From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5C3CFC433DB for ; Sat, 20 Mar 2021 05:42:54 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F40EE6193E for ; Sat, 20 Mar 2021 05:42:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F40EE6193E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 978598D0005; Sat, 20 Mar 2021 01:42:53 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 95BB26B0093; Sat, 20 Mar 2021 01:42:53 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7C6528D0005; Sat, 20 Mar 2021 01:42:53 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0216.hostedemail.com [216.40.44.216]) by kanga.kvack.org (Postfix) with ESMTP id 615A66B0092 for ; Sat, 20 Mar 2021 01:42:53 -0400 (EDT) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 1F8DC18208266 for ; Sat, 20 Mar 2021 05:42:53 +0000 (UTC) X-FDA: 77939158626.30.6F56CC5 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf08.hostedemail.com (Postfix) with ESMTP id 9089A80192CE for ; Sat, 20 Mar 2021 05:42:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=TogcGtiunGQHXTWVGfbYtEEeOKlg2CcfwBbKvI/9Sic=; b=TwajhSYg65zC2pd2McZvStKm+s eyhJqJEbPH4ESxUnlr2gr41CHw5au0E03GShLLhP+UAmCT7dOPN2EOiqj/9zGdTuMAGrAOOxROYFV zwX3HXWbfflS8XC4A/QAhcl15ZPNCRcA6k6Ja0FrlB37qbiPEpgLA81AKlzNHc7hVC9fSBOFg0H3J UADdccQYE9elg3BhahAhx9UOF0bCy7HoGvjr0U5Kjx+UsAd6hN3Vd3HpNH664QLhQ2N5+1Un+vR7v BuQ/fbfUdLo5G40VZsHjv+Buf4BEMr7rh06ogntOG+zLK047XTD5wblabyhl3rdw3032DXY0VV//z ofKautGg==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lNUNf-005SZ2-7z; Sat, 20 Mar 2021 05:42:36 +0000 From: "Matthew Wilcox (Oracle)" To: linux-mm@kvack.org Cc: "Matthew Wilcox (Oracle)" , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-cachefs@redhat.com, linux-afs@lists.infradead.org Subject: [PATCH v5 13/27] mm/util: Add folio_mapping and folio_file_mapping Date: Sat, 20 Mar 2021 05:40:50 +0000 Message-Id: <20210320054104.1300774-14-willy@infradead.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210320054104.1300774-1-willy@infradead.org> References: <20210320054104.1300774-1-willy@infradead.org> MIME-Version: 1.0 X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 9089A80192CE X-Stat-Signature: 1f7fpafrd351jdoujn39ku4ntwhr7h9i Received-SPF: none (infradead.org>: No applicable sender policy available) receiver=imf08; identity=mailfrom; envelope-from=""; helo=casper.infradead.org; client-ip=90.155.50.34 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1616218968-903843 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: These are the folio equivalent of page_mapping() and page_file_mapping(). Add an out-of-line page_mapping() wrapper around folio_mapping() in order to prevent the page_folio() call from bloating every caller of page_mapping(). Adjust page_file_mapping() and page_mapping_file() to use folios internally. Rename __page_file_mapping() to swapcache_mapping() and change it to take a folio. This ends up saving 186 bytes of text overall. folio_mapping() is 45 bytes shorter than page_mapping() was, but the new page_mapping() wrapper is 30 bytes. The major reduction is a few bytes less in dozens of nfs functions (which call page_file_mapping()). Most of these appear to be a slight change in gcc's register allocation decisions, which allow= : 48 8b 56 08 mov 0x8(%rsi),%rdx 48 8d 42 ff lea -0x1(%rdx),%rax 83 e2 01 and $0x1,%edx 48 0f 44 c6 cmove %rsi,%rax to become: 48 8b 46 08 mov 0x8(%rsi),%rax 48 8d 78 ff lea -0x1(%rax),%rdi a8 01 test $0x1,%al 48 0f 44 fe cmove %rsi,%rdi for a reduction of a single byte. Once the NFS client is converted to use folios, this entire sequence will disappear. Signed-off-by: Matthew Wilcox (Oracle) --- include/linux/mm.h | 14 -------------- include/linux/pagemap.h | 35 +++++++++++++++++++++++++++++++++-- include/linux/swap.h | 6 ++++++ mm/Makefile | 2 +- mm/folio-compat.c | 13 +++++++++++++ mm/swapfile.c | 8 ++++---- mm/util.c | 30 ++++++++++++++++++------------ 7 files changed, 75 insertions(+), 33 deletions(-) create mode 100644 mm/folio-compat.c diff --git a/include/linux/mm.h b/include/linux/mm.h index 8fc7b04a1438..bc626c19f9f8 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1732,19 +1732,6 @@ void page_address_init(void); =20 extern void *page_rmapping(struct page *page); extern struct anon_vma *page_anon_vma(struct page *page); -extern struct address_space *page_mapping(struct page *page); - -extern struct address_space *__page_file_mapping(struct page *); - -static inline -struct address_space *page_file_mapping(struct page *page) -{ - if (unlikely(PageSwapCache(page))) - return __page_file_mapping(page); - - return page->mapping; -} - extern pgoff_t __page_file_index(struct page *page); =20 /* @@ -1759,7 +1746,6 @@ static inline pgoff_t page_index(struct page *page) } =20 bool page_mapped(struct page *page); -struct address_space *page_mapping(struct page *page); =20 /* * Return true only if the page has been allocated with diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index f29c96ed3721..90e970f48039 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -162,14 +162,45 @@ static inline void filemap_nr_thps_dec(struct addre= ss_space *mapping) =20 void release_pages(struct page **pages, int nr); =20 +struct address_space *page_mapping(struct page *); +struct address_space *folio_mapping(struct folio *); +struct address_space *swapcache_mapping(struct folio *); + +/** + * folio_file_mapping - Find the mapping this folio belongs to. + * @folio: The folio. + * + * For folios which are in the page cache, return the mapping that this + * page belongs to. Folios in the swap cache return the mapping of the + * swap file or swap device where the data is stored. This is different + * from the mapping returned by folio_mapping(). The only reason to + * use it is if, like NFS, you return 0 from ->activate_swapfile. + * + * Do not call this for folios which aren't in the page cache or swap ca= che. + */ +static inline struct address_space *folio_file_mapping(struct folio *fol= io) +{ + if (unlikely(FolioSwapCache(folio))) + return swapcache_mapping(folio); + + return folio->page.mapping; +} + +static inline struct address_space *page_file_mapping(struct page *page) +{ + return folio_file_mapping(page_folio(page)); +} + /* * For file cache pages, return the address_space, otherwise return NULL */ static inline struct address_space *page_mapping_file(struct page *page) { - if (unlikely(PageSwapCache(page))) + struct folio *folio =3D page_folio(page); + + if (unlikely(FolioSwapCache(folio))) return NULL; - return page_mapping(page); + return folio_mapping(folio); } =20 /* diff --git a/include/linux/swap.h b/include/linux/swap.h index 4c3a844ac9b4..09316a5c33e9 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -314,6 +314,12 @@ struct vma_swap_readahead { #endif }; =20 +static inline swp_entry_t folio_swap_entry(struct folio *folio) +{ + swp_entry_t entry =3D { .val =3D page_private(&folio->page) }; + return entry; +} + /* linux/mm/workingset.c */ void workingset_age_nonresident(struct lruvec *lruvec, unsigned long nr_= pages); void *workingset_eviction(struct page *page, struct mem_cgroup *target_m= emcg); diff --git a/mm/Makefile b/mm/Makefile index 788c5ce5c0ef..9d6a7e8b5a3c 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -46,7 +46,7 @@ mmu-$(CONFIG_MMU) +=3D process_vm_access.o endif =20 obj-y :=3D filemap.o mempool.o oom_kill.o fadvise.o \ - maccess.o page-writeback.o \ + maccess.o page-writeback.o folio-compat.o \ readahead.o swap.o truncate.o vmscan.o shmem.o \ util.o mmzone.o vmstat.o backing-dev.o \ mm_init.o percpu.o slab_common.o \ diff --git a/mm/folio-compat.c b/mm/folio-compat.c new file mode 100644 index 000000000000..5e107aa30a62 --- /dev/null +++ b/mm/folio-compat.c @@ -0,0 +1,13 @@ +/* + * Compatibility functions which bloat the callers too much to make inli= ne. + * All of the callers of these functions should be converted to use foli= os + * eventually. + */ + +#include + +struct address_space *page_mapping(struct page *page) +{ + return folio_mapping(page_folio(page)); +} +EXPORT_SYMBOL(page_mapping); diff --git a/mm/swapfile.c b/mm/swapfile.c index 149e77454e3c..d0ee24239a83 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -3533,13 +3533,13 @@ struct swap_info_struct *page_swap_info(struct pa= ge *page) } =20 /* - * out-of-line __page_file_ methods to avoid include hell. + * out-of-line methods to avoid include hell. */ -struct address_space *__page_file_mapping(struct page *page) +struct address_space *swapcache_mapping(struct folio *folio) { - return page_swap_info(page)->swap_file->f_mapping; + return page_swap_info(&folio->page)->swap_file->f_mapping; } -EXPORT_SYMBOL_GPL(__page_file_mapping); +EXPORT_SYMBOL_GPL(swapcache_mapping); =20 pgoff_t __page_file_index(struct page *page) { diff --git a/mm/util.c b/mm/util.c index 0b6dd9d81da7..c4ed5b919c7d 100644 --- a/mm/util.c +++ b/mm/util.c @@ -686,30 +686,36 @@ struct anon_vma *page_anon_vma(struct page *page) return __page_rmapping(page); } =20 -struct address_space *page_mapping(struct page *page) +/** + * folio_mapping - Find the mapping where this folio is stored. + * @folio: The folio. + * + * For folios which are in the page cache, return the mapping that this + * page belongs to. Folios in the swap cache return the swap mapping + * this page is stored in (which is different from the mapping for the + * swap file or swap device where the data is stored). + * + * You can call this for folios which aren't in the swap cache or page + * cache and it will return NULL. + */ +struct address_space *folio_mapping(struct folio *folio) { struct address_space *mapping; =20 - page =3D compound_head(page); - /* This happens if someone calls flush_dcache_page on slab page */ - if (unlikely(PageSlab(page))) + if (unlikely(FolioSlab(folio))) return NULL; =20 - if (unlikely(PageSwapCache(page))) { - swp_entry_t entry; - - entry.val =3D page_private(page); - return swap_address_space(entry); - } + if (unlikely(FolioSwapCache(folio))) + return swap_address_space(folio_swap_entry(folio)); =20 - mapping =3D page->mapping; + mapping =3D folio->page.mapping; if ((unsigned long)mapping & PAGE_MAPPING_ANON) return NULL; =20 return (void *)((unsigned long)mapping & ~PAGE_MAPPING_FLAGS); } -EXPORT_SYMBOL(page_mapping); +EXPORT_SYMBOL(folio_mapping); =20 /* Slow path of page_mapcount() for compound pages */ int __page_mapcount(struct page *page) --=20 2.30.2