From patchwork Wed Mar 31 18:47:17 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12176027 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,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 EC418C433B4 for ; Wed, 31 Mar 2021 18:54:01 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9837260FD9 for ; Wed, 31 Mar 2021 18:54:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9837260FD9 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 2981B6B00AA; Wed, 31 Mar 2021 14:54:01 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 26D446B00AB; Wed, 31 Mar 2021 14:54:01 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1391B6B00AC; Wed, 31 Mar 2021 14:54:01 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0082.hostedemail.com [216.40.44.82]) by kanga.kvack.org (Postfix) with ESMTP id ECB536B00AA for ; Wed, 31 Mar 2021 14:54:00 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id ABCAF18017882 for ; Wed, 31 Mar 2021 18:54:00 +0000 (UTC) X-FDA: 77981069040.29.A74E76D Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf20.hostedemail.com (Postfix) with ESMTP id D516BDE for ; Wed, 31 Mar 2021 18:53:59 +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=eALvA/O77cRJCM2bbMtz4dcAWRzHeKR4Y1MxiWEXqaw=; b=Y7yLJ24XbJ2gJcNcVWy1WrTCsj AtLlkJlZ7zQs58rTC1P/uoDAq7QEGZlarB1QLlsqQQde1fB6dH6Zqv5ho1DU/eYrxbd7BdIKs7wMy t1ycEvyJTQ30NvF2qbEZAUmsbFH2x7141Ih83Dhn9sqYCjovmwxL4ycfB59k3TM571XJRZd2ki7nS DUVunLRKJAEwZeQiDSRRtpv13nPqUiNA2xHVVgesr8cyJZ7p2he2cHNznY801BWjZL0ZzsR7BshaY +2SFERHHyRxz9hW+UDPfdNOxWwJ1hiSve53EQ7X8vpdkrUapYMskTmgF3+QncdyLbMbY1xIg/7wwx z6obLPhA==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lRfy1-004zeT-MT; Wed, 31 Mar 2021 18:53:26 +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 v6 16/27] mm/filemap: Add unlock_folio Date: Wed, 31 Mar 2021 19:47:17 +0100 Message-Id: <20210331184728.1188084-17-willy@infradead.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210331184728.1188084-1-willy@infradead.org> References: <20210331184728.1188084-1-willy@infradead.org> MIME-Version: 1.0 X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: D516BDE X-Stat-Signature: 7fruk3fiw1w6mfyw8b8g4xw877oxacwk Received-SPF: none (infradead.org>: No applicable sender policy available) receiver=imf20; identity=mailfrom; envelope-from=""; helo=casper.infradead.org; client-ip=90.155.50.34 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1617216839-600229 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: Convert unlock_page() to call unlock_folio(). By using a folio we avoid a call to compound_head(). This shortens the function from 39 bytes to 25 and removes 4 instructions on x86-64. Because we still have unlock_page(), it's a net increase of 24 bytes of text for the kernel as a whole, but any path that uses unlock_folio() will execute 4 fewer instructions. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig --- include/linux/pagemap.h | 3 ++- mm/filemap.c | 27 ++++++++++----------------- mm/folio-compat.c | 6 ++++++ 3 files changed, 18 insertions(+), 18 deletions(-) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 01082cda7e72..ee83ada556e0 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -719,7 +719,8 @@ extern int __lock_page_killable(struct page *page); extern int __lock_page_async(struct page *page, struct wait_page_queue *wait); extern int __lock_page_or_retry(struct page *page, struct mm_struct *mm, unsigned int flags); -extern void unlock_page(struct page *page); +void unlock_page(struct page *page); +void unlock_folio(struct folio *folio); void unlock_page_private_2(struct page *page); /* diff --git a/mm/filemap.c b/mm/filemap.c index c03463cb72d6..6d320264e5e0 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1435,29 +1435,22 @@ static inline bool clear_bit_unlock_is_negative_byte(long nr, volatile void *mem #endif /** - * unlock_page - unlock a locked page - * @page: the page + * unlock_folio - Unlock a locked folio. + * @folio: The folio. * - * Unlocks the page and wakes up sleepers in wait_on_page_locked(). - * Also wakes sleepers in wait_on_page_writeback() because the wakeup - * mechanism between PageLocked pages and PageWriteback pages is shared. - * But that's OK - sleepers in wait_on_page_writeback() just go back to sleep. + * Unlocks the folio and wakes up any thread sleeping on the page lock. * - * Note that this depends on PG_waiters being the sign bit in the byte - * that contains PG_locked - thus the BUILD_BUG_ON(). That allows us to - * clear the PG_locked bit and test PG_waiters at the same time fairly - * portably (architectures that do LL/SC can test any bit, while x86 can - * test the sign bit). + * Context: May be called from interrupt or process context. May not be + * called from NMI context. */ -void unlock_page(struct page *page) +void unlock_folio(struct folio *folio) { BUILD_BUG_ON(PG_waiters != 7); - page = compound_head(page); - VM_BUG_ON_PAGE(!PageLocked(page), page); - if (clear_bit_unlock_is_negative_byte(PG_locked, &page->flags)) - wake_up_page_bit(page, PG_locked); + VM_BUG_ON_FOLIO(!FolioLocked(folio), folio); + if (clear_bit_unlock_is_negative_byte(PG_locked, folio_flags(folio, 0))) + wake_up_page_bit(&folio->page, PG_locked); } -EXPORT_SYMBOL(unlock_page); +EXPORT_SYMBOL(unlock_folio); /** * unlock_page_private_2 - Unlock a page that's locked with PG_private_2 diff --git a/mm/folio-compat.c b/mm/folio-compat.c index 5e107aa30a62..02798abf19a1 100644 --- a/mm/folio-compat.c +++ b/mm/folio-compat.c @@ -11,3 +11,9 @@ struct address_space *page_mapping(struct page *page) return folio_mapping(page_folio(page)); } EXPORT_SYMBOL(page_mapping); + +void unlock_page(struct page *page) +{ + return unlock_folio(page_folio(page)); +} +EXPORT_SYMBOL(unlock_page);