From patchwork Sat Mar 20 05:40:52 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12152275 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 49B13C433F7 for ; Sat, 20 Mar 2021 05:43:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3A7B261999 for ; Sat, 20 Mar 2021 05:43:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230092AbhCTFnJ (ORCPT ); Sat, 20 Mar 2021 01:43:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54116 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230040AbhCTFnC (ORCPT ); Sat, 20 Mar 2021 01:43:02 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D04F3C061762; Fri, 19 Mar 2021 22:43:01 -0700 (PDT) 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=A+2/OS9003/aHwRRfvYeOI3a09/9GdRT/Dat6O4B5lM=; b=G5I7cnSJJVzHmECcOKtVrGLyVB HKHCO1NawwFMZ2FKC0AtGPTUDAD0NXqX2t6a6lGxJ6Pi9JZpkgoNxIdje2tuqIDX9iRgfnV8tjLBF /BLZgxZp2XEei/WLIJFx+guINjiTDDZEukEWDfDCyeGSVu0yw4cczCmLzziOxTIZbOEFame9K9pn4 zeWCoH/GjF+aHtb05Xf5psY+sF1MKR1rNK9UL0GPvqnNXsNNXgR/dn9Bs8THNfqELBxyyp4CJJC67 PoQAdiBkiiahbxVsyB43UTX+IGLm47LoImBa4SCnIX/h3offl3ZYvHbW4DxdbBvhZPHJgt1Zxkp20 IVgd2Bng==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lNUNk-005Sal-IJ; Sat, 20 Mar 2021 05:42:46 +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 15/27] mm/filemap: Add unlock_folio Date: Sat, 20 Mar 2021 05:40:52 +0000 Message-Id: <20210320054104.1300774-16-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 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org 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) --- 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 90e970f48039..c211868086e0 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -698,7 +698,8 @@ 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 eeeb8e2cc36a..47ac8126a12e 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);