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=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 76F05C18E5B for ; Tue, 10 Mar 2020 15:22:39 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3D8FE215A4 for ; Tue, 10 Mar 2020 15:22:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="kJ/BXz/w" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3D8FE215A4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id CA07D6B0005; Tue, 10 Mar 2020 11:22:38 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C50806B0006; Tue, 10 Mar 2020 11:22:38 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B3EEC6B0007; Tue, 10 Mar 2020 11:22:38 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0057.hostedemail.com [216.40.44.57]) by kanga.kvack.org (Postfix) with ESMTP id 9B9F46B0005 for ; Tue, 10 Mar 2020 11:22:38 -0400 (EDT) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 5FEDB4DB2 for ; Tue, 10 Mar 2020 15:22:38 +0000 (UTC) X-FDA: 76579819596.10.light28_6e527e0ef6f3b X-HE-Tag: light28_6e527e0ef6f3b X-Filterd-Recvd-Size: 4529 Received: from mail-pf1-f195.google.com (mail-pf1-f195.google.com [209.85.210.195]) by imf27.hostedemail.com (Postfix) with ESMTP for ; Tue, 10 Mar 2020 15:22:37 +0000 (UTC) Received: by mail-pf1-f195.google.com with SMTP id b72so3061019pfb.11 for ; Tue, 10 Mar 2020 08:22:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=EY9lFreAZ3AAn+r8xmwmuCckTmy61hYRhjGqopYfRTU=; b=kJ/BXz/whpjcWl/8v9MI957RfV3m8IBe56al8QNMRheXMlJ3/MY9WR00FWowKv9tTM SCIokSay21rvOWB/FHT2AUq2eCDLWejTd4ZA0CwkzYYnu/pVjRsCxksPpLrgR6mlrYYK 1t1+S38DFtLzMdUE469bdYJMLIQsKOn2D2PNtoEZJqrIJYDkkp48TsWNwljjmZNbo+y1 HdUCqm6Z/OEd1kI5T++N4P8x4XHyopRDKVmckW4SxF/+kab7FN/MZvhRa+Su++eBC5oO 4Ck/BFF9rUkUdfAMYCWk6FHnve5k3M0CSjnPPZpD/6JLZSbCZI2H5oBH+F8vNwNBJNUG yPAw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=EY9lFreAZ3AAn+r8xmwmuCckTmy61hYRhjGqopYfRTU=; b=Yg9wk807fjYW28oRdWCU6W7D/Q9itE4hnLeKLGhl6hW1FaxRLx5jyx4oA1ujTy2Rhu +5gTYdIFitXKgPg3cYCeE8bDt+/H2ao3/yUre7wp2oeMfn0Z2G93CSydpdmCPPEBYWrR SzX8KQKdl9OrpwXWK2lA57kkENS7R4lxvGhNyoIh4KKlYfmZZHAtrlDtVtqYkpUJDfUu pcpqpboBh6AAIiRENoUYyGIJGl1wU4Qs665fKT7xdu/h8KOPiPeLORBTtoCf8ZsbV0VJ NTpoALfHOMlr+HyjYoeYvwJYvPY7Vg+G7G5Dakx0U2fD/HgCacYW9rBRv/IQBsmV9eQw igRw== X-Gm-Message-State: ANhLgQ3Z3dwOCjXSAvBdiDiWVuflKIAM3IKt/Ac2I3AsFunzBD0ArcuP b83k2AnfQbaYtbKR6PUHGCs= X-Google-Smtp-Source: ADFU+vuTFFJyAbME/SPVGH+xE0uBn9DoHNYgRhPXoEUt2I/5n+fu4sXNHBaC84CmRA4t2eUbCiGltg== X-Received: by 2002:a63:a601:: with SMTP id t1mr21702859pge.23.1583853756772; Tue, 10 Mar 2020 08:22:36 -0700 (PDT) Received: from localhost ([43.224.245.179]) by smtp.gmail.com with ESMTPSA id x2sm45938961pge.2.2020.03.10.08.22.35 (version=TLS1_2 cipher=AES128-SHA bits=128/128); Tue, 10 Mar 2020 08:22:35 -0700 (PDT) From: qiwuchen55@gmail.com To: akpm@linux-foundation.org, willy@infradead.org, vbabka@suse.cz, pankaj.gupta.linux@gmail.com, alexander.duyck@gmail.com, bhe@redhat.com Cc: linux-mm@kvack.org, chenqiwu Subject: [PATCH v4] mm/page_alloc: simplify page_is_buddy() for better code readability Date: Tue, 10 Mar 2020 23:22:31 +0800 Message-Id: <1583853751-5525-1-git-send-email-qiwuchen55@gmail.com> X-Mailer: git-send-email 1.9.1 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 Simplify page_is_buddy() to reduce the redundant code for better code readability. Signed-off-by: chenqiwu --- changes in v4: - change the return type of page_is_buddy() from int to bool. - reflow the comment into fewer lines. --- mm/page_alloc.c | 33 +++++++++++++-------------------- 1 file changed, 13 insertions(+), 20 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 3c4eb75..229fc8c 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -791,32 +791,25 @@ static inline void set_page_order(struct page *page, unsigned int order) * * 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; - - VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy); + if (!page_is_guard(buddy) && !PageBuddy(buddy)) + return false; - return 1; - } + if (page_order(buddy) != order) + 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; + /* + * 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; - 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 -- 1.9.1