Re: [PATCH V2 00/20] blk-mq-sched: improve SCSI-MQ performance

[Laurence Oberman <loberman@redhat.com>]

On 08/07/2017 11:27 AM, Bart Van Assche wrote:
> On Mon, 2017-08-07 at 08:48 -0400, Laurence Oberman wrote:
>> I tested this series using Ming's tests as well as my own set of tests
>> typically run against changes to upstream code in my SRP test-bed.
>> My tests also include very large sequential buffered and un-buffered I/O.
>>
>> This series seems to be fine for me. I did uncover another issue that is
>> unrelated to these patches and also exists in 4.13-RC3 generic that I am
>> still debugging.
> 
> Hello Laurence,
> 
> What kind of tests did you run? Only functional tests or also performance
> tests?
> 
> Has the issue you encountered with kernel 4.13-rc3 already been reported on
> the linux-rdma mailing list?
> 
> Thanks,
> 
> Bart.
> 

Hi Bart

Actually I was focusing on just performance to see if we had any 
regressions with Mings new patches for the large sequential I/O cases.

Ming had already tested the small I/O performance cases so I was making 
sure the large I/O sequential tests did not suffer.

The 4MB un-buffered direct read tests to DM devices seems to perform 
much the same in my test bed.
The 4MB buffered and un-buffered 4MB writes also seem to be well behaved 
with not much improvement.

These were not exhaustive tests and did not include my usual port 
disconnect and recovery tests either.
I was just making sure we did not regress with Ming's changes.

I was only just starting to baseline test the mq-deadline scheduler as 
prior to 4.13-RC3 I had not been testing any of the new MQ schedulers.
I had always only tested with [none]

The tests were with [none] and [mq-deadline]

The new issue I started seeing was not yet reported yet as I was still 
investigating it.

In summary:
With buffered writes we see the clone fail in blk_get_request in both 
Mings kernel and in the upstream 4.13-RC3 stock kernel

[  885.271451] io scheduler mq-deadline registered
[  898.455442] device-mapper: multipath: blk_get_request() returned -11 
- requeuing

This is due to

multipath_clone_and_map()

/*
  * Map cloned requests (request-based multipath)
  */
static int multipath_clone_and_map(struct dm_target *ti, struct request *rq,
                                    union map_info *map_context,
                                    struct request **__clone)
{
..
..
..
         clone = blk_get_request(q, rq->cmd_flags | REQ_NOMERGE, 
GFP_ATOMIC);
         if (IS_ERR(clone)) {
                 /* EBUSY, ENODEV or EWOULDBLOCK: requeue */
                 bool queue_dying = blk_queue_dying(q);
                 DMERR_LIMIT("blk_get_request() returned %ld%s - requeuing",
                             PTR_ERR(clone), queue_dying ? " (path 
offline)" : "");
                 if (queue_dying) {
                         atomic_inc(&m->pg_init_in_progress);
                         activate_or_offline_path(pgpath);
                         return DM_MAPIO_REQUEUE;
                 }
                 return DM_MAPIO_DELAY_REQUEUE;
         }

Still investigating but it leads to a hard lockup


So I still need to see if the hard-lockup happens in the stock kernel 
with mq-deadline and some other work before coming up with a full 
summary of the issue.

I also intend to re-run all tests including disconnect and reconnect 
tests on both mq-deadline and none.

