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 5751CC433ED for ; Fri, 9 Apr 2021 18:58:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3016461074 for ; Fri, 9 Apr 2021 18:58:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234821AbhDIS6R (ORCPT ); Fri, 9 Apr 2021 14:58:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59652 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234705AbhDIS6Q (ORCPT ); Fri, 9 Apr 2021 14:58:16 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 93501C061762; Fri, 9 Apr 2021 11:58:03 -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=W5g+VwHltNTj8FpdbjCM8nUwZBIK09QAEf3IQR2EfkI=; b=FJcUD5OWaQ1F07avMpHBfY5M8P Dq9vUamNO9uOBi0OqHdFa5M2xUIlujch1gP4Sq18agRZ4fX6IET6hmXf5j6GgyKsQjUR8IKsxMd5t EaDtTeyd6YmXiw3NF9S+LxAwEPWD/AL+08HNy+h6+BxsoT+MnqnTqTeqIQ63KsR+f5ZlDdkdInC/2 70NEC6n+CGkiLiUASJbTwLcvZ7IVLlY+YOM+tGQ+6TJ3hNXjPyNeuoIJJKPyn1fRCG/1r3OnTIZ9Y gT1c1jbBo8HsZVPKkJKQg8OtRsTEVFx+Z6NWteWLjNbmuWV60+Sfa2510Gievcvh2M9mWVeOlBt3d ljYiYDFA==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lUwJ1-000nZl-VF; Fri, 09 Apr 2021 18:56:52 +0000 From: "Matthew Wilcox (Oracle)" To: linux-mm@kvack.org Cc: "Matthew Wilcox (Oracle)" , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-cachefs@redhat.com, linux-afs@lists.infradead.org, Zi Yan , Christoph Hellwig , Jeff Layton Subject: [PATCH v7 08/28] mm: Add get_folio Date: Fri, 9 Apr 2021 19:50:45 +0100 Message-Id: <20210409185105.188284-9-willy@infradead.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210409185105.188284-1-willy@infradead.org> References: <20210409185105.188284-1-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 Reviewed-by: Christoph Hellwig Acked-by: Jeff Layton --- 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 747c6f47aef6..67d9104c1cc1 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1219,18 +1219,26 @@ 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) + +/** + * get_folio - 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, + * try_grab_page() may be the right interface for you to use. + */ +static inline void get_folio(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); + get_folio(page_folio(page)); } bool __must_check try_grab_page(struct page *page, unsigned int flags); -- 2.30.2