| Message ID | 1389380698-19361-3-git-send-email-prarit@redhat.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Fri, 2014-01-10 at 14:04 -0500, Prarit Bhargava wrote: : > --- > Documentation/kernel-parameters.txt | 3 +++ > drivers/acpi/acpi_memhotplug.c | 12 ++++++++++++ > 2 files changed, 15 insertions(+) > > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > index b9e9bd8..41374f9 100644 > --- a/Documentation/kernel-parameters.txt > +++ b/Documentation/kernel-parameters.txt > @@ -2117,6 +2117,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. > > nomce [X86-32] Machine Check Exception > > + acpi_no_memhotplug [ACPI] Disable memory hotplug. Useful for kexec > + and kdump kernels. > + Please move it to where other acpi_xxx are described. For kdump kernel, this option will be used when memmap=exactmap is deprecated. IOW, it is not useful yet. Not sure what you mean by kexec kernel. Memory hotplug does not need to be disabled for kexec reboot. Thanks, -Toshi -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index b9e9bd8..41374f9 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2117,6 +2117,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. nomce [X86-32] Machine Check Exception + acpi_no_memhotplug [ACPI] Disable memory hotplug. Useful for kexec + and kdump kernels. + nomfgpt [X86-32] Disable Multi-Function General Purpose Timer usage (for AMD Geode machines). diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c index 551dad7..4a0fa94 100644 --- a/drivers/acpi/acpi_memhotplug.c +++ b/drivers/acpi/acpi_memhotplug.c @@ -361,7 +361,19 @@ static void acpi_memory_device_remove(struct acpi_device *device) acpi_memory_device_free(mem_device); } +static bool acpi_no_memhotplug; + 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) +{ + acpi_no_memhotplug = true; + return 1; +} +__setup("acpi_no_memhotplug", disable_acpi_memory_hotplug);
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 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. [v2]: changed acpi_no_memhotplug to bool 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 +++ drivers/acpi/acpi_memhotplug.c | 12 ++++++++++++ 2 files changed, 15 insertions(+)