Trace below


[ 1553.167357] NMI watchdog: Watchdog detected hard LOCKUP on cpu 4
[ 1553.167359] Modules linked in: mq_deadline binfmt_misc dm_round_robin 
xt_CHECKSUM ipt_MASQUERADE nf_nat_masquerade_ipv4 tun ip6t_rpfilter 
ipt_REJECT nf_reject_ipv4 ip6t_REJECT nf_reject_ipv6 xt_conntrack ip_set 
nfnetlink ebtable_nat ebtable_broute bridge stp llc ip6table_nat 
nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 rpcrdma ip6table_mangle 
ip6table_security ip6table_raw iptable_nat ib_isert nf_conntrack_ipv4 
iscsi_target_mod nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack ib_iser 
libiscsi scsi_transport_iscsi iptable_mangle iptable_security 
iptable_raw ebtable_filter ebtables target_core_mod ip6table_filter 
ip6_tables iptable_filter ib_srp scsi_transport_srp ib_ipoib rdma_ucm 
ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm mlx5_ib ib_core 
intel_powerclamp coretemp kvm_intel kvm irqbypass crct10dif_pclmul
[ 1553.167385]  crc32_pclmul ghash_clmulni_intel pcbc aesni_intel sg 
joydev ipmi_si hpilo crypto_simd hpwdt iTCO_wdt cryptd ipmi_devintf 
glue_helper gpio_ich iTCO_vendor_support shpchp ipmi_msghandler pcspkr 
acpi_power_meter i7core_edac lpc_ich pcc_cpufreq nfsd auth_rpcgss 
nfs_acl lockd grace sunrpc dm_multipath ip_tables xfs libcrc32c sd_mod 
amdkfd amd_iommu_v2 radeon i2c_algo_bit drm_kms_helper syscopyarea 
sysfillrect sysimgblt fb_sys_fops ttm mlx5_core drm mlxfw i2c_core ptp 
serio_raw hpsa crc32c_intel bnx2 pps_core devlink scsi_transport_sas 
dm_mirror dm_region_hash dm_log dm_mod [last unloaded: ib_srpt]
[ 1553.167410] CPU: 4 PID: 11532 Comm: dd Tainted: G          I 
4.13.0-rc3lobeming.ming_V4+ #20
[ 1553.167411] Hardware name: HP ProLiant DL380 G7, BIOS P67 08/16/2015
[ 1553.167412] task: ffff9d9344b0d800 task.stack: ffffb5cb913b0000
[ 1553.167421] RIP: 0010:__blk_recalc_rq_segments+0xec/0x3d0
[ 1553.167421] RSP: 0018:ffff9d9377a83d08 EFLAGS: 00000046
[ 1553.167422] RAX: 0000000000001000 RBX: 0000000000001000 RCX: 
ffff9d91b8e9f500
[ 1553.167423] RDX: fffffcd56af20f00 RSI: ffff9d91b8e9f588 RDI: 
ffff9d91b8e9f488
[ 1553.167424] RBP: ffff9d9377a83d88 R08: 000000000003c000 R09: 
0000000000000001
[ 1553.167424] R10: 0000000000000000 R11: 0000000000000000 R12: 
0000000000000000
[ 1553.167425] R13: 0000000000000000 R14: 0000000000000000 R15: 
0000000000000003
[ 1553.167426] FS:  00007f3061002740(0000) GS:ffff9d9377a80000(0000) 
knlGS:0000000000000000
[ 1553.167427] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1553.167428] CR2: 00007f305a511000 CR3: 0000000b1bfb2000 CR4: 
00000000000006e0
[ 1553.167429] Call Trace:
[ 1553.167432]  <IRQ>
[ 1553.167437]  ? mempool_free+0x2b/0x80
