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 B45D16B0010 for ; Wed, 27 Jun 2018 12:02:19 -0400 (EDT) Received: by mail-wr0-f199.google.com with SMTP id i14-v6so1552870wrq.1 for ; Wed, 27 Jun 2018 09:02:19 -0700 (PDT) Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com. [148.163.156.1]) by mx.google.com with ESMTPS id c6-v6si4163826wri.363.2018.06.27.09.02.17 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 27 Jun 2018 09:02:18 -0700 (PDT) Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w5RFxOns107215 for ; Wed, 27 Jun 2018 12:02:16 -0400 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0a-001b2d01.pphosted.com with ESMTP id 2jvcj7kpru-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 27 Jun 2018 12:02:15 -0400 Received: from localhost by e06smtp07.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 27 Jun 2018 17:02:12 +0100 Date: Wed, 27 Jun 2018 19:02:07 +0300 From: Mike Rapoport Subject: Re: why do we still need bootmem allocator? References: <20180625140754.GB29102@dhcp22.suse.cz> <20180627112655.GD4291@rapoport-lnx> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Message-Id: <20180627160206.GB19182@rapoport-lnx> Sender: owner-linux-mm@kvack.org List-ID: To: Rob Herring Cc: mhocko@kernel.org, linux-mm@kvack.org, Johannes Weiner , Andrew Morton , "open list:GENERIC INCLUDE/ASM HEADER FILES" , "linux-kernel@vger.kernel.org" On Wed, Jun 27, 2018 at 07:33:55AM -0600, Rob Herring wrote: > On Wed, Jun 27, 2018 at 5:27 AM Mike Rapoport wrote: > > > > Hi, > > > > On Mon, Jun 25, 2018 at 10:09:41AM -0600, Rob Herring wrote: > > > On Mon, Jun 25, 2018 at 8:08 AM Michal Hocko wrote: > > > > > > > > Hi, > > > > I am wondering why do we still keep mm/bootmem.c when most architectures > > > > already moved to nobootmem. Is there any fundamental reason why others > > > > cannot or this is just a matter of work? > > > > > > Just because no one has done the work. I did a couple of arches > > > recently (sh, microblaze, and h8300) mainly because I broke them with > > > some DT changes. > > > > I've tried running the current upstream on h8300 gdb simulator and it > > failed: > > It seems my patch[1] is still not applied. The maintainer said he applied it. I've applied it manually. Without it unflatten_and_copy_device_tree() fails to allocate memory. It indeed can be fixed with moving bootmem_init() before, as you've noted in the commit message. I'll try to dig deeper into it. > > [ 0.000000] BUG: Bad page state in process swapper pfn:00004 > > [ 0.000000] page:007ed080 count:0 mapcount:-128 mapping:00000000 > > index:0x0 > > [ 0.000000] flags: 0x0() > > [ 0.000000] raw: 00000000 0040bdac 0040bdac 00000000 00000000 00000002 > > ffffff7f 00000000 > > [ 0.000000] page dumped because: nonzero mapcount > > ---Type to continue, or q to quit--- > > [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.18.0-rc2+ #50 > > [ 0.000000] Stack from 00401f2c: > > [ 0.000000] 00401f2c 001116cb 007ed080 00401f40 000e20e6 00401f54 > > 0004df14 00000000 > > [ 0.000000] 007ed080 007ed000 00401f5c 0004df8c 00401f90 0004e982 > > 00000044 00401fd1 > > [ 0.000000] 007ed000 007ed000 00000000 00000004 00000008 00000000 > > 00000003 00000011 > > [ 0.000000] > > [ 0.000000] Call Trace: > > [ 0.000000] [<000e20e6>] [<0004df14>] [<0004df8c>] [<0004e982>] > > [ 0.000000] [<00051a28>] [<00001000>] [<00000100>] > > [ 0.000000] Disabling lock debugging due to kernel taint > > > > With v4.13 I was able to get to "no valid init found". > > > > I had a quick look at h8300 memory initialization and it seems it has > > starting pfn set to 0 while fdt defines memory start at 4M. > > Perhaps there's another issue. > > Rob > > [1] https://patchwork.kernel.org/patch/10290317/ > -- Sincerely yours, Mike.