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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 8BE64C43381 for ; Wed, 20 Mar 2019 19:12:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5CFF32175B for ; Wed, 20 Mar 2019 19:12:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5CFF32175B 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 F2CE86B0006; Wed, 20 Mar 2019 15:12:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id ED9916B0007; Wed, 20 Mar 2019 15:12:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DEFCB6B0008; Wed, 20 Mar 2019 15:12:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-pg1-f197.google.com (mail-pg1-f197.google.com [209.85.215.197]) by kanga.kvack.org (Postfix) with ESMTP id C16476B0006 for ; Wed, 20 Mar 2019 15:12:12 -0400 (EDT) Received: by mail-pg1-f197.google.com with SMTP id 18so3547409pgx.11 for ; Wed, 20 Mar 2019 12:12:12 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:date:from:to :cc:subject:message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=20H/scAtpGgvlthV3GTo8dwpoU8jHV62n7FssLM8lOI=; b=VEHzJIfhtKEmaCdqDg6eZf0hJkD0b/7DHTeXnPAD5+B1aKZOXOd0UK+Pu1eaN+VNMn sTl0EhROaB6CTxrAS0ohiyVyTby+QhQkihooD9yarBGWaEA/ejMKg44hso3UYS56L/g+ 7x+MsMpKnZgYe4mpsDqE9/O6kH9ETQ4bMrSGORq7f7GhVjP/WhRQEzfZs2IWo3CDeIRX 6rG9XzRg+Pc/NQ3Rs+f5MKQvOeXFO4+S7fvgAoeNCJWcsG9h8QRj2jL/d5nPI9IirNda ViBXBWP/FSBldz2tgu8E7GKKtebwfacY9QuVEKw7+AivEVj3tZX9i69AqKgPE/rmj7yX U2Iw== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of akpm@linux-foundation.org designates 140.211.169.12 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org X-Gm-Message-State: APjAAAX87D+GtgzrHO9eS8woEX2mgsyPOq5KigZ/cc/N11HhhILDOlME 3PhgQ39RlxmLhEOoDCcFuN6aMRl769foMGcB5JxZ6Gam0NxTtjHTKtCmIXkAuvjZw4xL/oq+27b N0xIaIYXIjuBTPnRkn8WVxKE7ktvKYYH1DHi6U+5StnFfx/j9S26s4hbMhc+qipsk5Q== X-Received: by 2002:a63:cc0c:: with SMTP id x12mr6297956pgf.336.1553109132305; Wed, 20 Mar 2019 12:12:12 -0700 (PDT) X-Google-Smtp-Source: APXvYqxiAubJZGR8j9IqDNt6a7ZOuW41H8PNWvmEwA9YKLMRzBttCSPyGeW5iOBYbcK41svwsH9X X-Received: by 2002:a63:cc0c:: with SMTP id x12mr6297899pgf.336.1553109131433; Wed, 20 Mar 2019 12:12:11 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1553109131; cv=none; d=google.com; s=arc-20160816; b=IAnmz8ijAMzxDi79RXHfV1aBj5dIZ7fhNIXUQz4NEX6hYybh8mWNirFxy1ZEx6gofi MOnAcQEk+Do81jlhA1q4NxnEwBmahhVnteqIwm7T0iWfw2Jo5YTP1dm8/UWE4/9xdu2G UqpHhpMnPgAj0+jEnH6TyCKOz9ughHrTE5KdSFonT/mT36p0HAHY/Lxv/ZRap8Vr+5eZ 3Sdsk+C3WFJzmACiBw1yzZCiNLm8RIQ0hx5+9pEcWHh0x3rTgfzjiZRAdtnDaZbmgmEq xG3r+hQAY5lBTJ1JsyPChfCWfy9DLbYZUYxmMROJO37O2sRV/5LpTIDg62uFR+RRcpyJ mqmQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date; bh=20H/scAtpGgvlthV3GTo8dwpoU8jHV62n7FssLM8lOI=; b=QiEU+M/Xu7j4NyJx1RGvzLJsVEHK0Ex7F3/0y5UeD2Df2Uz3O8OrUaWUUGCdGRSy69 P4gEuAN+xj1jik0L0ZwPWPaf6IPnkzCw7lJkLW/u2ml7wv68EO+bp2j16xqRXDudcWFN DQRZPldEri43IJZbDxVN0XgnHt+3Odqv1/ID3xfvdwKQ5mURJF1rhbEmmiF/prwpxA9t gGOJjlMvjy/d+ruLCxwiBw5yH5JLB5r+KHYNNRl2ni8zICecKRlfQImHEyuhrf4yppaK LOhpqGg+LXySCeqIu6hCFXTTN4GNu0mndJ25Lio1M0VtYfQtOa51dtPaXh1n80dV3rmC oLsQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of akpm@linux-foundation.org designates 140.211.169.12 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id m15si2213632pgv.212.2019.03.20.12.12.11 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 20 Mar 2019 12:12:11 -0700 (PDT) Received-SPF: pass (google.com: domain of akpm@linux-foundation.org designates 140.211.169.12 as permitted sender) client-ip=140.211.169.12; Authentication-Results: mx.google.com; spf=pass (google.com: domain of akpm@linux-foundation.org designates 140.211.169.12 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org Received: from localhost.localdomain (c-73-223-200-170.hsd1.ca.comcast.net [73.223.200.170]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id D9CB24CA1; Wed, 20 Mar 2019 19:12:10 +0000 (UTC) Date: Wed, 20 Mar 2019 12:12:09 -0700 From: Andrew Morton To: Baoquan He Cc: linux-kernel@vger.kernel.org, osalvador@suse.de, mhocko@suse.com, david@redhat.com, richard.weiyang@gmail.com, rppt@linux.ibm.com, linux-mm@kvack.org Subject: Re: [PATCH] mm, memory_hotplug: Fix the wrong usage of N_HIGH_MEMORY Message-Id: <20190320121209.5cd30d7b15f299df7d97d51e@linux-foundation.org> In-Reply-To: <20190320080732.14933-1-bhe@redhat.com> References: <20190320080732.14933-1-bhe@redhat.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit 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: On Wed, 20 Mar 2019 16:07:32 +0800 Baoquan He wrote: > In function node_states_check_changes_online(), N_HIGH_MEMORY is used > to substitute ZONE_HIGHMEM directly. This is not right. N_HIGH_MEMORY > always has value '3' if CONFIG_HIGHMEM=y, while ZONE_HIGHMEM's value > is not. It depends on whether CONFIG_ZONE_DMA/CONFIG_ZONE_DMA32 are > enabled. Obviously it's not true for CONFIG_ZONE_DMA32 on 32bit system, > and CONFIG_ZONE_DMA is also optional. > > Replace it with ZONE_HIGHMEM. > > Fixes: 8efe33f40f3e ("mm/memory_hotplug.c: simplify node_states_check_changes_online") What are the runtime effects of this change? > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -712,7 +712,7 @@ static void node_states_check_changes_online(unsigned long nr_pages, > if (zone_idx(zone) <= ZONE_NORMAL && !node_state(nid, N_NORMAL_MEMORY)) > arg->status_change_nid_normal = nid; > #ifdef CONFIG_HIGHMEM > - if (zone_idx(zone) <= N_HIGH_MEMORY && !node_state(nid, N_HIGH_MEMORY)) > + if (zone_idx(zone) <= ZONE_HIGHMEM && !node_state(nid, N_HIGH_MEMORY)) > arg->status_change_nid_high = nid; > #endif > }