Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1753010AbaANBpM (ORCPT <rfc822;w@1wt.eu>);
	Mon, 13 Jan 2014 20:45:12 -0500
Received: from mx1.redhat.com ([209.132.183.28]:36336 "EHLO mx1.redhat.com"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1751924AbaANBpH (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Mon, 13 Jan 2014 20:45:07 -0500
Date: Tue, 14 Jan 2014 09:45:16 +0800
From: Dave Young <dyoung@redhat.com>
To: Prarit Bhargava <prarit@redhat.com>
Cc: linux-kernel@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
        x86@kernel.org, Len Brown <lenb@kernel.org>,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>, Linn Crosetto <linn@hp.com>,
        Pekka Enberg <penberg@kernel.org>, Yinghai Lu <yinghai@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Toshi Kani <toshi.kani@hp.com>, Tang Chen <tangchen@cn.fujitsu.com>,
        Wen Congyang <wency@cn.fujitsu.com>, Vivek Goyal <vgoyal@redhat.com>,
        kosaki.motohiro@gmail.com, linux-acpi@vger.kernel.org,
        linux-mm@kvack.org
Subject: Re: [PATCH] x86, acpi memory hotplug, add parameter to disable
 memory hotplug
Message-ID: <20140114014516.GC4327@dhcp-16-126.nay.redhat.com>
References: <1389650161-13292-1-git-send-email-prarit@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <1389650161-13292-1-git-send-email-prarit@redhat.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 01/13/14 at 04:56pm, Prarit Bhargava wrote:
> When booting a kexec/kdump kernel on a system that has specific memory hotplug
> regions the boot will fail with warnings like:
> 
> [    2.939467] swapper/0: page allocation failure: order:9, mode:0x84d0
> [    2.946564] CPU: 0 PID: 1 Comm: swapper/0 Not tainted
> 3.10.0-65.el7.x86_64 #1
> [    2.954532] Hardware name: QCI QSSC-S4R/QSSC-S4R, BIOS
> QSSC-S4R.QCI.01.00.S013.032920111005 03/29/2011
> [    2.964926]  0000000000000000 ffff8800341bd8c8 ffffffff815bcc67
> ffff8800341bd950
> [    2.973224]  ffffffff8113b1a0 ffff880036339b00 0000000000000009
> 00000000000084d0
> [    2.981523]  ffff8800341bd950 ffffffff815b87ee 0000000000000000
> 0000000000000200
> [    2.989821] Call Trace:
> [    2.992560]  [<ffffffff815bcc67>] dump_stack+0x19/0x1b
> [    2.998300]  [<ffffffff8113b1a0>] warn_alloc_failed+0xf0/0x160
> [    3.004817]  [<ffffffff815b87ee>] ?
> __alloc_pages_direct_compact+0xac/0x196
> [    3.012594]  [<ffffffff8113f14f>] __alloc_pages_nodemask+0x7ff/0xa00
> [    3.019692]  [<ffffffff815b417c>] vmemmap_alloc_block+0x62/0xba
> [    3.026303]  [<ffffffff815b41e9>] vmemmap_alloc_block_buf+0x15/0x3b
> [    3.033302]  [<ffffffff815b1ff6>] vmemmap_populate+0xb4/0x21b
> [    3.039718]  [<ffffffff815b461d>] sparse_mem_map_populate+0x27/0x35
> [    3.046717]  [<ffffffff815b400f>] sparse_add_one_section+0x7a/0x185
> [    3.053720]  [<ffffffff815a1e9f>] __add_pages+0xaf/0x240
> [    3.059656]  [<ffffffff81047359>] arch_add_memory+0x59/0xd0
> [    3.065877]  [<ffffffff815a21d9>] add_memory+0xb9/0x1b0
> [    3.071713]  [<ffffffff81333b9c>] acpi_memory_device_add+0x18d/0x26d
> [    3.078813]  [<ffffffff81309a01>] acpi_bus_device_attach+0x7d/0xcd
> [    3.085719]  [<ffffffff8132379d>] acpi_ns_walk_namespace+0xc8/0x17f
> [    3.092716]  [<ffffffff81309984>] ? acpi_bus_type_and_status+0x90/0x90
> [    3.100004]  [<ffffffff81309984>] ? acpi_bus_type_and_status+0x90/0x90
> [    3.107293]  [<ffffffff81323c8c>] acpi_walk_namespace+0x95/0xc5