[ 1553.167440]  blk_recalc_rq_segments+0x28/0x40
[ 1553.167442]  blk_update_request+0x249/0x310
[ 1553.167450]  end_clone_bio+0x46/0x70 [dm_mod]
[ 1553.167453]  bio_endio+0xa1/0x120
[ 1553.167454]  blk_update_request+0xb7/0x310
[ 1553.167457]  scsi_end_request+0x38/0x1d0
[ 1553.167458]  scsi_io_completion+0x13c/0x630
[ 1553.167460]  scsi_finish_command+0xd9/0x120
[ 1553.167462]  scsi_softirq_done+0x12a/0x150
[ 1553.167463]  __blk_mq_complete_request_remote+0x13/0x20
[ 1553.167466]  flush_smp_call_function_queue+0x52/0x110
[ 1553.167468]  generic_smp_call_function_single_interrupt+0x13/0x30
[ 1553.167470]  smp_call_function_single_interrupt+0x27/0x40
[ 1553.167471]  call_function_single_interrupt+0x93/0xa0
[ 1553.167473] RIP: 0010:radix_tree_next_chunk+0xcb/0x2e0
[ 1553.167474] RSP: 0018:ffffb5cb913b3a68 EFLAGS: 00000203 ORIG_RAX: 
ffffffffffffff04
[ 1553.167475] RAX: 0000000000000001 RBX: 0000000000000010 RCX: 
ffff9d9e2c556938
[ 1553.167476] RDX: ffff9d93053c5919 RSI: 0000000000000001 RDI: 
ffff9d9e2c556910
[ 1553.167476] RBP: ffffb5cb913b3ab8 R08: ffffb5cb913b3bc0 R09: 
0000000ab7d52000
[ 1553.167477] R10: fffffcd56adf5440 R11: 0000000000000000 R12: 
0000000000000230
[ 1553.167477] R13: 0000000000000000 R14: 000000000006e0fe R15: 
ffff9d9e2c556910
[ 1553.167478]  </IRQ>
[ 1553.167480]  ? radix_tree_next_chunk+0x10b/0x2e0
[ 1553.167481]  find_get_pages_tag+0x149/0x270
[ 1553.167485]  ? block_write_full_page+0xcd/0xe0
[ 1553.167487]  pagevec_lookup_tag+0x21/0x30
[ 1553.167488]  write_cache_pages+0x14c/0x510
[ 1553.167490]  ? __wb_calc_thresh+0x140/0x140
[ 1553.167492]  generic_writepages+0x51/0x80
[ 1553.167493]  blkdev_writepages+0x2f/0x40
[ 1553.167494]  do_writepages+0x1c/0x70
[ 1553.167495]  __filemap_fdatawrite_range+0xc6/0x100
[ 1553.167497]  filemap_write_and_wait+0x3d/0x80
[ 1553.167498]  __sync_blockdev+0x1f/0x40
[ 1553.167499]  __blkdev_put+0x74/0x200
[ 1553.167500]  blkdev_put+0x4c/0xd0
[ 1553.167501]  blkdev_close+0x25/0x30
[ 1553.167503]  __fput+0xe7/0x210
[ 1553.167504]  ____fput+0xe/0x10
[ 1553.167508]  task_work_run+0x83/0xb0
[ 1553.167511]  exit_to_usermode_loop+0x66/0x98
[ 1553.167512]  do_syscall_64+0x13a/0x150
[ 1553.167519]  entry_SYSCALL64_slow_path+0x25/0x25
[ 1553.167520] RIP: 0033:0x7f3060b25bd0
[ 1553.167521] RSP: 002b:00007ffc5e6b12c8 EFLAGS: 00000246 ORIG_RAX: 
0000000000000003
[ 1553.167522] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 
00007f3060b25bd0
[ 1553.167522] RDX: 0000000000400000 RSI: 0000000000000000 RDI: 
0000000000000001
[ 1553.167523] RBP: 0000000000000320 R08: ffffffffffffffff R09: 
0000000000402003
[ 1553.167524] R10: 00007ffc5e6b1040 R11: 0000000000000246 R12: 
