From patchwork Fri Apr 30 17:22:15 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12233849 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=-16.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 50F1BC433B4 for ; Fri, 30 Apr 2021 17:29:29 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C05B1613F8 for ; Fri, 30 Apr 2021 17:29:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C05B1613F8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 3B61F6B006E; Fri, 30 Apr 2021 13:29:28 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 38BEF6B0070; Fri, 30 Apr 2021 13:29:28 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 23F6D6B0071; Fri, 30 Apr 2021 13:29:28 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0105.hostedemail.com [216.40.44.105]) by kanga.kvack.org (Postfix) with ESMTP id 074E16B006E for ; Fri, 30 Apr 2021 13:29:28 -0400 (EDT) Received: from smtpin01.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id BC7444DD9 for ; Fri, 30 Apr 2021 17:29:27 +0000 (UTC) X-FDA: 78089719974.01.5B6D7EF Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf08.hostedemail.com (Postfix) with ESMTP id 4151E80192ED for ; Fri, 30 Apr 2021 17:29:04 +0000 (UTC) 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=fkHcdJvm5A3j2Mq4YEmesA1P+0SrgKTmkDpO5wJ0zB0=; b=JJdfOfYDEwTDrL9lD5qob+aOjc ek99IN0RvDUhPNi+v+OSQ400klNEVU4Vc6o5r1448r3au3rhVEEtwnM6VR76Btj/rk8bGA6iZg8nO dzCKMa7/XdhHzHQQqHbM39nGIEadyjtXsGYdT4qnsdf+7iw2WqXHYTGkMeDbIoFX/2n7XR4Q0O2HD P6yV34ZCDw+Bbr4F4d6cuI7B73aHIEW3wYusmgSINGJPhB2aoyazN/x9O3vTYRtqZetaFgR8Oz+J6 fl7e4gvT4aa55tgeKik5wdmxatqwchMNnEBmbOurERP4xixmMMBcnbfyYesI0QrO4DverIy4hzWCz wt8xaqqw==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lcWvh-00BJV2-4Q; Fri, 30 Apr 2021 17:28:21 +0000 From: "Matthew Wilcox (Oracle)" To: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, akpm@linux-foundation.org Cc: "Matthew Wilcox (Oracle)" , Zi Yan , Christoph Hellwig , Jeff Layton Subject: [PATCH v8 07/27] mm: Add folio_get Date: Fri, 30 Apr 2021 18:22:15 +0100 Message-Id: <20210430172235.2695303-8-willy@infradead.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210430172235.2695303-1-willy@infradead.org> References: <20210430172235.2695303-1-willy@infradead.org> MIME-Version: 1.0 X-Stat-Signature: e7upbciybg3mpzuoka47wcmeubmqsziw X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 4151E80192ED Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=JJdfOfYD; spf=none (imf08.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none Received-SPF: none (infradead.org>: No applicable sender policy available) receiver=imf08; identity=mailfrom; envelope-from=""; helo=casper.infradead.org; client-ip=90.155.50.34 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1619803744-452294 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: If we know we have a folio, we can call folio_get() 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 610948f0cb43..b133734a7530 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) + +/** + * 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, + * try_grab_page() 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);