Re: system hung up when offlining CPUs
From: YASUAKI ISHIMATSU
Date: Thu Sep 07 2017 - 16:23:51 EST
Hi Mark and Christoph,
Sorry for the late reply. I appreciated that you fixed the issue on kvm environment.
But the issue still occurs on physical server.
Here ares irq information that I summarized megasas irqs from /proc/interrupts
and /proc/irq/*/smp_affinity_list on my server:
---
IRQ affinity_list IRQ_TYPE
42 0-5 IR-PCI-MSI 1048576-edge megasas
43 0-5 IR-PCI-MSI 1048577-edge megasas
44 0-5 IR-PCI-MSI 1048578-edge megasas
45 0-5 IR-PCI-MSI 1048579-edge megasas
46 0-5 IR-PCI-MSI 1048580-edge megasas
47 0-5 IR-PCI-MSI 1048581-edge megasas
48 0-5 IR-PCI-MSI 1048582-edge megasas
49 0-5 IR-PCI-MSI 1048583-edge megasas
50 0-5 IR-PCI-MSI 1048584-edge megasas
51 0-5 IR-PCI-MSI 1048585-edge megasas
52 0-5 IR-PCI-MSI 1048586-edge megasas
53 0-5 IR-PCI-MSI 1048587-edge megasas
54 0-5 IR-PCI-MSI 1048588-edge megasas
55 0-5 IR-PCI-MSI 1048589-edge megasas
56 0-5 IR-PCI-MSI 1048590-edge megasas
57 0-5 IR-PCI-MSI 1048591-edge megasas
58 0-5 IR-PCI-MSI 1048592-edge megasas
59 0-5 IR-PCI-MSI 1048593-edge megasas
60 0-5 IR-PCI-MSI 1048594-edge megasas
61 0-5 IR-PCI-MSI 1048595-edge megasas
62 0-5 IR-PCI-MSI 1048596-edge megasas
63 0-5 IR-PCI-MSI 1048597-edge megasas
64 0-5 IR-PCI-MSI 1048598-edge megasas
65 0-5 IR-PCI-MSI 1048599-edge megasas
66 24-29 IR-PCI-MSI 1048600-edge megasas
67 24-29 IR-PCI-MSI 1048601-edge megasas
68 24-29 IR-PCI-MSI 1048602-edge megasas
69 24-29 IR-PCI-MSI 1048603-edge megasas
70 24-29 IR-PCI-MSI 1048604-edge megasas
71 24-29 IR-PCI-MSI 1048605-edge megasas
72 24-29 IR-PCI-MSI 1048606-edge megasas
73 24-29 IR-PCI-MSI 1048607-edge megasas
74 24-29 IR-PCI-MSI 1048608-edge megasas
75 24-29 IR-PCI-MSI 1048609-edge megasas
76 24-29 IR-PCI-MSI 1048610-edge megasas
77 24-29 IR-PCI-MSI 1048611-edge megasas
78 24-29 IR-PCI-MSI 1048612-edge megasas
79 24-29 IR-PCI-MSI 1048613-edge megasas
80 24-29 IR-PCI-MSI 1048614-edge megasas
81 24-29 IR-PCI-MSI 1048615-edge megasas
82 24-29 IR-PCI-MSI 1048616-edge megasas
83 24-29 IR-PCI-MSI 1048617-edge megasas
84 24-29 IR-PCI-MSI 1048618-edge megasas
85 24-29 IR-PCI-MSI 1048619-edge megasas
86 24-29 IR-PCI-MSI 1048620-edge megasas
87 24-29 IR-PCI-MSI 1048621-edge megasas
88 24-29 IR-PCI-MSI 1048622-edge megasas
89 24-29 IR-PCI-MSI 1048623-edge megasas
---
In my server, IRQ#66-89 are sent to CPU#24-29. And if I offline CPU#24-29,
I/O does not work, showing the following messages.