0000000000000320
[ 1553.167525] R13: 0000000000000000 R14: 00007ffc5e6b2618 R15: 
00007ffc5e6b1540
[ 1553.167526] Code: db 0f 84 92 01 00 00 45 89 f5 45 89 e2 4c 89 ee 48 
c1 e6 04 48 03 71 78 8b 46 08 48 8b 16 44 29 e0 48 89 54 24 30 39 d8 0f 
47 c3 <44> 03 56 0c 45 84 db 89 44 24 38 44 89 54 24 3c 0f 85 2a 01 00
[ 1553.167540] Kernel panic - not syncing: Hard LOCKUP
[ 1553.167542] CPU: 4 PID: 11532 Comm: dd Tainted: G          I 
4.13.0-rc3lobeming.ming_V4+ #20
[ 1553.167542] Hardware name: HP ProLiant DL380 G7, BIOS P67 08/16/2015
[ 1553.167543] Call Trace:
[ 1553.167543]  <NMI>
[ 1553.167545]  dump_stack+0x63/0x87
[ 1553.167548]  panic+0xeb/0x245
[ 1553.167550]  nmi_panic+0x3f/0x40
[ 1553.167553]  watchdog_overflow_callback+0xce/0xf0
[ 1553.167556]  __perf_event_overflow+0x54/0xe0
[ 1553.167559]  perf_event_overflow+0x14/0x20
[ 1553.167562]  intel_pmu_handle_irq+0x203/0x4b0
[ 1553.167566]  perf_event_nmi_handler+0x2d/0x50
[ 1553.167568]  nmi_handle+0x61/0x110
[ 1553.167569]  default_do_nmi+0x44/0x120
[ 1553.167571]  do_nmi+0x113/0x190
[ 1553.167573]  end_repeat_nmi+0x1a/0x1e
[ 1553.167574] RIP: 0010:__blk_recalc_rq_segments+0xec/0x3d0
[ 1553.167575] RSP: 0018:ffff9d9377a83d08 EFLAGS: 00000046
[ 1553.167576] RAX: 0000000000001000 RBX: 0000000000001000 RCX: 
ffff9d91b8e9f500
[ 1553.167576] RDX: fffffcd56af20f00 RSI: ffff9d91b8e9f588 RDI: 
ffff9d91b8e9f488
[ 1553.167577] RBP: ffff9d9377a83d88 R08: 000000000003c000 R09: 
0000000000000001
[ 1553.167577] R10: 0000000000000000 R11: 0000000000000000 R12: 
0000000000000000
[ 1553.167578] R13: 0000000000000000 R14: 0000000000000000 R15: 
0000000000000003
[ 1553.167580]  ? __blk_recalc_rq_segments+0xec/0x3d0
[ 1553.167581]  ? __blk_recalc_rq_segments+0xec/0x3d0
[ 1553.167582]  </NMI>
[ 1553.167582]  <IRQ>
[ 1553.167584]  ? mempool_free+0x2b/0x80
[ 1553.167585]  blk_recalc_rq_segments+0x28/0x40
[ 1553.167586]  blk_update_request+0x249/0x310
[ 1553.167590]  end_clone_bio+0x46/0x70 [dm_mod]
[ 1553.167592]  bio_endio+0xa1/0x120
[ 1553.167593]  blk_update_request+0xb7/0x310
[ 1553.167594]  scsi_end_request+0x38/0x1d0
[ 1553.167595]  scsi_io_completion+0x13c/0x630
[ 1553.167597]  scsi_finish_command+0xd9/0x120
[ 1553.167598]  scsi_softirq_done+0x12a/0x150
[ 1553.167599]  __blk_mq_complete_request_remote+0x13/0x20
[ 1553.167601]  flush_smp_call_function_queue+0x52/0x110
[ 1553.167602]  generic_smp_call_function_single_interrupt+0x13/0x30
[ 1553.167603]  smp_call_function_single_interrupt+0x27/0x40
[ 1553.167604]  call_function_single_interrupt+0x93/0xa0
[ 1553.167605] RIP: 0010:radix_tree_next_chunk+0xcb/0x2e0
[ 1553.167606] RSP: 0018:ffffb5cb913b3a68 EFLAGS: 00000203 ORIG_RAX: 
ffffffffffffff04
