From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f199.google.com (mail-wr0-f199.google.com [209.85.128.199]) by kanga.kvack.org (Postfix) with ESMTP id ACBE06B0033 for ; Wed, 29 Nov 2017 11:04:49 -0500 (EST) Received: by mail-wr0-f199.google.com with SMTP id j4so2240947wrg.15 for ; Wed, 29 Nov 2017 08:04:49 -0800 (PST) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id w12si1966925edb.141.2017.11.29.08.04.48 for (version=TLS1 cipher=AES128-SHA bits=128/128); Wed, 29 Nov 2017 08:04:48 -0800 (PST) Date: Wed, 29 Nov 2017 17:04:46 +0100 From: Michal Hocko Subject: Re: [PATCH resend] mm/page_alloc: fix comment is __get_free_pages Message-ID: <20171129160446.jluzpv3n6mjc3fwv@dhcp22.suse.cz> References: <1511780964-64864-1-git-send-email-chenjiankang1@huawei.com> <20171127113341.ldx32qvexqe2224d@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171127113341.ldx32qvexqe2224d@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: JianKang Chen Cc: akpm@linux-foundation.org, mgorman@techsingularity.net, hannes@cmpxchg.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, xieyisheng1@huawei.com, guohanjun@huawei.com, wangkefeng.wang@huawei.com On Mon 27-11-17 12:33:41, Michal Hocko wrote: > On Mon 27-11-17 19:09:24, JianKang Chen wrote: > > From: Jiankang Chen > > > > __get_free_pages will return an virtual address, > > but it is not just 32-bit address, for example a 64-bit system. > > And this comment really confuse new bigenner of mm. > > s@bigenner@beginner@ > > Anyway, do we really need a bug on for this? Has this actually caught > any wrong usage? VM_BUG_ON tends to be enabled these days AFAIK and > panicking the kernel seems like an over-reaction. If there is a real > risk then why don't we simply mask __GFP_HIGHMEM off when calling > alloc_pages? I meant this ---