The kernel crashes due to a hard LOCKUP where a task is writing out a large sysrq-t data into a serial console.

Issue

• The kernel crashes due to a hard LOCKUP where a task is writing out a large sysrq-t data into a serial console.

[14784833.445402] Kernel panic - not syncing: Hard LOCKUP
[14784833.445404] CPU: 1 PID: 617 Comm: multipathd Tainted: G           OE  ------------   3.10.0-693.21.1.el7.x86_64 #1
[14784833.445404] Hardware name:    /02C2CP, BIOS 2.7.1 001/22/2018
[14784833.445405] Call Trace:
[14784833.445407]  <NMI>  [<ffffffff816ae7c8>] dump_stack+0x19/0x1b
[14784833.445409]  [<ffffffff816a8634>] panic+0xe8/0x21f
[14784833.445412]  [<ffffffff8102e7ed>] ? show_trace_log_lvl+0x4d/0x60
[14784833.445414]  [<ffffffff8108abaf>] nmi_panic+0x3f/0x40
[14784833.445416]  [<ffffffff81133905>] watchdog_overflow_callback+0xf5/0x100
[14784833.445417]  [<ffffffff81172857>] __perf_event_overflow+0x57/0x100
[14784833.445420]  [<ffffffff8117b4a4>] perf_event_overflow+0x14/0x20
[14784833.445422]  [<ffffffff8100a078>] intel_pmu_handle_irq+0x218/0x500
[14784833.445423]  [<ffffffff8132ac6c>] ? ioremap_page_range+0x26c/0x3d0
[14784833.445425]  [<ffffffff811c5284>] ? vunmap_page_range+0x1b4/0x300
[14784833.445427]  [<ffffffff813e1146>] ? ghes_copy_tofrom_phys+0x116/0x210
[14784833.445428]  [<ffffffff813e12e0>] ? ghes_read_estatus+0xa0/0x190
[14784833.445431]  [<ffffffff816b7031>] perf_event_nmi_handler+0x31/0x50
[14784833.445432]  [<ffffffff816b892c>] nmi_handle.isra.0+0x8c/0x160
[14784833.445434]  [<ffffffff816b8b5d>] do_nmi+0x15d/0x460
[14784833.445436]  [<ffffffff816b7d89>] end_repeat_nmi+0x1e/0x7e
[14784833.445439]  [<ffffffff810fe1f2>] ? queued_write_lock_slowpath+0x62/0x90
[14784833.445441]  [<ffffffff810fe1f2>] ? queued_write_lock_slowpath+0x62/0x90
[14784833.445442]  [<ffffffff810fe1f2>] ? queued_write_lock_slowpath+0x62/0x90
[14784833.445445]  <<EOE>>  [<ffffffff816b6a51>] _raw_qwrite_lock+0x21/0x30
[14784833.445447]  [<ffffffff8108750b>] tasklist_write_lock_irq+0x3b/0x50
[14784833.445448]  [<ffffffff81089833>] copy_process+0x1473/0x1970
[14784833.445450]  [<ffffffff81089ee1>] do_fork+0x91/0x320
[14784833.445452]  [<ffffffff8108a1f6>] SyS_clone+0x16/0x20
[14784833.445454]  [<ffffffff816c0ad4>] stub_clone+0x44/0x70
[14784833.445456]  [<ffffffff816c0715>] ? system_call_fastpath+0x1c/0x21