[ 1553.167607] RAX: 0000000000000001 RBX: 0000000000000010 RCX: 
ffff9d9e2c556938
[ 1553.167607] RDX: ffff9d93053c5919 RSI: 0000000000000001 RDI: 
ffff9d9e2c556910
[ 1553.167608] RBP: ffffb5cb913b3ab8 R08: ffffb5cb913b3bc0 R09: 
0000000ab7d52000
[ 1553.167609] R10: fffffcd56adf5440 R11: 0000000000000000 R12: 
0000000000000230
[ 1553.167609] R13: 0000000000000000 R14: 000000000006e0fe R15: 
ffff9d9e2c556910
[ 1553.167610]  </IRQ>
[ 1553.167611]  ? radix_tree_next_chunk+0x10b/0x2e0
[ 1553.167613]  find_get_pages_tag+0x149/0x270
[ 1553.167615]  ? block_write_full_page+0xcd/0xe0
[ 1553.167616]  pagevec_lookup_tag+0x21/0x30
[ 1553.167617]  write_cache_pages+0x14c/0x510
[ 1553.167619]  ? __wb_calc_thresh+0x140/0x140
[ 1553.167621]  generic_writepages+0x51/0x80
[ 1553.167622]  blkdev_writepages+0x2f/0x40
[ 1553.167623]  do_writepages+0x1c/0x70
[ 1553.167627]  __filemap_fdatawrite_range+0xc6/0x100
[ 1553.167629]  filemap_write_and_wait+0x3d/0x80
[ 1553.167630]  __sync_blockdev+0x1f/0x40
[ 1553.167631]  __blkdev_put+0x74/0x200
[ 1553.167632]  blkdev_put+0x4c/0xd0
[ 1553.167633]  blkdev_close+0x25/0x30
[ 1553.167634]  __fput+0xe7/0x210
[ 1553.167635]  ____fput+0xe/0x10
[ 1553.167636]  task_work_run+0x83/0xb0
[ 1553.167637]  exit_to_usermode_loop+0x66/0x98
[ 1553.167638]  do_syscall_64+0x13a/0x150
[ 1553.167640]  entry_SYSCALL64_slow_path+0x25/0x25
[ 1553.167641] RIP: 0033:0x7f3060b25bd0
[ 1553.167641] RSP: 002b:00007ffc5e6b12c8 EFLAGS: 00000246 ORIG_RAX: 
0000000000000003
[ 1553.167642] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 
00007f3060b25bd0
[ 1553.167643] RDX: 0000000000400000 RSI: 0000000000000000 RDI: 
0000000000000001
[ 1553.167643] RBP: 0000000000000320 R08: ffffffffffffffff R09: 
0000000000402003
[ 1553.167644] R10: 00007ffc5e6b1040 R11: 0000000000000246 R12: 
0000000000000320
[ 1553.167645] R13: 0000000000000000 R14: 00007ffc5e6b2618 R15: 
00007ffc5e6b1540
[ 1553.167829] Kernel Offset: 0x2f400000 from 0xffffffff81000000 
(relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[ 1558.119352] ---[ end Kernel panic - not syncing: Hard LOCKUP
[ 1558.151334] sched: Unexpected reschedule of offline CPU#0!
[ 1558.151342] ------------[ cut here ]------------
[ 1558.151347] WARNING: CPU: 4 PID: 11532 at arch/x86/kernel/smp.c:128 
native_smp_send_reschedule+0x3c/0x40
[ 1558.151348] Modules linked in: mq_deadline binfmt_misc dm_round_robin 
xt_CHECKSUM ipt_MASQUERADE nf_nat_masquerade_ipv4 tun ip6t_rpfilter 
ipt_REJECT nf_reject_ipv4 ip6t_REJECT nf_reject_ipv6 xt_conntrack ip_set 
nfnetlink ebtable_nat ebtable_broute bridge stp llc ip6table_nat 
nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 rpcrdma ip6table_mangle 
