On 21.06.19 20:24, David Hildenbrand wrote:
> On 21.06.19 17:15, Qian Cai wrote:
>> On Thu, 2019-06-20 at 20:31 +0200, David Hildenbrand wrote:
>>> @Andrew: Only patch 1, 4 and 6 changed compared to v1.
>>>
>>> Some further cleanups around memory block devices. Especially, clean up
>>> and simplify walk_memory_range(). Including some other minor cleanups.
>>>
>>> Compiled + tested on x86 with DIMMs under QEMU. Compile-tested on ppc64.
>>>
>>> v2 -> v3:
>>> - "mm/memory_hotplug: Rename walk_memory_range() and pass start+size .."
>>> -- Avoid warning on ppc.
>>> - "drivers/base/memory.c: Get rid of find_memory_block_hinted()"
>>> -- Fixup a comment regarding hinted devices.
>>>
>>> v1 -> v2:
>>> - "mm: Section numbers use the type "unsigned long""
>>> -- "unsigned long i" -> "unsigned long nr", in one case -> "int i"
>>> - "drivers/base/memory.c: Get rid of find_memory_block_hinted("
>>> -- Fix compilation error
>>> -- Get rid of the "hint" parameter completely
>>>
>>> David Hildenbrand (6):
>>> mm: Section numbers use the type "unsigned long"
>>> drivers/base/memory: Use "unsigned long" for block ids
>>> mm: Make register_mem_sect_under_node() static
>>> mm/memory_hotplug: Rename walk_memory_range() and pass start+size
>>> instead of pfns
>>> mm/memory_hotplug: Move and simplify walk_memory_blocks()
>>> drivers/base/memory.c: Get rid of find_memory_block_hinted()
>>>
>>> arch/powerpc/platforms/powernv/memtrace.c | 23 ++---
>>> drivers/acpi/acpi_memhotplug.c | 19 +---
>>> drivers/base/memory.c | 120 +++++++++++++---------
>>> drivers/base/node.c | 8 +-
>>> include/linux/memory.h | 5 +-
>>> include/linux/memory_hotplug.h | 2 -
>>> include/linux/mmzone.h | 4 +-
>>> include/linux/node.h | 7 --
>>> mm/memory_hotplug.c | 57 +---------
>>> mm/sparse.c | 12 +--
>>> 10 files changed, 106 insertions(+), 151 deletions(-)
>>>
>>
>> This series causes a few machines are unable to boot triggering endless soft
>> lockups. Reverted those commits fixed the issue.
>>
>> 97f4217d1da0 Revert "mm/memory_hotplug: rename walk_memory_range() and pass
>> start+size instead of pfns"
>> c608eebf33c6 Revert "mm-memory_hotplug-rename-walk_memory_range-and-pass-
>> startsize-instead-of-pfns-fix"
>> 34b5e4ab7558 Revert "mm/memory_hotplug: move and simplify walk_memory_blocks()"
>> 59a9f3eec5d1 Revert "drivers/base/memory.c: Get rid of
>> find_memory_block_hinted()"
>> 5cfcd52288b6 Revert "drivers-base-memoryc-get-rid-of-find_memory_block_hinted-
>> v3"
>>
>> [ 4.582081][ T1] ACPI FADT declares the system doesn't support PCIe ASPM,
>> so disable it
>> [ 4.590405][ T1] ACPI: bus type PCI registered
>> [ 4.592908][ T1] PCI: MMCONFIG for domain 0000 [bus 00-ff] at [mem
>> 0x80000000-0x8fffffff] (base 0x80000000)
>> [ 4.601860][ T1] PCI: MMCONFIG at [mem 0x80000000-0x8fffffff] reserved in
>> E820
>> [ 4.601860][ T1] PCI: Using configuration type 1 for base access
>> [ 28.661336][ C16] watchdog: BUG: soft lockup - CPU#16 stuck for 22s!
