inode number to distribute better across nodes */ - pvma.vm_pgoff = index + info->vfs_inode.i_ino; - pvma.vm_ops = NULL; - pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, index); - - page = alloc_page_vma(gfp, &pvma, 0); + if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) + return NULL; - /* Drop reference taken by mpol_shared_policy_lookup() */ - mpol_cond_put(pvma.vm_policy); + rcu_read_lock(); + if (radix_tree_gang_lookup_slot(&mapping->page_tree, &results, &idx, + hindex, 1) && idx < hindex + HPAGE_PMD_NR) { + rcu_read_unlock(); + return NULL; + } + rcu_read_unlock(); + shmem_pseudo_vma_init(&pvma, info, hindex); + page = alloc_pages_vma(gfp | __GFP_COMP | __GFP_NORETRY | __GFP_NOWARN, + HPAGE_PMD_ORDER, &pvma, 0, numa_node_id(), true); + shmem_pseudo_vma_destroy(&pvma); + if (page) + prep_transhuge_page(page); return page; } -#else /* !CONFIG_NUMA */ -#ifdef CONFIG_TMPFS -static inline void shmem_show_mpol(struct seq_file *seq, struct mempolicy *mpol) -{ -} -#endif /* CONFIG_TMPFS */ -static inline struct page *shmem_swapin(swp_entry_t swap, gfp_t gfp, +static struct page *shmem_alloc_page(gfp_t gfp, struct shmem_inode_info *info, pgoff_t index) { - return swapin_readahead(swap, gfp, NULL, 0); + struct vm_area_struct pvma; + struct page *page; + + shmem_pseudo_vma_init(&pvma, info, index); + page = alloc_page_vma(gfp, &pvma, 0); + shmem_pseudo_vma_destroy(&pvma); + + return page; } -static inline struct page *shmem_alloc_page(gfp_t gfp, - struct shmem_inode_info *info, pgoff_t index) +static struct page *shmem_alloc_and_acct_page(gfp_t gfp, + struct shmem_inode_info *info, struct shmem_sb_info *sbinfo, + pgoff_t index, bool huge) { - return alloc_page(gfp); + struct page *page; + int nr; + int err = -ENOSPC; + + if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) + huge = false; + nr = huge ? HPAGE_PMD_NR : 1; + + if (shmem_acct_block(info->flags, nr)) + goto failed; + if (sbinfo->max_blocks) { + if (percpu_counter_compare(&sbinfo->used_blocks, + sbinfo->max_blocks + nr) > 0) + goto unacct; + percpu_counter_add(&sbinfo->used_blocks, nr); + } + + if (huge) + page = shmem_alloc_hugepage(gfp, info, index); + else + page = shmem_alloc_page(gfp, info, index); + if (page) + return page; + + err = -ENOMEM; + if (sbinfo->max_blocks) + percpu_counter_add(&sbinfo->used_blocks, -nr); +unacct: + shmem_unacct_blocks(info->flags, nr); +failed: + return ERR_PTR(err); } -#endif /* CONFIG_NUMA */ #if !defined(CONFIG_NUMA) || !defined(CONFIG_TMPFS) static inline struct mempolicy *shmem_get_sbmpol(struct shmem_sb_info *sbinfo) @@ -1228,6 +1371,7 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, struct mem_cgroup *memcg; struct page *page; swp_entry_t swap; + pgoff_t hindex = index; int error; int once = 0; int alloced = 0; @@ -1344,50 +1488,75 @@ repeat: swap_free(swap); } else { - if (shmem_acct_block(info->flags)) { - error = -ENOSPC; - goto failed; - } - if (sbinfo->max_blocks) { - if (percpu_counter_compare(&sbinfo->used_blocks, - sbinfo->max_blocks) >= 0) { - error = -ENOSPC; - goto unacct; - } - percpu_counter_inc(&sbinfo->used_blocks); + /* shmem_symlink() */ + if (mapping->a_ops != &shmem_aops) + goto alloc_nohuge; + if (shmem_huge == SHMEM_HUGE_DENY) + goto alloc_nohuge; + if (shmem_huge == SHMEM_HUGE_FORCE) + goto alloc_huge; + switch (sbinfo->huge) { + loff_t i_size; + pgoff_t off; + case SHMEM_HUGE_NEVER: + goto alloc_nohuge; + case SHMEM_HUGE_WITHIN_SIZE: + off = round_up(index, HPAGE_PMD_NR); + i_size = round_up(i_size_read(inode), PAGE_CACHE_SIZE); + if (i_size >> PAGE_CACHE_SHIFT >= off) + goto alloc_huge; + /* fallthrough */ + case SHMEM_HUGE_ADVISE: + /* TODO: wire up fadvise()/madvise() */ + goto alloc_nohuge; } - page = shmem_alloc_page(gfp, info, index); - if (!page) { - error = -ENOMEM; - goto decused; +alloc_huge: + page = shmem_alloc_and_acct_page(gfp, info, sbinfo, + index, true); + if (IS_ERR(page)) { +alloc_nohuge: page = shmem_alloc_and_acct_page(gfp, info, sbinfo, + index, false); + } + if (IS_ERR(page)) { + error = PTR_ERR(page); + page = NULL; + goto failed; } + if (PageTransHuge(page)) + hindex = round_down(index, HPAGE_PMD_NR); + else + hindex = index; + __SetPageSwapBacked(page); __SetPageLocked(page); if (sgp == SGP_WRITE) __SetPageReferenced(page); error = mem_cgroup_try_charge(page, current->mm, gfp, &memcg, - false); + PageTransHuge(page)); if (error) - goto decused; - error = radix_tree_maybe_preload(gfp & GFP_RECLAIM_MASK); + goto unacct; + error = radix_tree_maybe_preload_order(gfp & GFP_RECLAIM_MASK, + compound_order(page)); if (!error) { - error = shmem_add_to_page_cache(page, mapping, index, + error = shmem_add_to_page_cache(page, mapping, hindex, NULL); radix_tree_preload_end(); } if (error) { - mem_cgroup_cancel_charge(page, memcg, false); - goto decused; + mem_cgroup_cancel_charge(page, memcg, + PageTransHuge(page)); + goto unacct; } - mem_cgroup_commit_charge(page, memcg, false, false); + mem_cgroup_commit_charge(page, memcg, false, + PageTransHuge(page)); lru_cache_add_anon(page); spin_lock(&info->lock); - info->alloced++; - inode->i_blocks += BLOCKS_PER_PAGE; + info->alloced += 1 << compound_order(page); + inode->i_blocks += BLOCKS_PER_PAGE << compound_order(page); shmem_recalc_inode(inode); spin_unlock(&info->lock); alloced = true; @@ -1403,10 +1572,15 @@ clear: * but SGP_FALLOC on a page fallocated earlier must initialize * it now, lest undo on failure cancel our earlier guarantee. */ - if (sgp != SGP_WRITE) { - clear_highpage(page); - flush_dcache_page(page); - SetPageUptodate(page); + if (sgp != SGP_WRITE && !PageUptodate(page)) { + struct page *head = compound_head(page); + int i; + + for (i = 0; i < (1 << compound_order(head)); i++) { + clear_highpage(head + i); + flush_dcache_page(head + i); + } + SetPageUptodate(head); } if (sgp == SGP_DIRTY) set_page_dirty(page); @@ -1425,17 +1599,23 @@ clear: error = -EINVAL; goto unlock; } - *pagep = page; + *pagep = page + index - hindex; return 0; /* * Error recovery. */ -decused: - if (sbinfo->max_blocks) - percpu_counter_add(&sbinfo->used_blocks, -1); unacct: - shmem_unacct_blocks(info->flags, 1); + if (sbinfo->max_blocks) + percpu_counter_add(&sbinfo->used_blocks, + 1 << compound_order(page)); + shmem_unacct_blocks(info->flags, 1 << compound_order(page)); + + if (PageTransHuge(page)) { + unlock_page(page); + page_cache_release(page); + goto alloc_nohuge; + } failed: if (swap.val && !shmem_confirm_swap(mapping, index, swap)) error = -EEXIST; @@ -1776,12 +1956,23 @@ shmem_write_end(struct file *file, struct address_space *mapping, i_size_write(inode, pos + copied); if (!PageUptodate(page)) { + struct page *head = compound_head(page); + if (PageTransCompound(page)) { + int i; + + for (i = 0; i < HPAGE_PMD_NR; i++) { + if (head + i == page) + continue; + clear_highpage(head + i); + flush_dcache_page(head + i); + } + } if (copied < PAGE_CACHE_SIZE) { unsigned from = pos & (PAGE_CACHE_SIZE - 1); zero_user_segments(page, 0, from, from + copied, PAGE_CACHE_SIZE); } - SetPageUptodate(page); + SetPageUptodate(head); } set_page_dirty(page); unlock_page(page); diff --git a/mm/swap.c b/mm/swap.c index 09fe5e97714a..5ee5118f45d4 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -291,6 +291,7 @@ static bool need_activate_page_drain(int cpu) void activate_page(struct page *page) { + page = compound_head(page); if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { struct pagevec *pvec = &get_cpu_var(activate_page_pvecs); @@ -315,6 +316,7 @@ void activate_page(struct page *page) { struct zone *zone = page_zone(page); + page = compound_head(page); spin_lock_irq(&zone->lru_lock); __activate_page(page, mem_cgroup_page_lruvec(page, zone), NULL); spin_unlock_irq(&zone->lru_lock); -- 2.7.0