ip6table_security ip6table_raw iptable_nat ib_isert nf_conntrack_ipv4 
iscsi_target_mod nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack ib_iser 
libiscsi scsi_transport_iscsi iptable_mangle iptable_security 
iptable_raw ebtable_filter ebtables target_core_mod ip6table_filter 
ip6_tables iptable_filter ib_srp scsi_transport_srp ib_ipoib rdma_ucm 
ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm mlx5_ib ib_core 
intel_powerclamp coretemp kvm_intel kvm irqbypass crct10dif_pclmul
[ 1558.151363]  crc32_pclmul ghash_clmulni_intel pcbc aesni_intel sg 
joydev ipmi_si hpilo crypto_simd hpwdt iTCO_wdt cryptd ipmi_devintf 
glue_helper gpio_ich iTCO_vendor_support shpchp ipmi_msghandler pcspkr 
acpi_power_meter i7core_edac lpc_ich pcc_cpufreq nfsd auth_rpcgss 
nfs_acl lockd grace sunrpc dm_multipath ip_tables xfs libcrc32c sd_mod 
amdkfd amd_iommu_v2 radeon i2c_algo_bit drm_kms_helper syscopyarea 
sysfillrect sysimgblt fb_sys_fops ttm mlx5_core drm mlxfw i2c_core ptp 
serio_raw hpsa crc32c_intel bnx2 pps_core devlink scsi_transport_sas 
dm_mirror dm_region_hash dm_log dm_mod [last unloaded: ib_srpt]
[ 1558.151377] CPU: 4 PID: 11532 Comm: dd Tainted: G          I 
4.13.0-rc3lobeming.ming_V4+ #20
[ 1558.151378] Hardware name: HP ProLiant DL380 G7, BIOS P67 08/16/2015
[ 1558.151379] task: ffff9d9344b0d800 task.stack: ffffb5cb913b0000
[ 1558.151380] RIP: 0010:native_smp_send_reschedule+0x3c/0x40
[ 1558.151381] RSP: 0018:ffff9d9377a856a0 EFLAGS: 00010046
[ 1558.151382] RAX: 000000000000002e RBX: 0000000000000000 RCX: 
0000000000000006
[ 1558.151383] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 
ffff9d9377a8e010
[ 1558.151383] RBP: ffff9d9377a856a0 R08: 000000000000002e R09: 
ffff9d9fa7029552
[ 1558.151384] R10: 0000000000000732 R11: 0000000000000000 R12: 
ffff9d9377a1bb00
[ 1558.151384] R13: ffff9d936ef70000 R14: ffff9d9377a85758 R15: 
ffff9d9377a1bb00
[ 1558.151385] FS:  00007f3061002740(0000) GS:ffff9d9377a80000(0000) 
knlGS:0000000000000000
[ 1558.151386] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1558.151387] CR2: 00007f305a511000 CR3: 0000000b1bfb2000 CR4: 
00000000000006e0
[ 1558.151387] Call Trace:
[ 1558.151388]  <NMI>
[ 1558.151391]  resched_curr+0xa1/0xc0
[ 1558.151392]  check_preempt_curr+0x79/0x90
[ 1558.151393]  ttwu_do_wakeup+0x1e/0x160
[ 1558.151395]  ttwu_do_activate+0x7a/0x90
[ 1558.151396]  try_to_wake_up+0x1e1/0x470
[ 1558.151398]  ? vsnprintf+0x1fa/0x4a0
[ 1558.151399]  default_wake_function+0x12/0x20
[ 1558.151403]  __wake_up_common+0x55/0x90
[ 1558.151405]  __wake_up_locked+0x13/0x20
[ 1558.151408]  ep_poll_callback+0xd3/0x2a0
[ 1558.151409]  __wake_up_common+0x55/0x90
