From patchwork Wed Jun 15 20:06:29 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kirill A . Shutemov" X-Patchwork-Id: 9179377 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 23A8C604DB for ; Wed, 15 Jun 2016 20:16:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 10095269E2 for ; Wed, 15 Jun 2016 20:16:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0434027F07; Wed, 15 Jun 2016 20:16:10 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 24A22269E2 for ; Wed, 15 Jun 2016 20:16:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933202AbcFOUPI (ORCPT ); Wed, 15 Jun 2016 16:15:08 -0400 Received: from mga04.intel.com ([192.55.52.120]:17260 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933112AbcFOUHF (ORCPT ); Wed, 15 Jun 2016 16:07:05 -0400 Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga104.fm.intel.com with ESMTP; 15 Jun 2016 13:07:04 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.26,477,1459839600"; d="scan'208";a="122579906" Received: from black.fi.intel.com ([10.237.72.93]) by fmsmga004.fm.intel.com with ESMTP; 15 Jun 2016 13:07:00 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id B389FCD1; Wed, 15 Jun 2016 23:06:49 +0300 (EEST) 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 , Andres Lagar-Cavilla , Ning Qu , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Ebru Akagunduz , "Kirill A. Shutemov" Subject: [PATCHv9-rebased2 24/37] filemap: prepare find and delete operations for huge pages Date: Wed, 15 Jun 2016 23:06:29 +0300 Message-Id: <1466021202-61880-25-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.8.1 In-Reply-To: <1466021202-61880-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1465222029-45942-1-git-send-email-kirill.shutemov@linux.intel.com> <1466021202-61880-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP For now, we would have HPAGE_PMD_NR entries in radix tree for every huge page. That's suboptimal and it will be changed to use Matthew's multi-order entries later. 'add' operation is not changed, because we don't need it to implement hugetmpfs: shmem uses its own implementation. Signed-off-by: Kirill A. Shutemov --- mm/filemap.c | 178 ++++++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 122 insertions(+), 56 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index 1efd2994dccf..21508ea25717 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -114,14 +114,14 @@ static void page_cache_tree_delete(struct address_space *mapping, struct page *page, void *shadow) { struct radix_tree_node *node; + int i, nr = PageHuge(page) ? 1 : hpage_nr_pages(page); - VM_BUG_ON(!PageLocked(page)); - - node = radix_tree_replace_clear_tags(&mapping->page_tree, page->index, - shadow); + VM_BUG_ON_PAGE(!PageLocked(page), page); + VM_BUG_ON_PAGE(PageTail(page), page); + VM_BUG_ON_PAGE(nr != 1 && shadow, page); if (shadow) { - mapping->nrexceptional++; + mapping->nrexceptional += nr; /* * Make sure the nrexceptional update is committed before * the nrpages update so that final truncate racing @@ -130,31 +130,38 @@ static void page_cache_tree_delete(struct address_space *mapping, */ smp_wmb(); } - mapping->nrpages--; - - if (!node) - return; + mapping->nrpages -= nr; - workingset_node_pages_dec(node); - if (shadow) - workingset_node_shadows_inc(node); - else - if (__radix_tree_delete_node(&mapping->page_tree, node)) + for (i = 0; i < nr; i++) { + node = radix_tree_replace_clear_tags(&mapping->page_tree, + page->index + i, shadow); + if (!node) { + VM_BUG_ON_PAGE(nr != 1, page); return; + } - /* - * Track node that only contains shadow entries. DAX mappings contain - * no shadow entries and may contain other exceptional entries so skip - * those. - * - * Avoid acquiring the list_lru lock if already tracked. The - * list_empty() test is safe as node->private_list is - * protected by mapping->tree_lock. - */ - if (!dax_mapping(mapping) && !workingset_node_pages(node) && - list_empty(&node->private_list)) { - node->private_data = mapping; - list_lru_add(&workingset_shadow_nodes, &node->private_list); + workingset_node_pages_dec(node); + if (shadow) + workingset_node_shadows_inc(node); + else + if (__radix_tree_delete_node(&mapping->page_tree, node)) + continue; + + /* + * Track node that only contains shadow entries. DAX mappings + * contain no shadow entries and may contain other exceptional + * entries so skip those. + * + * Avoid acquiring the list_lru lock if already tracked. + * The list_empty() test is safe as node->private_list is + * protected by mapping->tree_lock. + */ + if (!dax_mapping(mapping) && !workingset_node_pages(node) && + list_empty(&node->private_list)) { + node->private_data = mapping; + list_lru_add(&workingset_shadow_nodes, + &node->private_list); + } } } @@ -166,6 +173,7 @@ static void page_cache_tree_delete(struct address_space *mapping, void __delete_from_page_cache(struct page *page, void *shadow) { struct address_space *mapping = page->mapping; + int nr = hpage_nr_pages(page); trace_mm_filemap_delete_from_page_cache(page); /* @@ -178,6 +186,7 @@ void __delete_from_page_cache(struct page *page, void *shadow) else cleancache_invalidate_page(mapping, page); + VM_BUG_ON_PAGE(PageTail(page), page); VM_BUG_ON_PAGE(page_mapped(page), page); if (!IS_ENABLED(CONFIG_DEBUG_VM) && unlikely(page_mapped(page))) { int mapcount; @@ -209,9 +218,9 @@ void __delete_from_page_cache(struct page *page, void *shadow) /* hugetlb pages do not participate in page cache accounting. */ if (!PageHuge(page)) - __dec_zone_page_state(page, NR_FILE_PAGES); + __mod_zone_page_state(page_zone(page), NR_FILE_PAGES, -nr); if (PageSwapBacked(page)) - __dec_zone_page_state(page, NR_SHMEM); + __mod_zone_page_state(page_zone(page), NR_SHMEM, -nr); /* * At this point page must be either written or cleaned by truncate. @@ -235,9 +244,8 @@ void __delete_from_page_cache(struct page *page, void *shadow) */ void delete_from_page_cache(struct page *page) { - struct address_space *mapping = page->mapping; + struct address_space *mapping = page_mapping(page); unsigned long flags; - void (*freepage)(struct page *); BUG_ON(!PageLocked(page)); @@ -250,7 +258,13 @@ void delete_from_page_cache(struct page *page) if (freepage) freepage(page); - put_page(page); + + if (PageTransHuge(page) && !PageHuge(page)) { + page_ref_sub(page, HPAGE_PMD_NR); + VM_BUG_ON_PAGE(page_count(page) <= 0, page); + } else { + put_page(page); + } } EXPORT_SYMBOL(delete_from_page_cache); @@ -1053,7 +1067,7 @@ EXPORT_SYMBOL(page_cache_prev_hole); struct page *find_get_entry(struct address_space *mapping, pgoff_t offset) { void **pagep; - struct page *page; + struct page *head, *page; rcu_read_lock(); repeat: @@ -1073,8 +1087,16 @@ repeat: */ goto out; } - if (!page_cache_get_speculative(page)) + + head = compound_head(page); + if (!page_cache_get_speculative(head)) + goto repeat; + + /* The page was split under us? */ + if (compound_head(page) != head) { + put_page(head); goto repeat; + } /* * Has the page moved? @@ -1082,7 +1104,7 @@ repeat: * include/linux/pagemap.h for details. */ if (unlikely(page != *pagep)) { - put_page(page); + put_page(head); goto repeat; } } @@ -1118,12 +1140,12 @@ repeat: if (page && !radix_tree_exception(page)) { lock_page(page); /* Has the page been truncated? */ - if (unlikely(page->mapping != mapping)) { + if (unlikely(page_mapping(page) != mapping)) { unlock_page(page); put_page(page); goto repeat; } - VM_BUG_ON_PAGE(page->index != offset, page); + VM_BUG_ON_PAGE(page_to_pgoff(page) != offset, page); } return page; } @@ -1255,7 +1277,7 @@ unsigned find_get_entries(struct address_space *mapping, rcu_read_lock(); radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) { - struct page *page; + struct page *head, *page; repeat: page = radix_tree_deref_slot(slot); if (unlikely(!page)) @@ -1272,12 +1294,20 @@ repeat: */ goto export; } - if (!page_cache_get_speculative(page)) + + head = compound_head(page); + if (!page_cache_get_speculative(head)) + goto