>> [swapper/0:1]
>> [ 28.671351][ C16] Modules linked in:
>> [ 28.671354][ C16] CPU: 16 PID: 1 Comm: swapper/0 Not tainted 5.2.0-rc5-
>> next-20190621+ #1
>> [ 28.681366][ C16] Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385
>> Gen10, BIOS A40 03/09/2018
>> [ 28.691334][ C16] RIP: 0010:_raw_spin_unlock_irqrestore+0x2f/0x40
>> [ 28.701334][ C16] Code: 55 48 89 e5 41 54 49 89 f4 be 01 00 00 00 53 48 8b
>> 55 08 48 89 fb 48 8d 7f 18 e8 4c 89 7d ff 48 89 df e8 94 f9 7d ff 41 54 9d <65>
>> ff 0d c2 44 8d 48 5b 41 5c 5d c3 0f 1f 44 00 00 0f 1f 44 00 00
>> [ 28.711354][ C16] RSP: 0018:ffff888205b27bf8 EFLAGS: 00000246 ORIG_RAX:
>> ffffffffffffff13
>> [ 28.721372][ C16] RAX: 0000000000000000 RBX: ffff8882053d6138 RCX:
>> ffffffffb6f2a3b8
>> [ 28.731371][ C16] RDX: 1ffff11040a7ac27 RSI: dffffc0000000000 RDI:
>> ffff8882053d6138
>> [ 28.741371][ C16] RBP: ffff888205b27c08 R08: ffffed1040a7ac28 R09:
>> ffffed1040a7ac27
>> [ 28.751334][ C16] R10: ffffed1040a7ac27 R11: ffff8882053d613b R12:
>> 0000000000000246
>> [ 28.751370][ C16] R13: ffff888205b27c98 R14: ffff8884504d0a20 R15:
>> 0000000000000000
>> [ 28.761368][ C16] FS: 0000000000000000(0000) GS:ffff888454500000(0000)
>> knlGS:0000000000000000
>> [ 28.771373][ C16] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [ 28.781334][ C16] CR2: 0000000000000000 CR3: 00000007c9012000 CR4:
>> 00000000001406a0
>> [ 28.791333][ C16] Call Trace:
>> [ 28.791374][ C16] klist_next+0xd8/0x1c0
>> [ 28.791374][ C16] subsys_find_device_by_id+0x13b/0x1f0
>> [ 28.801334][ C16] ? bus_find_device_by_name+0x20/0x20
>> [ 28.801370][ C16] ? kobject_put+0x23/0x250
>> [ 28.811333][ C16] walk_memory_blocks+0x6c/0xb8
>> [ 28.811353][ C16] ? write_policy_show+0x40/0x40
>> [ 28.821334][ C16] link_mem_sections+0x7e/0xa0
>> [ 28.821369][ C16] ? unregister_memory_block_under_nodes+0x210/0x210
>> [ 28.831353][ C16] ? __register_one_node+0x3bd/0x600
>> [ 28.831353][ C16] topology_init+0xbf/0x126
>> [ 28.841364][ C16] ? enable_cpu0_hotplug+0x1a/0x1a
>> [ 28.841368][ C16] do_one_initcall+0xfe/0x45a
>> [ 28.851334][ C16] ? initcall_blacklisted+0x150/0x150
>> [ 28.851353][ C16] ? kasan_check_write+0x14/0x20
>> [ 28.861333][ C16] ? up_write+0x75/0x140
>> [ 28.861369][ C16] kernel_init_freeable+0x619/0x6ac
>> [ 28.871333][ C16] ? rest_init+0x188/0x188
>> [ 28.871353][ C16] kernel_init+0x11/0x138
>> [ 28.881363][ C16] ? rest_init+0x188/0x188
>> [ 28.881363][ C16] ret_from_fork+0x22/0x40
>> [ 56.661336][ C16] watchdog: BUG: soft lockup - CPU#16 stuck for 22s!
