From patchwork Fri Apr 30 18:07:15 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12233975 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=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 B6981C433ED for ; Fri, 30 Apr 2021 18:13:43 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2D3376146D for ; Fri, 30 Apr 2021 18:13:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2D3376146D 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 A88326B006C; Fri, 30 Apr 2021 14:13:42 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A5EEA6B006E; Fri, 30 Apr 2021 14:13:42 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 94DFE6B0070; Fri, 30 Apr 2021 14:13:42 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0096.hostedemail.com [216.40.44.96]) by kanga.kvack.org (Postfix) with ESMTP id 7C7836B006C for ; Fri, 30 Apr 2021 14:13:42 -0400 (EDT) Received: from smtpin37.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 39450181AF5C2 for ; Fri, 30 Apr 2021 18:13:42 +0000 (UTC) X-FDA: 78089831484.37.E081606 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf22.hostedemail.com (Postfix) with ESMTP id 11274C0007ED for ; Fri, 30 Apr 2021 18:13:34 +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=db+PTL9EAtXLFkws4aJ1HfijoiuB9GF9rbs4PdOnE3Q=; b=mvmC4xFs1ZPJ5x0fnYXrSIN+Jx 4/FDLjBfvGvEM5rFiwt3pOBt3vxCgFJ5DaILeocaqGmKoY/n3LyeipbzVnyC9p3XtxfRscHFUIePs bAp5dn8XbsVvhufZ6yqsQ2QB5gEsvAEb32LZ3QDIh9YkLAMsuXXY0Kx3CAUrSNoEPiuSZMGfk2EJC SXJ/i5bdguQRS96xdn+MT1JKDEA4JAacevN3JxWv4pbKrPeRfrcuYjCjhzUkRhRPVCJ1pPmYp0adL Pi4r4ABfIia/9CHTM8n8qAwu6SRjdDQxySZMGyxAqU2G4zxKJYbp02rHr+N2HG0U5kj8hU5h6r3q/ cY32UKng==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lcXc9-00BMYq-FC; Fri, 30 Apr 2021 18:12:05 +0000 From: "Matthew Wilcox (Oracle)" To: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, akpm@linux-foundation.org Cc: "Matthew Wilcox (Oracle)" , Zi Yan , Christoph Hellwig , Jeff Layton Subject: [PATCH v8 06/31] mm: Add folio_put Date: Fri, 30 Apr 2021 19:07:15 +0100 Message-Id: <20210430180740.2707166-7-willy@infradead.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210430180740.2707166-1-willy@infradead.org> References: <20210430180740.2707166-1-willy@infradead.org> MIME-Version: 1.0 X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 11274C0007ED Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=mvmC4xFs; dmarc=none; spf=none (imf22.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: n9prwpr6bzsmmhio1wptspeotbjxuxs7 Received-SPF: none (infradead.org>: No applicable sender policy available) receiver=imf22; identity=mailfrom; envelope-from=""; helo=casper.infradead.org; client-ip=90.155.50.34 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1619806414-162824 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 1312 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 --- 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 a55c2c0628b6..610948f0cb43 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. @@ -1242,9 +1247,28 @@ 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 @@ -1252,13 +1276,12 @@ 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); } /*