[ 1558.151411]  __wake_up+0x39/0x50
[ 1558.151415]  wake_up_klogd_work_func+0x40/0x60
[ 1558.151419]  irq_work_run_list+0x4d/0x70
[ 1558.151421]  ? tick_sched_do_timer+0x70/0x70
[ 1558.151422]  irq_work_tick+0x40/0x50
[ 1558.151424]  update_process_times+0x42/0x60
[ 1558.151426]  tick_sched_handle+0x2d/0x60
[ 1558.151427]  tick_sched_timer+0x39/0x70
[ 1558.151428]  __hrtimer_run_queues+0xe5/0x230
[ 1558.151429]  hrtimer_interrupt+0xa8/0x1a0
[ 1558.151431]  local_apic_timer_interrupt+0x35/0x60
[ 1558.151432]  smp_apic_timer_interrupt+0x38/0x50
[ 1558.151433]  apic_timer_interrupt+0x93/0xa0
[ 1558.151435] RIP: 0010:panic+0x1fa/0x245
[ 1558.151435] RSP: 0018:ffff9d9377a85b30 EFLAGS: 00000246 ORIG_RAX: 
ffffffffffffff10
[ 1558.151436] RAX: 0000000000000030 RBX: ffff9d890c5d0000 RCX: 
0000000000000006
[ 1558.151437] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 
ffff9d9377a8e010
[ 1558.151438] RBP: ffff9d9377a85ba0 R08: 0000000000000030 R09: 
ffff9d9fa7029514
[ 1558.151438] R10: 0000000000000731 R11: 0000000000000000 R12: 
ffffffffb0e63f7f
[ 1558.151439] R13: 0000000000000000 R14: 0000000000000000 R15: 
0000000000000000
[ 1558.151441]  nmi_panic+0x3f/0x40
[ 1558.151442]  watchdog_overflow_callback+0xce/0xf0
[ 1558.151444]  __perf_event_overflow+0x54/0xe0
[ 1558.151445]  perf_event_overflow+0x14/0x20
[ 1558.151446]  intel_pmu_handle_irq+0x203/0x4b0
[ 1558.151449]  perf_event_nmi_handler+0x2d/0x50
[ 1558.151450]  nmi_handle+0x61/0x110
[ 1558.151452]  default_do_nmi+0x44/0x120
[ 1558.151453]  do_nmi+0x113/0x190
[ 1558.151454]  end_repeat_nmi+0x1a/0x1e
[ 1558.151456] RIP: 0010:__blk_recalc_rq_segments+0xec/0x3d0
[ 1558.151456] RSP: 0018:ffff9d9377a83d08 EFLAGS: 00000046
[ 1558.151457] RAX: 0000000000001000 RBX: 0000000000001000 RCX: 
ffff9d91b8e9f500
[ 1558.151458] RDX: fffffcd56af20f00 RSI: ffff9d91b8e9f588 RDI: 
ffff9d91b8e9f488
[ 1558.151458] RBP: ffff9d9377a83d88 R08: 000000000003c000 R09: 
0000000000000001
[ 1558.151459] R10: 0000000000000000 R11: 0000000000000000 R12: 
0000000000000000
[ 1558.151459] R13: 0000000000000000 R14: 0000000000000000 R15: 
0000000000000003
[ 1558.151461]  ? __blk_recalc_rq_segments+0xec/0x3d0
[ 1558.151463]  ? __blk_recalc_rq_segments+0xec/0x3d0
[ 1558.151463]  </NMI>
[ 1558.151464]  <IRQ>
[ 1558.151465]  ? mempool_free+0x2b/0x80
[ 1558.151467]  blk_recalc_rq_segments+0x28/0x40
[ 1558.151468]  blk_update_request+0x249/0x310
[ 1558.151472]  end_clone_bio+0x46/0x70 [dm_mod]
[ 1558.151473]  bio_endio+0xa1/0x120
[ 1558.151474]  blk_update_request+0xb7/0x310
[ 1558.151476]  scsi_end_request+0x38/0x1d0
[ 1558.151477]  scsi_io_completion+0x13c/0x630
[ 1558.151478]  scsi_finish_command+0xd9/0x120
