From mboxrd@z Thu Jan 1 00:00:00 1970 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 E5B07C433E0 for ; Mon, 18 Jan 2021 17:21:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BE9D822C9E for ; Mon, 18 Jan 2021 17:21:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2407131AbhARRVY (ORCPT ); Mon, 18 Jan 2021 12:21:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58846 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406853AbhARRDU (ORCPT ); Mon, 18 Jan 2021 12:03:20 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 07633C0613D3; Mon, 18 Jan 2021 09:02:03 -0800 (PST) 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=WgNdplJNqnnOYl1riVEoZNoIZGy5sqydAea+QriKwC8=; b=hqFOZKIykRiuK22uV9CHZGGjMy m0tgyY5WePVEghFx5I2EiG37sQNLbUaBqizPy61VXorPOeL++cg7oUPcrfUOVtTocor/3D38XFIeh HUXGVHaoWSANy3gSnCk/VN8eLgO4E79nVRG/Ky9yvxa/AqxvamuC30eJthnA2/U+wTE+norPTWVqs 9Mc6ru2SySTjvVKHn25BM5JsRzyFhwT7HQhM3xDLGarAwcuMtbsVrWOb9mOVdjDFDCV7KMiZv6BFb FE9Kzu5XIIkoXfzQDLZk9y+vJxNh4esUJC7lDSLgh84dKb7YiyTUhtOLiNXfvvZ5pOzv8n9PPmIJu IVgK53vA==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1l1Xuh-00D7IS-TP; Mon, 18 Jan 2021 17:02:00 +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 06/27] mm: Add get_folio Date: Mon, 18 Jan 2021 17:01:27 +0000 Message-Id: <20210118170148.3126186-7-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 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org If we know we have a folio, we can call get_folio() instead of get_page() and save the overhead of calling compound_head(). Signed-off-by: Matthew Wilcox (Oracle) --- include/linux/mm.h | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 4d135b62a2b6..380328930d6c 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1192,18 +1192,19 @@ static inline bool is_pci_p2pdma_page(const struct page *page) } /* 127: arbitrary random number, small enough to assemble well */ -#define page_ref_zero_or_close_to_overflow(page) \ - ((unsigned int) page_ref_count(page) + 127u <= 127u) +#define folio_ref_zero_or_close_to_overflow(folio) \ + ((unsigned int) page_ref_count(&folio->page) + 127u <= 127u) + +static inline void get_folio(struct folio *folio) +{ + /* Getting a page requires an already elevated page->_refcount. */ + VM_BUG_ON_FOLIO(folio_ref_zero_or_close_to_overflow(folio), folio); + page_ref_inc(&folio->page); +} static inline void get_page(struct page *page) { - page = compound_head(page); - /* - * Getting a normal page or the head of a compound page - * requires to already have an elevated page->_refcount. - */ - VM_BUG_ON_PAGE(page_ref_zero_or_close_to_overflow(page), page); - page_ref_inc(page); + get_folio(page_folio(page)); } bool __must_check try_grab_page(struct page *page, unsigned int flags); -- 2.29.2