> [    3.113904]  [<ffffffff8130a6d6>] acpi_bus_scan+0x8b/0x9d
> [    3.119933]  [<ffffffff81a2019a>] acpi_scan_init+0x63/0x160
> [    3.126153]  [<ffffffff81a1ffb5>] acpi_init+0x25d/0x2a6
> [    3.131987]  [<ffffffff81a1fd58>] ? acpi_sleep_proc_init+0x2a/0x2a
> [    3.138889]  [<ffffffff810020e2>] do_one_initcall+0xe2/0x190
> [    3.145210]  [<ffffffff819e20c4>] kernel_init_freeable+0x17c/0x207
> [    3.152111]  [<ffffffff819e18d0>] ? do_early_param+0x88/0x88
> [    3.158430]  [<ffffffff8159fea0>] ? rest_init+0x80/0x80
> [    3.164264]  [<ffffffff8159feae>] kernel_init+0xe/0x180
> [    3.170097]  [<ffffffff815cca2c>] ret_from_fork+0x7c/0xb0
> [    3.176123]  [<ffffffff8159fea0>] ? rest_init+0x80/0x80
> [    3.181956] Mem-Info:
> [    3.184490] Node 0 DMA per-cpu:
> [    3.188007] CPU    0: hi:    0, btch:   1 usd:   0
> [    3.193353] Node 0 DMA32 per-cpu:
> [    3.197060] CPU    0: hi:   42, btch:   7 usd:   0
> [    3.202410] active_anon:0 inactive_anon:0 isolated_anon:0
> [    3.202410]  active_file:0 inactive_file:0 isolated_file:0
> [    3.202410]  unevictable:0 dirty:0 writeback:0 unstable:0
> [    3.202410]  free:872 slab_reclaimable:13 slab_unreclaimable:1880
> [    3.202410]  mapped:0 shmem:0 pagetables:0 bounce:0
> [    3.202410]  free_cma:0
> 
> because the system has run out of memory at boot time.  This occurs
> because of the following sequence in the boot:
> 
> Main kernel boots and sets E820 map.  The second kernel is booted with a
> map generated by the kdump service using memmap= and memmap=exactmap.
> These parameters are added to the kernel parameters of the kexec/kdump
> kernel.   The kexec/kdump kernel has limited memory resources so as not
> to severely impact the main kernel.
> 
> The system then panics and the kdump/kexec kernel boots (which is a
> completely new kernel boot).  During this boot ACPI is initialized and the
> kernel (as can be seen above) traverses the ACPI namespace and finds an
> entry for a memory device to be hotadded.
> 
> ie)
> 
> [    3.053720]  [<ffffffff815a1e9f>] __add_pages+0xaf/0x240
> [    3.059656]  [<ffffffff81047359>] arch_add_memory+0x59/0xd0
> [    3.065877]  [<ffffffff815a21d9>] add_memory+0xb9/0x1b0
> [    3.071713]  [<ffffffff81333b9c>] acpi_memory_device_add+0x18d/0x26d
> [    3.078813]  [<ffffffff81309a01>] acpi_bus_device_attach+0x7d/0xcd
> [    3.085719]  [<ffffffff8132379d>] acpi_ns_walk_namespace+0xc8/0x17f
> [    3.092716]  [<ffffffff81309984>] ? acpi_bus_type_and_status+0x90/0x90
> [    3.100004]  [<ffffffff81309984>] ? acpi_bus_type_and_status+0x90/0x90
> [    3.107293]  [<ffffffff81323c8c>] acpi_walk_namespace+0x95/0xc5
> [    3.113904]  [<ffffffff8130a6d6>] acpi_bus_scan+0x8b/0x9d
> [    3.119933]  [<ffffffff81a2019a>] acpi_scan_init+0x63/0x160
> [    3.126153]  [<ffffffff81a1ffb5>] acpi_init+0x25d/0x2a6
> 
> At this point the kernel adds page table information and the the kexec/kdump
> kernel runs out of memory.
> 
> This can also be reproduced with a "regular" kernel by using the
> memmap=exactmap and mem=X parameters on the main kernel and booting.
> 
> This patchset resolves the problem by adding a kernel parameter,
> acpi_no_memhotplug, to disable ACPI memory hotplug.  ACPI memory hotplug
> should also be disabled by default when a user specified a memory mapping with
> "memmap=exactmap" or "mem=X".
