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=-18.7 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 8D10FC4361B for ; Tue, 8 Dec 2020 20:23:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6DCC223A7B for ; Tue, 8 Dec 2020 20:23:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728907AbgLHUWj (ORCPT ); Tue, 8 Dec 2020 15:22:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38100 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728458AbgLHUWh (ORCPT ); Tue, 8 Dec 2020 15:22:37 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 43C2BC0611C5; Tue, 8 Dec 2020 12:21:52 -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=Zgk3uniXZHMKVYayYIMFcPF5p6Rw4gFHSO/CHoSUCok=; b=NqZO69OQznUEUwJBcNulHAJYsw LOy/OrRJNK+7F7WWhejVoD3LMVv1Ie8o6d59//iJ9605oRObFWGJRK+bGuwK49+Rocv78u9UhML/l b7wFc9aEcvEynjrhFqfuUwLQogSxkTmslcQxgNG9WMC5uQGjRllyWU32xmIPKb9w11BI75yEApUGK DbSZ1pDpRpb6kTc4SprKCXdfDjICcEOElFQdPoluvSawqDcm7oaa3YZgdO3vH+zCSve9a+ooiSR8g yoHK2Ak4eD+y42KipwScwZQFYI+cH4qbHJzbt85qOmLuWdwFfj0hUESNFy5MfEt+Op1h8hCCy5GjJ FJxIuKhg==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kmiws-00050P-8R; Tue, 08 Dec 2020 19:46:58 +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: [RFC PATCH 03/11] mm: Add get_folio Date: Tue, 8 Dec 2020 19:46:45 +0000 Message-Id: <20201208194653.19180-4-willy@infradead.org> X-Mailer: git-send-email 2.21.3 In-Reply-To: <20201208194653.19180-1-willy@infradead.org> References: <20201208194653.19180-1-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 | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 80d38cc9561c..32ac5c14097d 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1167,15 +1167,17 @@ static inline bool is_pci_p2pdma_page(const struct page *page) #define page_ref_zero_or_close_to_overflow(page) \ ((unsigned int) page_ref_count(page) + 127u <= 127u) +static inline void get_folio(struct folio *folio) +{ + /* Getting a page requires an already elevated page->_refcount. */ + VM_BUG_ON_PAGE(page_ref_zero_or_close_to_overflow(&folio->page), + &folio->page); + 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