>> [swapper/0:1]
>> [ 56.671352][ C16] Modules linked in:
>> [ 56.671354][ C16] CPU: 16 PID: 1 Comm: swapper/0 Tainted:
>> G L 5.2.0-rc5-next-20190621+ #1
>> [ 56.681357][ C16] Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385
>> Gen10, BIOS A40 03/09/2018
>> [ 56.691356][ C16] RIP: 0010:subsys_find_device_by_id+0x168/0x1f0
>> [ 56.701334][ C16] Code: 48 85 c0 74 3e 48 8d 78 58 e8 14 77 ca ff 4d 8b 7e
>> 58 4d 85 ff 74 2c 49 8d bf a0 03 00 00 e8 bf 75 ca ff 45 39 a7 a0 03 00 00 <75>
>> c9 4c 89 ff e8 0e 89 ff ff 48 85 c0 74 bc 48 89 df e8 21 3b 24
>> [ 56.721333][ C16] RSP: 0018:ffff888205b27c68 EFLAGS: 00000287 ORIG_RAX:
>> ffffffffffffff13
>> [ 56.721370][ C16] RAX: 0000000000000000 RBX: ffff888205b27c90 RCX:
>> ffffffffb74c9dc1
>> [ 56.731370][ C16] RDX: 0000000000000003 RSI: dffffc0000000000 RDI:
>> ffff8888774ec3e0
>> [ 56.741371][ C16] RBP: ffff888205b27cf8 R08: ffffed1040a7ac28 R09:
>> ffffed1040a7ac27
>> [ 56.751335][ C16] R10: ffffed1040a7ac27 R11: ffff8882053d613b R12:
>> 0000000000085c1b
>> [ 56.761334][ C16] R13: 1ffff11040b64f8e R14: ffff888450de4a20 R15:
>> ffff8888774ec040
>> [ 56.761372][ C16] FS: 0000000000000000(0000) GS:ffff888454500000(0000)
>> knlGS:0000000000000000
>> [ 56.771374][ C16] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [ 56.781370][ C16] CR2: 0000000000000000 CR3: 00000007c9012000 CR4:
>> 00000000001406a0
>> [ 56.791373][ C16] Call Trace:
>> [ 56.791373][ C16] ? bus_find_device_by_name+0x20/0x20
>> [ 56.801334][ C16] ? kobject_put+0x23/0x250
>> [ 56.801334][ C16] walk_memory_blocks+0x6c/0xb8
>> [ 56.811333][ C16] ? write_policy_show+0x40/0x40
>> [ 56.811353][ C16] link_mem_sections+0x7e/0xa0
>> [ 56.811353][ C16] ? unregister_memory_block_under_nodes+0x210/0x210
>> [ 56.821333][ C16] ? __register_one_node+0x3bd/0x600
>> [ 56.831333][ C16] topology_init+0xbf/0x126
>> [ 56.831355][ C16] ? enable_cpu0_hotplug+0x1a/0x1a
>> [ 56.841334][ C16] do_one_initcall+0xfe/0x45a
>> [ 56.841334][ C16] ? initcall_blacklisted+0x150/0x150
>> [ 56.851333][ C16] ? kasan_check_write+0x14/0x20
>> [ 56.851354][ C16] ? up_write+0x75/0x140
>> [ 56.861333][ C16] kernel_init_freeable+0x619/0x6ac
>> [ 56.861333][ C16] ? rest_init+0x188/0x188
>> [ 56.861369][ C16] kernel_init+0x11/0x138
>> [ 56.871333][ C16] ? rest_init+0x188/0x188
>> [ 56.871354][ C16] ret_from_fork+0x22/0x40
>> [ 64.601362][ C16] rcu: INFO: rcu_sched self-detected stall on CPU
>> [ 64.611335][ C16] rcu: 16-....: (5958 ticks this GP)
>> idle=37e/1/0x4000000000000002 softirq=27/27 fqs=3000
>> [ 64.621334][ C16] (t=6002 jiffies g=-1079 q=25)
>> [ 64.621334][ C16] NMI backtrace for cpu 16
>> [ 64.621374][ C16] CPU: 16 PID: 1 Comm: swapper/0 Tainted:
>> G L 5.2.0-rc5-next-20190621+ #1
>> [ 64.631372][ C16] Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385
>> Gen10, BIOS A40 03/09/2018
>> [ 64.641371][ C16] Call Trace:
>> [ 64.651337][ C16] <IRQ>
>> [ 64.651376][ C16] dump_stack+0x62/0x9a
>> [ 64.651376][ C16] nmi_cpu_backtrace.cold.0+0x2e/0x33
>> [ 64.661337][ C16] ? nmi_cpu_backtrace_handler+0x20/0x20
>> [ 64.661337][ C16] nmi_trigger_cpumask_backtrace+0x1a6/0x1b9
>> [ 64.671353][ C16] arch_trigger_cpumask_backtrace+0x19/0x20
>> [ 64.681366][ C16] rcu_dump_cpu_stacks+0x18b/0x1d6
>> [ 64.681366][ C16] rcu_sched_clock_irq.cold.64+0x368/0x791
>> [ 64.691336][ C16] ? kasan_check_read+0x11/0x20
>> [ 64.691354][ C16] ? __raise_softirq_irqoff+0x66/0x150
>> [ 64.701336][ C16] update_process_times+0x2f/0x60
>> [ 64.701362][ C16] tick_periodic+0x38/0xe0
>> [ 64.711334][ C16] tick_handle_periodic+0x2e/0x80
>> [ 64.711353][ C16] smp_apic_timer_interrupt+0xfb/0x370
>> [ 64.721367][ C16] apic_timer_interrupt+0xf/0x20
>> [ 64.721367][ C16] </IRQ>
>> [ 64.721367][ C16] RIP: 0010:_raw_spin_unlock_irqrestore+0x2f/0x40
>> [ 64.731370][ C16] Code: 55 48 89 e5 41 54 49 89 f4 be 01 00 00 00 53
>>
>
> @Qian Cai, unfortunately I can't reproduce.
