Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751947AbaAMXlf (ORCPT ); Mon, 13 Jan 2014 18:41:35 -0500 Received: from mx1.redhat.com ([209.132.183.28]:60589 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751295AbaAMXlc (ORCPT ); Mon, 13 Jan 2014 18:41:32 -0500 Message-ID: <52D47999.5080905@redhat.com> Date: Mon, 13 Jan 2014 18:41:13 -0500 From: Prarit Bhargava User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.17) Gecko/20110419 Red Hat/3.1.10-1.el6_0 Thunderbird/3.1.10 MIME-Version: 1.0 To: KOSAKI Motohiro CC: LKML , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , the arch/x86 maintainers , Len Brown , "Rafael J. Wysocki" , Linn Crosetto , Pekka Enberg , Yinghai Lu , Andrew Morton , Toshi Kani , Tang Chen , Wen Congyang , Vivek Goyal , Dave Young , linux-acpi@vger.kernel.org, "linux-mm@kvack.org" Subject: Re: [PATCH] x86, acpi memory hotplug, add parameter to disable memory hotplug References: <1389650161-13292-1-git-send-email-prarit@redhat.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/13/2014 05:17 PM, KOSAKI Motohiro wrote: > On Mon, Jan 13, 2014 at 4:56 PM, 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] [] dump_stack+0x19/0x1b >> [ 2.998300] [] warn_alloc_failed+0xf0/0x160 >> [ 3.004817] [] ? >> __alloc_pages_direct_compact+0xac/0x196 >> [ 3.012594] [] __alloc_pages_nodemask+0x7ff/0xa00 >> [ 3.019692] [] vmemmap_alloc_block+0x62/0xba >> [ 3.026303] [] vmemmap_alloc_block_buf+0x15/0x3b >> [ 3.033302] [] vmemmap_populate+0xb4/0x21b >> [ 3.039718] [] sparse_mem_map_populate+0x27/0x35 >> [ 3.046717] [] sparse_add_one_section+0x7a/0x185 >> [ 3.053720] [] __add_pages+0xaf/0x240 >> [ 3.059656] [] arch_add_memory+0x59/0xd0 >> [ 3.065877] [] add_memory+0xb9/0x1b0 >> [ 3.071713] [] acpi_memory_device_add+0x18d/0x26d >> [ 3.078813] [] acpi_bus_device_attach+0x7d/0xcd >> [ 3.085719] [] acpi_ns_walk_namespace+0xc8/0x17f >> [ 3.092716] [] ? acpi_bus_type_and_status+0x90/0x90 >> [ 3.100004] [] ? acpi_bus_type_and_status+0x90/0x90 >> [ 3.107293] [] acpi_walk_namespace+0x95/0xc5 >> [ 3.113904] [] acpi_bus_scan+0x8b/0x9d >> [ 3.119933] [] acpi_scan_init+0x63/0x160 >> [ 3.126153] [] acpi_init+0x25d/0x2a6 >> [ 3.131987] [] ? acpi_sleep_proc_init+0x2a/0x2a >> [ 3.138889] [] do_one_initcall+0xe2/0x190 >> [ 3.145210] [] kernel_init_freeable+0x17c/0x207 >> [ 3.152111] [] ? do_early_param+0x88/0x88 >> [ 3.158430] [] ? rest_init+0x80/0x80 >> [ 3.164264] [] kernel_init+0xe/0x180 >> [ 3.170097] [] ret_from_fork+0x7c/0xb0 >> [ 3.176123] [] ? 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] [] __add_pages+0xaf/0x240 >> [ 3.059656] [] arch_add_memory+0x59/0xd0 >> [ 3.065877] [] add_memory+0xb9/0x1b0 >> [ 3.071713] [] acpi_memory_device_add+0x18d/0x26d >> [ 3.078813] [] acpi_bus_device_attach+0x7d/0xcd >> [ 3.085719] [] acpi_ns_walk_namespace+0xc8/0x17f >> [ 3.092716] [] ? acpi_bus_type_and_status+0x90/0x90 >> [ 3.100004] [] ? acpi_bus_type_and_status+0x90/0x90 >> [ 3.107293] [] acpi_walk_namespace+0x95/0xc5 >> [ 3.113904] [] acpi_bus_scan+0x8b/0x9d >> [ 3.119933] [] acpi_scan_init+0x63/0x160 >> [ 3.126153] [] 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 >> Cc: Thomas Gleixner >> Cc: Ingo Molnar >> Cc: "H. Peter Anvin" >> Cc: x86@kernel.org >> Cc: Len Brown >> Cc: "Rafael J. Wysocki" >> Cc: Linn Crosetto >> Cc: Pekka Enberg >> Cc: Yinghai Lu >> Cc: Andrew Morton >> Cc: Toshi Kani >> Cc: Tang Chen >> Cc: Wen Congyang >> Cc: Vivek Goyal >> Cc: kosaki.motohiro@gmail.com >> Cc: dyoung@redhat.com >> Cc: Toshi Kani >> Cc: linux-acpi@vger.kernel.org >> Cc: linux-mm@kvack.org > > I think we need a knob manually enable mem-hotplug when specify memmap. But > it is another story. > > Acked-by: KOSAKI Motohiro As mentioned, self-NAK. I have seen a system that I needed to specify memmap=exactmap & had hotplug memory. I will only keep the acpi_no_memhotplug option in the next version of the patch. 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