> 
> Signed-off-by: Prarit Bhargava <prarit@redhat.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Cc: x86@kernel.org
> Cc: Len Brown <lenb@kernel.org>
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Cc: Linn Crosetto <linn@hp.com>
> Cc: Pekka Enberg <penberg@kernel.org>
> Cc: Yinghai Lu <yinghai@kernel.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Toshi Kani <toshi.kani@hp.com>
> Cc: Tang Chen <tangchen@cn.fujitsu.com>
> Cc: Wen Congyang <wency@cn.fujitsu.com>
> Cc: Vivek Goyal <vgoyal@redhat.com>
> Cc: kosaki.motohiro@gmail.com
> Cc: dyoung@redhat.com
> Cc: Toshi Kani <toshi.kani@hp.com>
> Cc: linux-acpi@vger.kernel.org
> Cc: linux-mm@kvack.org
> ---
>  Documentation/kernel-parameters.txt |    3 +++
>  arch/x86/kernel/e820.c              |    4 ++++
>  drivers/acpi/acpi_memhotplug.c      |   18 ++++++++++++++++++
>  include/linux/memory_hotplug.h      |    9 +++++++++
>  4 files changed, 34 insertions(+)
> 
> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
> index b9e9bd8..ea93f75 100644
> --- a/Documentation/kernel-parameters.txt
> +++ b/Documentation/kernel-parameters.txt
> @@ -343,6 +343,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
>  			no: ACPI OperationRegions are not marked as reserved,
>  			no further checks are performed.
>  
> +	acpi_no_memhotplug [ACPI] Disable memory hotplug.  Useful for kexec
> +			   and kdump kernels.
> +
>  	add_efi_memmap	[EFI; X86] Include EFI memory map in
>  			kernel's map of available physical RAM.
>  
> diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
> index 174da5f..3c431fe 100644
> --- a/arch/x86/kernel/e820.c
> +++ b/arch/x86/kernel/e820.c
> @@ -20,6 +20,7 @@
>  #include <linux/firmware-map.h>
>  #include <linux/memblock.h>
>  #include <linux/sort.h>
> +#include <linux/memory_hotplug.h>
>  
>  #include <asm/e820.h>
>  #include <asm/proto.h>
> @@ -834,6 +835,8 @@ static int __init parse_memopt(char *p)
>  		return -EINVAL;
>  	e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
>  
> +	set_acpi_no_memhotplug();
> +
>  	return 0;
>  }
>  early_param("mem", parse_memopt);
> @@ -857,6 +860,7 @@ static int __init parse_memmap_one(char *p)
>  #endif
>  		e820.nr_map = 0;
>  		userdef = 1;
> +		set_acpi_no_memhotplug();
>  		return 0;
>  	}
>  
> diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
> index 551dad7..d104a7d 100644
> --- a/drivers/acpi/acpi_memhotplug.c
> +++ b/drivers/acpi/acpi_memhotplug.c
> @@ -361,7 +361,25 @@ static void acpi_memory_device_remove(struct acpi_device *device)
>  	acpi_memory_device_free(mem_device);
>  }
>  
> +static bool acpi_no_memhotplug;
> +
> +void set_acpi_no_memhotplug(void)
> +{
> +	acpi_no_memhotplug = true;
> +	pr_info_once("ACPI: Memory Hotplug Disabled\n");
> +}
> +
>  void __init acpi_memory_hotplug_init(void)
>  {
> +	if (acpi_no_memhotplug)
> +		return;
> +
>  	acpi_scan_add_handler_with_hotplug(&memory_device_handler, "memory");
>  }
> +
> +static int __init disable_acpi_memory_hotplug(char *str)
> +{
> +	set_acpi_no_memhotplug();
> +	return 1;
> +}
> +__setup("acpi_no_memhotplug", disable_acpi_memory_hotplug);
> diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
> index 4ca3d95..3cdb6e0 100644
> --- a/include/linux/memory_hotplug.h
> +++ b/include/linux/memory_hotplug.h
> @@ -12,6 +12,15 @@ struct pglist_data;
>  struct mem_section;
>  struct memory_block;
>  
> +#ifdef CONFIG_ACPI_HOTPLUG_MEMORY
> +/* set flag to disable ACPI memory hotplug */
> +extern void set_acpi_no_memhotplug(void);
> +#else
> +static inline void set_acpi_no_memhotplug(void)
> +{
> +}
> +#endif
> +
>  #ifdef CONFIG_MEMORY_HOTPLUG
>  
>  /*
> -- 
> 1.7.9.3
> 

Acked-by: Dave Young <dyoung@redhat.com>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/