[ 1558.151480]  scsi_softirq_done+0x12a/0x150
[ 1558.151481]  __blk_mq_complete_request_remote+0x13/0x20
[ 1558.151483]  flush_smp_call_function_queue+0x52/0x110
[ 1558.151484]  generic_smp_call_function_single_interrupt+0x13/0x30
[ 1558.151485]  smp_call_function_single_interrupt+0x27/0x40
[ 1558.151486]  call_function_single_interrupt+0x93/0xa0
[ 1558.151487] RIP: 0010:radix_tree_next_chunk+0xcb/0x2e0
[ 1558.151488] RSP: 0018:ffffb5cb913b3a68 EFLAGS: 00000203 ORIG_RAX: 
ffffffffffffff04
[ 1558.151489] RAX: 0000000000000001 RBX: 0000000000000010 RCX: 
ffff9d9e2c556938
[ 1558.151490] RDX: ffff9d93053c5919 RSI: 0000000000000001 RDI: 
ffff9d9e2c556910
[ 1558.151490] RBP: ffffb5cb913b3ab8 R08: ffffb5cb913b3bc0 R09: 
0000000ab7d52000
[ 1558.151491] R10: fffffcd56adf5440 R11: 0000000000000000 R12: 
0000000000000230
[ 1558.151492] R13: 0000000000000000 R14: 000000000006e0fe R15: 
ffff9d9e2c556910
[ 1558.151492]  </IRQ>
[ 1558.151494]  ? radix_tree_next_chunk+0x10b/0x2e0
[ 1558.151496]  find_get_pages_tag+0x149/0x270
[ 1558.151497]  ? block_write_full_page+0xcd/0xe0
[ 1558.151499]  pagevec_lookup_tag+0x21/0x30
[ 1558.151500]  write_cache_pages+0x14c/0x510
[ 1558.151502]  ? __wb_calc_thresh+0x140/0x140
[ 1558.151504]  generic_writepages+0x51/0x80
[ 1558.151505]  blkdev_writepages+0x2f/0x40
[ 1558.151506]  do_writepages+0x1c/0x70
[ 1558.151507]  __filemap_fdatawrite_range+0xc6/0x100
[ 1558.151509]  filemap_write_and_wait+0x3d/0x80
[ 1558.151510]  __sync_blockdev+0x1f/0x40
[ 1558.151511]  __blkdev_put+0x74/0x200
[ 1558.151512]  blkdev_put+0x4c/0xd0
[ 1558.151513]  blkdev_close+0x25/0x30
[ 1558.151514]  __fput+0xe7/0x210
[ 1558.151515]  ____fput+0xe/0x10
[ 1558.151517]  task_work_run+0x83/0xb0
[ 1558.151518]  exit_to_usermode_loop+0x66/0x98
[ 1558.151519]  do_syscall_64+0x13a/0x150
[ 1558.151521]  entry_SYSCALL64_slow_path+0x25/0x25
[ 1558.151522] RIP: 0033:0x7f3060b25bd0
[ 1558.151522] RSP: 002b:00007ffc5e6b12c8 EFLAGS: 00000246 ORIG_RAX: 
0000000000000003
[ 1558.151523] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 
00007f3060b25bd0
[ 1558.151524] RDX: 0000000000400000 RSI: 0000000000000000 RDI: 
0000000000000001
[ 1558.151524] RBP: 0000000000000320 R08: ffffffffffffffff R09: 
0000000000402003
[ 1558.151525] R10: 00007ffc5e6b1040 R11: 0000000000000246 R12: 
0000000000000320
[ 1558.151526] R13: 0000000000000000 R14: 00007ffc5e6b2618 R15: 
00007ffc5e6b1540
[ 1558.151527] Code: dc 00 0f 92 c0 84 c0 74 14 48 8b 05 ff 9d a9 00 be 
fd 00 00 00 ff 90 a0 00 00 00 5d c3 89 fe 48 c7 c7 90 4d e3 b0 e8 c7 db 
09 00 <0f> ff 5d c3 66 66 66 66 90 55 48 89 e5 48 83 ec 20 65 48 8b 04
[ 1558.151540] ---[ end trace 408c28f8c132530c ]---