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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 6BE9AC43331 for ; Thu, 2 Apr 2020 04:09:59 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2F0472074D for ; Thu, 2 Apr 2020 04:09:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="XSnjPkaI" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2F0472074D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id D3F258E0076; Thu, 2 Apr 2020 00:09:58 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CEEA38E000D; Thu, 2 Apr 2020 00:09:58 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B67BE8E0076; Thu, 2 Apr 2020 00:09:58 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0200.hostedemail.com [216.40.44.200]) by kanga.kvack.org (Postfix) with ESMTP id 974448E000D for ; Thu, 2 Apr 2020 00:09:58 -0400 (EDT) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 54C75180AD807 for ; Thu, 2 Apr 2020 04:09:58 +0000 (UTC) X-FDA: 76661586876.07.cream96_57067f2c70544 X-HE-Tag: cream96_57067f2c70544 X-Filterd-Recvd-Size: 3600 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf26.hostedemail.com (Postfix) with ESMTP for ; Thu, 2 Apr 2020 04:09:57 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E2506208E0; Thu, 2 Apr 2020 04:09:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585800597; bh=mtAOIYI6a8O6xeb4LIjrLwooojzZ52e1nVxPeq5/iGs=; h=Date:From:To:Subject:In-Reply-To:From; b=XSnjPkaIJF165cHn+T9BU9ImnQYZjngGXGtzRp3veKMqKufiBB1Pm7a1TUdNs4VNe AybLgl9dlPCxme/NN+rqhgcjRSmtEAYsEYINYQbrDQPMS0kXrnqyOfhb23a8/TKr8C e8tMmhQaT1di9bb5FDmaUXHRsia7LNa04QKhMV80= Date: Wed, 01 Apr 2020 21:09:56 -0700 From: Andrew Morton To: akpm@linux-foundation.org, alexander.h.duyck@linux.intel.com, chenqiwu@xiaomi.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, pankaj.gupta.linux@gmail.com, torvalds@linux-foundation.org, vbabka@suse.cz, willy@infradead.org Subject: [patch 118/155] mm/page_alloc: simplify page_is_buddy() for better code readability Message-ID: <20200402040956.IYrzeYzCM%akpm@linux-foundation.org> In-Reply-To: <20200401210155.09e3b9742e1c6e732f5a7250@linux-foundation.org> User-Agent: s-nail v14.8.16 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: From: chenqiwu Subject: mm/page_alloc: simplify page_is_buddy() for better code readability Simplify page_is_buddy() to reduce the redundant code for better code readability. Link: http://lkml.kernel.org/r/1583853751-5525-1-git-send-email-qiwuchen55@gmail.com Signed-off-by: chenqiwu Reviewed-by: Alexander Duyck Reviewed-by: Matthew Wilcox (Oracle) Reviewed-by: Vlastimil Babka Acked-by: Pankaj Gupta Signed-off-by: Andrew Morton --- mm/page_alloc.c | 33 +++++++++++++-------------------- 1 file changed, 13 insertions(+), 20 deletions(-) --- a/mm/page_alloc.c~mm-page_alloc-simplify-page_is_buddy-for-better-code-readability +++ a/mm/page_alloc.c @@ -792,32 +792,25 @@ static inline void set_page_order(struct * * For recording page's order, we use page_private(page). */ -static inline int page_is_buddy(struct page *page, struct page *buddy, +static inline bool page_is_buddy(struct page *page, struct page *buddy, unsigned int order) { - if (page_is_guard(buddy) && page_order(buddy) == order) { - if (page_zone_id(page) != page_zone_id(buddy)) - return 0; + if (!page_is_guard(buddy) && !PageBuddy(buddy)) + return false; - VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy); + if (page_order(buddy) != order) + return false; - return 1; - } + /* + * zone check is done late to avoid uselessly calculating + * zone/node ids for pages that could never merge. + */ + if (page_zone_id(page) != page_zone_id(buddy)) + return false; - if (PageBuddy(buddy) && page_order(buddy) == order) { - /* - * zone check is done late to avoid uselessly - * calculating zone/node ids for pages that could - * never merge. - */ - if (page_zone_id(page) != page_zone_id(buddy)) - return 0; + VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy); - VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy); - - return 1; - } - return 0; + return true; } #ifdef CONFIG_COMPACTION _