RHEL7: CPU soft lockup reports in __ext4_es_shrink during shrink slab due to list_sort
Issue
- CPU soft lockup reports in __ext4_es_shrink during shrink slab and inside list_sort
[14632.767362] list passed to list_sort() too long for efficiency
[14646.303029] NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [kswapd0:516]
crash> bt
PID: 505 TASK: ffff88fe7aee4f10 CPU: 36 COMMAND: "kswapd0"
#0 [ffff887e7ce83cf8] machine_kexec at ffffffff8105d77b
#1 [ffff887e7ce83d58] __crash_kexec at ffffffff81108732
#2 [ffff887e7ce83e28] panic at ffffffff816a863f
#3 [ffff887e7ce83ea8] watchdog_timer_fn at ffffffff811334e1
#4 [ffff887e7ce83ee0] __hrtimer_run_queues at ffffffff810b8196
#5 [ffff887e7ce83f38] hrtimer_interrupt at ffffffff810b872f
#6 [ffff887e7ce83f80] local_apic_timer_interrupt at ffffffff8105467b
#7 [ffff887e7ce83f98] smp_apic_timer_interrupt at ffffffff816c4e73
#8 [ffff887e7ce83fb0] apic_timer_interrupt at ffffffff816c1732
--- <IRQ stack> ---
#9 [ffff887e7a4dba38] apic_timer_interrupt at ffffffff816c1732
[exception RIP: ext4_inode_touch_time_cmp+13]
RIP: ffffffffc024d57d RSP: ffff887e7a4dbae8 RFLAGS: 00000282
RAX: 0000088000080000 RBX: ffffffffffffff10 RCX: 00000003b0afb9af
RDX: ffff884f35a89790 RSI: ffff887e48307040 RDI: 0000000000000000
RBP: ffff887e7a4dbbe0 R8: ffff887e7a4dbba0 R9: 000000000156a2c0
R10: 0000000000000068 R11: 0000000000000000 R12: ffff8818df3ee020
R13: ffff884305a19790 R14: 00000003bcc12dec R15: 00000003bcc0fa2c
ORIG_RAX: ffffffffffffff10 CS: 0010 SS: 0018
#10 [ffff887e7a4dbaf0] list_sort at ffffffff8133c526
#11 [ffff887e7a4dbbe8] __ext4_es_shrink at ffffffffc024da6e [ext4]
#12 [ffff887e7a4dbc60] ext4_es_shrink at ffffffffc024dbf4 [ext4]
#13 [ffff887e7a4dbca8] shrink_slab at ffffffff811999a5
#14 [ffff887e7a4dbd48] balance_pgdat at ffffffff8119d661
#15 [ffff887e7a4dbe20] kswapd at ffffffff8119d903
#16 [ffff887e7a4dbec8] kthread at ffffffff810b4031
#17 [ffff887e7a4dbf50] ret_from_fork at ffffffff816c055d
Environment
- Red Hat Enterprise Linux 7
- Seen on Kernel-3.10.0-693.21.1.el7 / kernel-3.10.0-1127.el7
- ext4 filesystem
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