---
[...] sd 0:2:0:0: [sda] tag#1 task abort called for scmd(ffff8820574d7560)
[...] sd 0:2:0:0: [sda] tag#1 CDB: Read(10) 28 00 0d e8 cf 78 00 00 08 00
[...] sd 0:2:0:0: task abort: FAILED scmd(ffff8820574d7560)
[...] sd 0:2:0:0: [sda] tag#0 task abort called for scmd(ffff882057426560)
[...] sd 0:2:0:0: [sda] tag#0 CDB: Write(10) 2a 00 0d 58 37 00 00 00 08 00
[...] sd 0:2:0:0: task abort: FAILED scmd(ffff882057426560)
[...] sd 0:2:0:0: target reset called for scmd(ffff8820574d7560)
[...] sd 0:2:0:0: [sda] tag#1 megasas: target reset FAILED!!
[...] sd 0:2:0:0: [sda] tag#0 Controller reset is requested due to IO timeout
[...] SCSI command pointer: (ffff882057426560) SCSI host state: 5 SCSI
[...] IO request frame:
[...]
<snip>
[...]
[...] megaraid_sas 0000:02:00.0: [ 0]waiting for 2 commands to complete for scsi0
[...] INFO: task auditd:1200 blocked for more than 120 seconds.
[...] Not tainted 4.13.0+ #15
[...] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[...] auditd D 0 1200 1 0x00000000
[...] Call Trace:
[...] __schedule+0x28d/0x890
[...] schedule+0x36/0x80
[...] io_schedule+0x16/0x40
[...] wait_on_page_bit_common+0x109/0x1c0
[...] ? page_cache_tree_insert+0xf0/0xf0
[...] __filemap_fdatawait_range+0x127/0x190
[...] ? __filemap_fdatawrite_range+0xd1/0x100
[...] file_write_and_wait_range+0x60/0xb0
[...] xfs_file_fsync+0x67/0x1d0 [xfs]
[...] vfs_fsync_range+0x3d/0xb0
[...] do_fsync+0x3d/0x70
[...] SyS_fsync+0x10/0x20
[...] entry_SYSCALL_64_fastpath+0x1a/0xa5
[...] RIP: 0033:0x7f0bd9633d2d
[...] RSP: 002b:00007f0bd751ed30 EFLAGS: 00000293 ORIG_RAX: 000000000000004a
[...] RAX: ffffffffffffffda RBX: 00005590566d0080 RCX: 00007f0bd9633d2d
[...] RDX: 00005590566d1260 RSI: 0000000000000000 RDI: 0000000000000005
[...] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000017
[...] R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
[...] R13: 00007f0bd751f9c0 R14: 00007f0bd751f700 R15: 0000000000000000
---
Thanks,
Yasuaki Ishimatsu
On 08/21/2017 09:37 AM, Marc Zyngier wrote:
> On 21/08/17 14:18, Christoph Hellwig wrote:
>> Can you try the patch below please?
>>
>> ---
>> From d5f59cb7a629de8439b318e1384660e6b56e7dd8 Mon Sep 17 00:00:00 2001
>> From: Christoph Hellwig <hch@xxxxxx>
>> Date: Mon, 21 Aug 2017 14:24:11 +0200
>> Subject: virtio_pci: fix cpu affinity support
>>
>> Commit 0b0f9dc5 ("Revert "virtio_pci: use shared interrupts for
>> virtqueues"") removed the adjustment of the pre_vectors for the virtio
>> MSI-X vector allocation which was added in commit fb5e31d9 ("virtio:
>> allow drivers to request IRQ affinity when creating VQs"). This will
>> lead to an incorrect assignment of MSI-X vectors, and potential
>> deadlocks when offlining cpus.
>>
>> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
>> Fixes: 0b0f9dc5 ("Revert "virtio_pci: use shared interrupts for virtqueues")
>> Reported-by: YASUAKI ISHIMATSU <yasu.isimatu@xxxxxxxxx>
>
> Just gave it a go on an arm64 VM, and the behaviour seems much saner
> (the virtio queue affinity now spans the whole system).
>
> Tested-by: Marc Zyngier <marc.zyngier@xxxxxxx>
>
> Thanks,
>
> M.
>