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,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 974B8C433E0 for ; Fri, 5 Mar 2021 04:19:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5845F65009 for ; Fri, 5 Mar 2021 04:19:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229957AbhCEETr (ORCPT ); Thu, 4 Mar 2021 23:19:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44836 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229437AbhCEETr (ORCPT ); Thu, 4 Mar 2021 23:19:47 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2236AC061574; Thu, 4 Mar 2021 20:19:47 -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=d50BWWwyptEXh1B6An6n9AJNYi6qLn96OD0apF8yUVA=; b=ALmZiyAevE8ylgfKYrhR8VnqUL QIi7RhfS1Wv9c79tU1+Sda1hU6HUss0VHmRBPZTvQXfdaQXsQ0uTkXWnh+GR3mIdBqgucMiAqRO+S LkF6HBqm6gRgivRU3VGTXzO7R2LDruxqLqgmC/gHrnhNkCTSCUcmqW+gg84DSoVatxqDag/7eYIln zOHhrTLzwwZge5IE4I2XesegOaIDj/eBnR1MsT3USqjDB198Sr+eNOwrFMLQMybPq9ZNSpaUAf5FI P/JqEuT7x6zYrh7OIO3nw42N9lOa2BjBDpocerIyHMjdQ/LO6SO4sXDeCFtuT4Ad+pEio5CF8O7iF V7Ay+uqg==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lI1vx-00A3TP-GY; Fri, 05 Mar 2021 04:19:26 +0000 From: "Matthew Wilcox (Oracle)" To: linux-mm@kvack.org Cc: "Matthew Wilcox (Oracle)" , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Zi Yan Subject: [PATCH v4 06/25] mm: Add get_folio Date: Fri, 5 Mar 2021 04:18:42 +0000 Message-Id: <20210305041901.2396498-7-willy@infradead.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210305041901.2396498-1-willy@infradead.org> References: <20210305041901.2396498-1-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) Reviewed-by: Zi Yan --- 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 30fd431b1b05..4595955805f8 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1177,18 +1177,19 @@ 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); -- 2.30.0