repeat; + + /* The page was split under us? */ + if (compound_head(page) != head) { + put_page(head); goto repeat; + } /* Has the page moved? */ if (unlikely(page != *slot)) { - put_page(page); + put_page(head); goto repeat; } export: @@ -1318,7 +1348,7 @@ unsigned find_get_pages(struct address_space *mapping, pgoff_t start, rcu_read_lock(); radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) { - struct page *page; + struct page *head, *page; repeat: page = radix_tree_deref_slot(slot); if (unlikely(!page)) @@ -1337,12 +1367,19 @@ repeat: continue; } - if (!page_cache_get_speculative(page)) + head = compound_head(page); + if (!page_cache_get_speculative(head)) + goto repeat; + + /* The page was split under us? */ + if (compound_head(page) != head) { + put_page(head); goto repeat; + } /* Has the page moved? */ if (unlikely(page != *slot)) { - put_page(page); + put_page(head); goto repeat; } @@ -1379,7 +1416,7 @@ unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t index, rcu_read_lock(); radix_tree_for_each_contig(slot, &mapping->page_tree, &iter, index) { - struct page *page; + struct page *head, *page; repeat: page = radix_tree_deref_slot(slot); /* The hole, there no reason to continue */ @@ -1399,12 +1436,19 @@ repeat: break; } - if (!page_cache_get_speculative(page)) + head = compound_head(page); + if (!page_cache_get_speculative(head)) + goto repeat; + + /* The page was split under us? */ + if (compound_head(page) != head) { + put_page(head); goto repeat; + } /* Has the page moved? */ if (unlikely(page != *slot)) { - put_page(page); + put_page(head); goto repeat; } @@ -1413,7 +1457,7 @@ repeat: * otherwise we can get both false positives and false * negatives, which is just confusing to the caller. */ - if (page->mapping == NULL || page->index != iter.index) { + if (page->mapping == NULL || page_to_pgoff(page) != iter.index) { put_page(page); break; } @@ -1451,7 +1495,7 @@ unsigned find_get_pages_tag(struct address_space *mapping, pgoff_t *index, rcu_read_lock(); radix_tree_for_each_tagged(slot, &mapping->page_tree, &iter, *index, tag) { - struct page *page; + struct page *head, *page; repeat: page = radix_tree_deref_slot(slot); if (unlikely(!page)) @@ -1476,12 +1520,19 @@ repeat: continue; } - if (!page_cache_get_speculative(page)) + head = compound_head(page); + if (!page_cache_get_speculative(head)) goto repeat; + /* The page was split under us? */ + if (compound_head(page) != head) { + put_page(head); + goto repeat; + } + /* Has the page moved? */ if (unlikely(page != *slot)) { - put_page(page); + put_page(head); goto repeat; } @@ -1525,7 +1576,7 @@ unsigned find_get_entries_tag(struct address_space *mapping, pgoff_t start, rcu_read_lock(); radix_tree_for_each_tagged(slot, &mapping->page_tree, &iter, start, tag) { - struct page *page; + struct page *head, *page; repeat: page = radix_tree_deref_slot(slot); if (unlikely(!page)) @@ -1543,12 +1594,20 @@ repeat: */ goto export; } - if (!page_cache_get_speculative(page)) + + head = compound_head(page); + if (!page_cache_get_speculative(head)) goto repeat; + /* The page was split under us? */ + if (compound_head(page) != head) { + put_page(head); + goto repeat; + } + /* Has the page moved? */ if (unlikely(page != *slot)) { - put_page(page); + put_page(head); goto repeat; } export: @@ -2137,7 +2196,7 @@ void filemap_map_pages(struct fault_env *fe, struct address_space *mapping = file->f_mapping; pgoff_t last_pgoff = start_pgoff; loff_t size; - struct page *page; + struct page *head, *page; rcu_read_lock(); radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, @@ -2156,12 +2215,19 @@ repeat: goto next; } - if (!page_cache_get_speculative(page)) + head = compound_head(page); + if (!page_cache_get_speculative(head)) goto repeat; + /* The page was split under us? */ + if (compound_head(page) != head) { + put_page(head); + goto repeat; + } + /* Has the page moved? */ if (unlikely(page != *slot)) { - put_page(page); + put_page(head); goto repeat; }