From patchwork Mon Jun 14 20:14:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12319773 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 5D4F7C2B9F4 for ; Mon, 14 Jun 2021 20:21:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3526D61246 for ; Mon, 14 Jun 2021 20:21:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234589AbhFNUYA (ORCPT ); Mon, 14 Jun 2021 16:24:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49322 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233590AbhFNUYA (ORCPT ); Mon, 14 Jun 2021 16:24:00 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E4167C061574; Mon, 14 Jun 2021 13:21:56 -0700 (PDT) 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=aFicQgYwLxzLs95qCn8KFU0rWAYxlBkCnc3dwpPoVrg=; b=QZeAAPntMzvlHkl6rliwQoY+a5 rVT36fDM3P5PhcqbUztfSNPhqwszEC5vZLfPu0ilNCDz5u6iEL3CQozQMD+9B+Cgi0AvqXNzP6Zj5 /WR8/kswxErBtA1wyOG9vRxjTieH1NLYA+05qd0yhM3J9VtU14eceDZ3H0ZxOksjC3y0d2fxtI8Yi 5GxST8AD5lHcuqJTcGbwzpx7iNTlyGm1tL6sAFquc0A+c15VBauoTZLwBdcJobQmlvuxeRFnKNADP GVFAOvtUuRubA5Srb/aUdEjrgOiJPsUfDt7zlY2k+uPI5/pYwiRthcpSlYqc4tPOL87xkvUJIi+FP C45MtHSg==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lst3j-005nBo-8p; Mon, 14 Jun 2021 20:19:56 +0000 From: "Matthew Wilcox (Oracle)" To: akpm@linux-foundation.org Cc: "Matthew Wilcox (Oracle)" , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Zi Yan , Christoph Hellwig , Jeff Layton , "Kirill A . Shutemov" , Vlastimil Babka , William Kucharski Subject: [PATCH v11 08/33] mm: Add folio_get() Date: Mon, 14 Jun 2021 21:14:10 +0100 Message-Id: <20210614201435.1379188-9-willy@infradead.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210614201435.1379188-1-willy@infradead.org> References: <20210614201435.1379188-1-willy@infradead.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org If we know we have a folio, we can call folio_get() instead of get_page() and save the overhead of calling compound_head(). No change to generated code. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Zi Yan Reviewed-by: Christoph Hellwig Acked-by: Jeff Layton Acked-by: Kirill A. Shutemov Acked-by: Vlastimil Babka Reviewed-by: William Kucharski Reviewed-by: David Howells --- include/linux/mm.h | 26 +++++++++++++++++--------- 1 file changed, 17 insertions(+), 9 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index b68a55cc8d93..a16ea4e745a7 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1224,18 +1224,26 @@ 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) folio_ref_count(folio) + 127u <= 127u) + +/** + * folio_get - Increment the reference count on a folio. + * @folio: The folio. + * + * Context: May be called in any context, as long as you know that + * you have a refcount on the folio. If you do not already have one, + * folio_try_get() may be the right interface for you to use. + */ +static inline void folio_get(struct folio *folio) +{ + VM_BUG_ON_FOLIO(folio_ref_zero_or_close_to_overflow(folio), folio); + folio_ref_inc(folio); +} 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); + folio_get(page_folio(page)); } bool __must_check try_grab_page(struct page *page, unsigned int flags);