From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756463AbdLOU5j (ORCPT ); Fri, 15 Dec 2017 15:57:39 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:53472 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755853AbdLOU5h (ORCPT ); Fri, 15 Dec 2017 15:57:37 -0500 Date: Fri, 15 Dec 2017 12:57:35 -0800 From: Andrew Morton To: Michal Hocko Cc: JianKang Chen , 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 Subject: Re: [PATCH resend] mm/page_alloc: fix comment is __get_free_pages Message-Id: <20171215125735.1d74c7a04c05d91f27ffdbd7@linux-foundation.org> In-Reply-To: <20171215093618.GV16951@dhcp22.suse.cz> References: <1511780964-64864-1-git-send-email-chenjiankang1@huawei.com> <20171127113341.ldx32qvexqe2224d@dhcp22.suse.cz> <20171129160446.jluzpv3n6mjc3fwv@dhcp22.suse.cz> <20171129134159.c9100ea6dacad870d69929b7@linux-foundation.org> <20171130065335.zno7peunnl2zpozq@dhcp22.suse.cz> <20171130131706.0550cd28ce47aaa976f7db2a@linux-foundation.org> <20171201072414.3kc3pbvdbqbxhnfx@dhcp22.suse.cz> <20171201111845.iyoua7hhjodpuvoy@dhcp22.suse.cz> <20171214140608.GQ16951@dhcp22.suse.cz> <20171214123309.bdee142c82809f4c4ff3ce5b@linux-foundation.org> <20171215093618.GV16951@dhcp22.suse.cz> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 15 Dec 2017 10:36:18 +0100 Michal Hocko wrote: > > > > > > So do we care and I will resend the patch in that case or I just drop > > > this from my patch queue? > > > > Well.. I still think that silently accepting bad input would be bad > > practice. If we can just delete the assertion and have such a caller > > reliably blow up later on then that's good enough. > > The point is that if the caller checks for the failed allocation then > the result is a memory leak. That's if page_address(highmem page) returns NULL. I'm not sure what it returns, really - so many different implementations across so many different architectures. Oh well, it would have been nice to remove that VM_BUG_ON(). Why not just leave the code as it is now?