From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f72.google.com (mail-oi0-f72.google.com [209.85.218.72]) by kanga.kvack.org (Postfix) with ESMTP id BE0CF6B5904 for ; Fri, 31 Aug 2018 17:17:58 -0400 (EDT) Received: by mail-oi0-f72.google.com with SMTP id y135-v6so12062247oie.11 for ; Fri, 31 Aug 2018 14:17:58 -0700 (PDT) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com. [148.163.158.5]) by mx.google.com with ESMTPS id w191-v6si7553295oie.353.2018.08.31.14.17.57 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 31 Aug 2018 14:17:57 -0700 (PDT) Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w7VLB8mG055619 for ; Fri, 31 Aug 2018 17:17:57 -0400 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0b-001b2d01.pphosted.com with ESMTP id 2m7bf73t7m-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Fri, 31 Aug 2018 17:17:57 -0400 Received: from localhost by e06smtp02.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 31 Aug 2018 22:17:55 +0100 Date: Sat, 1 Sep 2018 00:17:48 +0300 From: Mike Rapoport Subject: Re: [PATCH RESEND] mips: switch to NO_BOOTMEM References: <1535356775-20396-1-git-send-email-rppt@linux.vnet.ibm.com> <20180830214856.cwqyjksz36ujxydm@pburton-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180830214856.cwqyjksz36ujxydm@pburton-laptop> Message-Id: <20180831211747.GA31133@rapoport-lnx> Sender: owner-linux-mm@kvack.org List-ID: To: Paul Burton Cc: Serge Semin , Ralf Baechle , James Hogan , Huacai Chen , Michal Hocko , linux-mips@linux-mips.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Hi Paul, On Thu, Aug 30, 2018 at 02:48:57PM -0700, Paul Burton wrote: > Hi Mike, > > On Mon, Aug 27, 2018 at 10:59:35AM +0300, Mike Rapoport wrote: > > MIPS already has memblock support and all the memory is already registered > > with it. > > > > This patch replaces bootmem memory reservations with memblock ones and > > removes the bootmem initialization. > > > > Signed-off-by: Mike Rapoport > > --- > > > > arch/mips/Kconfig | 1 + > > arch/mips/kernel/setup.c | 89 +++++----------------------------- > > arch/mips/loongson64/loongson-3/numa.c | 34 ++++++------- > > arch/mips/sgi-ip27/ip27-memory.c | 11 ++--- > > 4 files changed, 33 insertions(+), 102 deletions(-) > > Thanks for working on this. Unfortunately it breaks boot for at least a > 32r6el_defconfig kernel on QEMU: > > $ qemu-system-mips64el \ > -M boston \ > -kernel arch/mips/boot/vmlinux.gz.itb \ > -serial stdio \ > -append "earlycon=uart8250,mmio32,0x17ffe000,115200 console=ttyS0,115200 debug memblock=debug mminit_loglevel=4" > [ 0.000000] Linux version 4.19.0-rc1-00008-g82d0f342eecd (pburton@pburton-laptop) (gcc version 8.1.0 (GCC)) #23 SMP Thu Aug 30 14:38:06 PDT 2018 > [ 0.000000] CPU0 revision is: 0001a900 (MIPS I6400) > [ 0.000000] FPU revision is: 20f30300 > [ 0.000000] MSA revision is: 00000300 > [ 0.000000] MIPS: machine is img,boston > [ 0.000000] Determined physical RAM map: > [ 0.000000] memory: 10000000 @ 00000000 (usable) > [ 0.000000] memory: 30000000 @ 90000000 (usable) > [ 0.000000] earlycon: uart8250 at MMIO32 0x17ffe000 (options '115200') > [ 0.000000] bootconsole [uart8250] enabled > [ 0.000000] memblock_reserve: [0x00000000-0x009a8fff] setup_arch+0x224/0x718 > [ 0.000000] memblock_reserve: [0x01360000-0x01361ca7] setup_arch+0x3d8/0x718 > [ 0.000000] Initrd not found or empty - disabling initrd > [ 0.000000] memblock_virt_alloc_try_nid: 7336 bytes align=0x40 nid=-1 from=0x00000000 max_addr=0x00000000 early_init_dt_alloc_memory_arch+0x20/0x2c > [ 0.000000] memblock_reserve: [0xbfffe340-0xbfffffe7] memblock_virt_alloc_internal+0x120/0x1ec > > > It looks like we took a TLB store exception after calling memset() with > a bogus address from memblock_virt_alloc_try_nid() or something inlined > into it. Memblock tries to allocate from the top and the resulting address ends up in the high memory. With the hunk below I was able to get to "VFS: Cannot open root device" diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c index 4114d3c..4a9b0f7 100644 --- a/arch/mips/kernel/setup.c +++ b/arch/mips/kernel/setup.c @@ -577,6 +577,8 @@ static void __init bootmem_init(void) * Reserve initrd memory if needed. */ finalize_initrd(); + + memblock_set_bottom_up(true); } #endif /* CONFIG_SGI_IP27 */ > This was with your patch applied atop the mips-next branch from [1], > which is currently at commit 35d017947401 ("MIPS: ralink: Add rt3352 > SPI_CS1 pinmux"). > > Thanks, > Paul > > [1] git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux.git > -- Sincerely yours, Mike.