From patchwork Sat Mar 20 05:40:45 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12152309 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 562E2C433C1 for ; Sat, 20 Mar 2021 05:42:22 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 026F661999 for ; Sat, 20 Mar 2021 05:42:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 026F661999 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 8B41C8D0009; Sat, 20 Mar 2021 01:42:21 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 889DB6B0082; Sat, 20 Mar 2021 01:42:21 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 752538D0009; Sat, 20 Mar 2021 01:42:21 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0061.hostedemail.com [216.40.44.61]) by kanga.kvack.org (Postfix) with ESMTP id 5C8A26B0081 for ; Sat, 20 Mar 2021 01:42:21 -0400 (EDT) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 1DEB518208266 for ; Sat, 20 Mar 2021 05:42:21 +0000 (UTC) X-FDA: 77939157282.15.A46D307 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf24.hostedemail.com (Postfix) with ESMTP id AAA99A0009CE for ; Sat, 20 Mar 2021 05:42:20 +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=kAv7MXv8jpNwJmIUMuWQfoif0S1mOTB4TPHRFVdLxzk=; b=GW7ZF9TgRc9llamS7mC9WcwAu4 8wIMkrdsZC55pqrSQfahfqyv2WzPQaL9fuOfuRoTIddRQu07VO5c6U5f99n6SXjPyks8zzeVoNZna 2XhlhtJTUv6ncbl53AJ56VALVj0DVyIYzOiUrLftQJ1DshVohfetNR6gWP0NuX2hYlkWcKHg8PvHU HZrioCV2vW5VOF9H/I4deAYItEmyf/norWgauIMUa2aFMlZB3Pi6r43EB5pOFnr0HrdCcpDbmjRA0 3uhOeLWPUkPgXHysVrRGgf2Deifu4Km3u7e10D0yHl6fh2Oeq1/P1Va4U0ugmAB8LxffJmL+nNFEm lua7Q65g==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lNUNA-005SVj-8T; Sat, 20 Mar 2021 05:42:05 +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, Zi Yan Subject: [PATCH v5 08/27] mm: Add put_folio Date: Sat, 20 Mar 2021 05:40:45 +0000 Message-Id: <20210320054104.1300774-9-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-Stat-Signature: eekgf1hourm8ogniqwdtscfxs749fqpf X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: AAA99A0009CE Received-SPF: none (infradead.org>: No applicable sender policy available) receiver=imf24; identity=mailfrom; envelope-from=""; helo=casper.infradead.org; client-ip=90.155.50.34 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1616218940-48642 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 put_folio() 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 1714 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 --- include/linux/mm.h | 28 +++++++++++++++++++++++----- 1 file changed, 23 insertions(+), 5 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index e176e9c9990f..5052479febc7 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1226,9 +1226,28 @@ static inline __must_check bool try_get_page(struct page *page) return true; } +/** + * put_folio - 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 put_folio() 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 put_folio(struct folio *folio) +{ + if (put_page_testzero(&folio->page)) + __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 @@ -1236,13 +1255,12 @@ 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); + put_folio(folio); } /*