>
> If you get the chance, it would be great if you could retry with
>
> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> index 972c5336bebf..742f99ddd148 100644
> --- a/drivers/base/memory.c
> +++ b/drivers/base/memory.c
> @@ -868,6 +868,9 @@ int walk_memory_blocks(unsigned long start, unsigned
> long size,
> unsigned long block_id;
> int ret = 0;
>
> + if (!size)
> + return;
> +
> for (block_id = start_block_id; block_id <= end_block_id;
> block_id++) {
> mem = find_memory_block_by_id(block_id);
> if (!mem)
>
>
>
> If both, start and size are 0, we would get a veeeery long loop. This
> would mean that we have an online node that does not span any pages at
> all (pgdat->node_start_pfn = 0, start_pfn + pgdat->node_spanned_pages = 0).
>
...trying to reproduce with QEMU (setting 0MB for the second node):
qemu-system-x86_64 --enable-kvm -m 4G,maxmem=20G,slots=2 \
-smp sockets=2,cores=1 \
-numa node,nodeid=0,cpus=0,mem=4G \
-numa node,nodeid=1,cpus=1,mem=0 ...
I can indeed see that the node is online and
"pgdat->node_start_pfn == 0 && start_pfn + pgdat->node_spanned_pages == 0".
However, the kernel segfaults in an unrelated code path, so I can't
verify if this solves this problem:
[ 0.313284] BUG: kernel NULL pointer dereference, address: 00000000000000a0
[ 0.313479] #PF: supervisor read access in kernel mode
[ 0.313479] #PF: error_code(0x0000) - not-present page
[ 0.313479] PGD 0 P4D 0
[ 0.313479] Oops: 0000 [#1] SMP PTI
[ 0.313479] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.2.0-rc5-next-20190620+ #56
[ 0.313479] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.4
[ 0.313479] RIP: 0010:bus_add_device+0x59/0x110
[ 0.313479] Code: 20 48 89 df e8 f8 b4 ff ff 41 89 c4 85 c0 0f 85 81 00 00 00 48 8b 53 50 48 85 d2 75 03 48 8b 135
[ 0.313479] RSP: 0000:ffffb4a6c0013e20 EFLAGS: 00010246
[ 0.313479] RAX: 0000000000000000 RBX: ffff8b61bac23800 RCX: 0000000000000000
[ 0.313479] RDX: ffff8b61bac29038 RSI: ffff8b61bac23800 RDI: ffff8b61bac23800
[ 0.313479] RBP: ffffffff9d2f4500 R08: 0000000000000000 R09: 0000000000000001
[ 0.313479] R10: 0000000000000000 R11: ffff8b61bad20878 R12: 0000000000000000
[ 0.313479] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[ 0.313479] FS: 0000000000000000(0000) GS:ffff8b61bba00000(0000) knlGS:0000000000000000
[ 0.313479] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 0.313479] CR2: 00000000000000a0 CR3: 0000000013c24000 CR4: 00000000000006f0
[ 0.313479] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 0.313479] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 0.313479] Call Trace:
[ 0.313479] device_add+0x304/0x660
[ 0.313479] ? __init_waitqueue_head+0x31/0x50
[ 0.313479] __register_one_node+0x67/0x170
[ 0.313479] __try_online_node.cold+0x3e/0x78
[ 0.313479] try_online_node+0x25/0x40
[ 0.313479] do_cpu_up+0x36/0xc0
[ 0.313479] smp_init+0x59/0xb3
[ 0.313479] kernel_init_freeable+0x11a/0x247
[ 0.313479] ? rest_init+0x23f/0x23f
[ 0.313479] kernel_init+0x5/0xf1
[ 0.313479] ret_from_fork+0x3a/0x50
[ 0.313479] Modules linked in:
Figuring out what goes wrong here (maybe QEMU creating a weird
system configuration) is a different journey :)
--
Thanks,
David / dhildenb
