From patchwork Mon Jan 18 17:01:35 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12027847 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 B4666C433DB for ; Mon, 18 Jan 2021 17:02:42 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 527D4222BB for ; Mon, 18 Jan 2021 17:02:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 527D4222BB 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 7BB3C6B00F6; Mon, 18 Jan 2021 12:02:37 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 76C766B00F8; Mon, 18 Jan 2021 12:02:37 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6A85D6B00F9; Mon, 18 Jan 2021 12:02:37 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0066.hostedemail.com [216.40.44.66]) by kanga.kvack.org (Postfix) with ESMTP id 570836B00F8 for ; Mon, 18 Jan 2021 12:02:37 -0500 (EST) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 1A83B3652 for ; Mon, 18 Jan 2021 17:02:37 +0000 (UTC) X-FDA: 77719514754.22.cast07_1b05d3d2754a Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin22.hostedemail.com (Postfix) with ESMTP id EEEED18038E60 for ; Mon, 18 Jan 2021 17:02:36 +0000 (UTC) X-HE-Tag: cast07_1b05d3d2754a X-Filterd-Recvd-Size: 6281 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf10.hostedemail.com (Postfix) with ESMTP for ; Mon, 18 Jan 2021 17:02:36 +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=OGxJBD+EGZ8LUoa8kIajxEh7bdJutIWgtVED3sb4XOc=; b=Jxh1C4kkAM388NqB+0T+q7yVDi ZN4q3vcsEmq6TfpEGzU/8bcI5nv2rDuVsejyG23ktGfe7OvwPmnHm+90AoItpyC8xHhObEnaVoFVt NBCPGr1E/jH8+zZeSralkjTMCEqOmk8gz04nEVYVLt9ndDMjkF2h1wIKmKx8JcdPdM3+ALypgbr4x iZpz5SwL8SgambrI8xMh8l14s91yRtVo/TVrPyvfcItvQlfk0NAA/Q2boOaeUd7ScBzMBSHv716LN 3BsCPoczw94xrFwunVwdlK7MjdBF53VW3Y/XDoxt0AApi0wkOv2E3wTKw2/io+rEKJ4g+dHYHAwvT EiTziwmQ==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1l1Xv3-00D7LY-5e; Mon, 18 Jan 2021 17:02:23 +0000 From: "Matthew Wilcox (Oracle)" To: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Cc: "Matthew Wilcox (Oracle)" , linux-kernel@vger.kernel.org Subject: [PATCH v2 14/27] mm: Add lock_folio Date: Mon, 18 Jan 2021 17:01:35 +0000 Message-Id: <20210118170148.3126186-15-willy@infradead.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210118170148.3126186-1-willy@infradead.org> References: <20210118170148.3126186-1-willy@infradead.org> MIME-Version: 1.0 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: This is like lock_page() but for use by callers who know they have a folio. Convert __lock_page() to be __lock_folio(). This saves one call to compound_head() per contended call to lock_page(). Signed-off-by: Matthew Wilcox (Oracle) --- include/linux/pagemap.h | 21 +++++++++++++++------ mm/filemap.c | 29 +++++++++++++++-------------- 2 files changed, 30 insertions(+), 20 deletions(-) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 44675104008b..03b67915b0f7 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -618,7 +618,7 @@ static inline bool wake_page_match(struct wait_page_queue *wait_page, return true; } -extern void __lock_page(struct page *page); +void __lock_folio(struct folio *folio); 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, @@ -639,13 +639,24 @@ static inline void unlock_page(struct page *page) return unlock_folio(page_folio(page)); } +static inline bool trylock_folio(struct folio *folio) +{ + return likely(!test_and_set_bit_lock(PG_locked, folio_flags(folio))); +} + /* * Return true if the page was successfully locked */ static inline int trylock_page(struct page *page) { - page = compound_head(page); - return (likely(!test_and_set_bit_lock(PG_locked, &page->flags))); + return trylock_folio(page_folio(page)); +} + +static inline void lock_folio(struct folio *folio) +{ + might_sleep(); + if (!trylock_folio(folio)) + __lock_folio(folio); } /* @@ -653,9 +664,7 @@ static inline int trylock_page(struct page *page) */ static inline void lock_page(struct page *page) { - might_sleep(); - if (!trylock_page(page)) - __lock_page(page); + lock_folio(page_folio(page)); } /* diff --git a/mm/filemap.c b/mm/filemap.c index 31470b36ac89..167552fad5a6 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1155,7 +1155,7 @@ static void wake_up_page(struct page *page, int bit) */ enum behavior { EXCLUSIVE, /* Hold ref to page and take the bit when woken, like - * __lock_page() waiting on then setting PG_locked. + * __lock_folio() waiting on then setting PG_locked. */ SHARED, /* Hold ref to page and check the bit when woken, like * wait_on_page_writeback() waiting on PG_writeback. @@ -1518,17 +1518,16 @@ void page_endio(struct page *page, bool is_write, int err) EXPORT_SYMBOL_GPL(page_endio); /** - * __lock_page - get a lock on the page, assuming we need to sleep to get it - * @__page: the page to lock + * __lock_folio - Get a lock on the folio, assuming we need to sleep to get it. + * @folio: The folio to lock */ -void __lock_page(struct page *__page) +void __lock_folio(struct folio *folio) { - struct page *page = compound_head(__page); - wait_queue_head_t *q = page_waitqueue(page); - wait_on_page_bit_common(q, page, PG_locked, TASK_UNINTERRUPTIBLE, + wait_queue_head_t *q = page_waitqueue(&folio->page); + wait_on_page_bit_common(q, &folio->page, PG_locked, TASK_UNINTERRUPTIBLE, EXCLUSIVE); } -EXPORT_SYMBOL(__lock_page); +EXPORT_SYMBOL(__lock_folio); int __lock_page_killable(struct page *__page) { @@ -1582,10 +1581,10 @@ int __lock_page_or_retry(struct page *page, struct mm_struct *mm, return 0; } } else { - __lock_page(page); + __lock_folio(page_folio(page)); } - return 1; + return 1; } /** @@ -2763,7 +2762,9 @@ loff_t mapping_seek_hole_data(struct address_space *mapping, loff_t start, static int lock_page_maybe_drop_mmap(struct vm_fault *vmf, struct page *page, struct file **fpin) { - if (trylock_page(page)) + struct folio *folio = page_folio(page); + + if (trylock_folio(folio)) return 1; /* @@ -2776,7 +2777,7 @@ static int lock_page_maybe_drop_mmap(struct vm_fault *vmf, struct page *page, *fpin = maybe_unlock_mmap_for_io(vmf, *fpin); if (vmf->flags & FAULT_FLAG_KILLABLE) { - if (__lock_page_killable(page)) { + if (__lock_page_killable(&folio->page)) { /* * We didn't have the right flags to drop the mmap_lock, * but all fault_handlers only check for fatal signals @@ -2788,11 +2789,11 @@ static int lock_page_maybe_drop_mmap(struct vm_fault *vmf, struct page *page, return 0; } } else - __lock_page(page); + __lock_folio(folio); + return 1; } - /* * Synchronous readahead happens when we don't even find a page in the page * cache at all. We don't want to perform IO under the mmap sem, so if we have