From patchwork Tue Jun 22 11:40:52 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12336947 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=-16.5 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=unavailable 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 72B30C48BDF for ; Tue, 22 Jun 2021 11:48:00 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 26DC761374 for ; Tue, 22 Jun 2021 11:48:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 26DC761374 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 B83956B0062; Tue, 22 Jun 2021 07:47:59 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B33BE6B006C; Tue, 22 Jun 2021 07:47:59 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9FC4B6B0070; Tue, 22 Jun 2021 07:47:59 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 6F8396B0062 for ; Tue, 22 Jun 2021 07:47:59 -0400 (EDT) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 0A644180AD82F for ; Tue, 22 Jun 2021 11:47:59 +0000 (UTC) X-FDA: 78281185878.02.8C0FD84 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf16.hostedemail.com (Postfix) with ESMTP id 4FE508019375 for ; Tue, 22 Jun 2021 11:47:58 +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=wIdCyN89iXDtUxEEjmkgWjTfwAytP6IYAb9qOX1IpYM=; b=k4ePt86sZ7cM6a6+9f0hKiO0P1 /TF1TLUATiTAy3J1lE2SuIJcAyjdC4oJyPnRQFCtl0Qst8oapEgets5cuBf6n/aqEXWKuzc2o8hJq Ap1x9iMVPUMElIzmUCe831JRBFHgPFuryD0oJnd1TCoXgwDLu8u4rfs5S53aVRorar3akbUK/5N+G MxlCL6+qLFSMRHfziAt2f8m/g9zrDowJHm6fi9T/H2d9LBVxZbpdZ5hfPvFpuU++P7OxX51/qY6H7 9WYrsiLvYDPNAlgbAW9e0NBzyQfn51wkr4LX1zAxvdgpL0PwH5SHqbILwu9pLOI3pXRFQOm65+/AM 6gN5KazQ==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1lverR-00EDki-IK; Tue, 22 Jun 2021 11:46:44 +0000 From: "Matthew Wilcox (Oracle)" To: akpm@linux-foundation.org Cc: "Matthew Wilcox (Oracle)" , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Zi Yan , Christoph Hellwig , Jeff Layton , "Kirill A . Shutemov" , Vlastimil Babka , William Kucharski , David Howells Subject: [PATCH v12 07/33] mm: Add folio_put() Date: Tue, 22 Jun 2021 12:40:52 +0100 Message-Id: <20210622114118.3388190-8-willy@infradead.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210622114118.3388190-1-willy@infradead.org> References: <20210622114118.3388190-1-willy@infradead.org> MIME-Version: 1.0 Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=k4ePt86s; dmarc=none; spf=none (imf16.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org X-Stat-Signature: i6p867sr9c5nmfom183oewdpgsz1wfqs X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 4FE508019375 X-HE-Tag: 1624362478-109841 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: If we know we have a folio, we can call folio_put() instead of put_page() and save the overhead of calling compound_head(). Also skips the devmap checks. This commit looks like it should be a no-op, but actually saves 684 bytes of text with the distro-derived config that I'm testing. Some functions grow a little while others shrink. I presume the compiler is making different inlining decisions. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Zi Yan Reviewed-by: Christoph Hellwig Acked-by: Jeff Layton Acked-by: Kirill A. Shutemov Acked-by: Vlastimil Babka Reviewed-by: William Kucharski Reviewed-by: David Howells --- include/linux/mm.h | 33 ++++++++++++++++++++++++++++----- 1 file changed, 28 insertions(+), 5 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index f0025bd2c2ad..08a80e2eb292 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -751,6 +751,11 @@ static inline int put_page_testzero(struct page *page) return page_ref_dec_and_test(page); } +static inline int folio_put_testzero(struct folio *folio) +{ + return put_page_testzero(&folio->page); +} + /* * Try to grab a ref unless the page has a refcount of zero, return false if * that is the case. @@ -1247,9 +1252,28 @@ static inline __must_check bool try_get_page(struct page *page) return true; } +/** + * folio_put - Decrement the reference count on a folio. + * @folio: The folio. + * + * If the folio's reference count reaches zero, the memory will be + * released back to the page allocator and may be used by another + * allocation immediately. Do not access the memory or the struct folio + * after calling folio_put() unless you can be sure that it wasn't the + * last reference. + * + * Context: May be called in process or interrupt context, but not in NMI + * context. May be called while holding a spinlock. + */ +static inline void folio_put(struct folio *folio) +{ + if (folio_put_testzero(folio)) + __put_page(&folio->page); +} + static inline void put_page(struct page *page) { - page = compound_head(page); + struct folio *folio = page_folio(page); /* * For devmap managed pages we need to catch refcount transition from @@ -1257,13 +1281,12 @@ static inline void put_page(struct page *page) * need to inform the device driver through callback. See * include/linux/memremap.h and HMM for details. */ - if (page_is_devmap_managed(page)) { - put_devmap_managed_page(page); + if (page_is_devmap_managed(&folio->page)) { + put_devmap_managed_page(&folio->page); return; } - if (put_page_testzero(page)) - __put_page(page); + folio_put(folio); } /*