Leo Yan
2017-07-24 14:34:17 UTC
Hi all,
We found the mainline arm64 kernel boot failure on Hikey960 board,
this is caused by patch f2545b2d4ce1 (jump_label: Reorder hotplug lock
and jump_label_lock), this patch adds locking cpus_read_lock() in
function static_key_slow_inc() and introduce the dead lock issue by
acquiring lock twice. Below are detailed flow:
arch_timer_register()
`> cpuhp_setup_state()
`> __cpuhp_setup_state()
cpus_read_lock()
`> __cpuhp_setup_state_cpuslocked()
`> cpuhp_issue_call()
`> arch_timer_starting_cpu()
`> __arch_timer_setup()
`> arch_timer_check_ool_workaround()
`> arch_timer_enable_workaround()
`> static_branch_enable()
`> static_key_enable()
`> static_key_slow_inc()
`> cpus_read_lock()
So finally there have called cpus_read_lock() twice, and kernel report
log as below. So I am not sure what's the best way to fix this issue,
could you give some suggestion for this? Thanks.
---8<---
** 510118 printk messages dropped ** [ 1.299405] [<ffff000008831140>] arch_timer_check_ool_workaround+0xc8/0x1fc
** 5516 printk messages dropped ** [ 1.309965] [<ffff00000899d3a4>] schedule+0x38/0x9c
** 4289 printk messages dropped ** [ 1.317961] [<ffff00000899d3a4>] schedule+0x38/0x9c
** 4293 printk messages dropped ** [ 1.325961] [<ffff000008172370>] static_key_slow_inc+0xc8/0x124
** 4857 printk messages dropped ** [ 1.335010] [<ffff00000899d3a4>] schedule+0x38/0x9c
** 4290 printk messages dropped ** [ 1.343008] [<ffff0000089a0260>] rwsem_down_read_failed+0xdc/0x108
** 4999 printk messages dropped ** [ 1.352325] [<ffff000008831584>] arch_timer_starting_cpu+0xf8/0x2c4
** 5048 printk messages dropped ** [ 1.361726] [<ffff000008989e70>] dump_stack+0x90/0xb0
** 4381 printk messages dropped ** [ 1.369892] [<ffff00000899d3a4>] schedule+0x38/0x9c
** 4291 printk messages dropped ** [ 1.377895] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4811 printk messages dropped ** [ 1.386856] [<ffff000008989e70>] dump_stack+0x90/0xb0
** 4384 printk messages dropped ** [ 1.395026] [<ffff0000080c1e44>] cpus_read_lock+0x70/0x74
** 4575 printk messages dropped ** [ 1.403553] [<ffff0000080c1e44>] cpus_read_lock+0x70/0x74
** 4572 printk messages dropped ** [ 1.412071] [<ffff00000899d3a4>] schedule+0x38/0x9c
** 4291 printk messages dropped ** [ 1.420070] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4812 printk messages dropped ** [ 1.429034] [<ffff0000080eacb4>] dequeue_task_idle+0x24/0x38
** 4714 printk messages dropped ** [ 1.437821] [<ffff000008172370>] static_key_slow_inc+0xc8/0x124
** 4855 printk messages dropped ** [ 1.446871] [<ffff0000080e53f8>] deactivate_task+0x70/0xac
** 4620 printk messages dropped ** [ 1.455480] [<ffff00000899cfec>] __schedule+0x244/0x5c4
** 4480 printk messages dropped ** [ 1.463828] Hardware name: HiKey960 (DT)
** 3771 printk messages dropped ** [ 1.470855] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4808 printk messages dropped ** [ 1.479815] Call trace:
** 2965 printk messages dropped ** [ 1.485352] [<00000000009a81b4>] 0x9a81b4
** 3818 printk messages dropped ** [ 1.492473] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4808 printk messages dropped ** [ 1.501436] Call trace:
** 2968 printk messages dropped ** [ 1.506971] Hardware name: HiKey960 (DT)
** 3769 printk messages dropped ** [ 1.514005] [<ffff00000899d3a4>] schedule+0x38/0x9c
** 4288 printk messages dropped ** [ 1.522001] [<ffff00000899cfec>] __schedule+0x244/0x5c4
** 4473 printk messages dropped ** [ 1.530347] [<ffff000008831584>] arch_timer_starting_cpu+0xf8/0x2c4
** 5041 printk messages dropped ** [ 1.539747] [<00000000009a81b4>] 0x9a81b4
** 3819 printk messages dropped ** [ 1.546867] [<ffff0000080c1e44>] cpus_read_lock+0x70/0x74
** 4572 printk messages dropped ** [ 1.555393] [<ffff00000899d3a4>] schedule+0x38/0x9c
** 4288 printk messages dropped ** [ 1.563390] [<ffff00000899cfec>] __schedule+0x244/0x5c4
** 4473 printk messages dropped ** [ 1.571734] [<ffff000008831584>] arch_timer_starting_cpu+0xf8/0x2c4
** 5043 printk messages dropped ** [ 1.581138] CPU: 4 PID: 0 Comm: swapper/4 Tainted: G S W 4.13.0-rc1-linaro-hikey960+ #30
** 6551 printk messages dropped ** [ 1.593352] [<ffff0000080c3640>] notify_cpu_starting+0x68/0x88
** 4807 printk messages dropped ** [ 1.602312] [<ffff00000899cfec>] __schedule+0x244/0x5c4
** 4476 printk messages dropped ** [ 1.610663] [<ffff00000808e9d0>] secondary_start_kernel+0xb0/0x118
** 4996 printk messages dropped ** [ 1.619972] CPU: 4 PID: 0 Comm: swapper/4 Tainted: G S W 4.13.0-rc1-linaro-hikey960+ #30
** 6553 printk messages dropped ** [ 1.632182] [<00000000009a81b4>] 0x9a81b4
** 3820 printk messages dropped ** [ 1.639301] [<ffff000008172370>] static_key_slow_inc+0xc8/0x124
** 4854 printk messages dropped ** [ 1.648349] [<ffff0000080eacb4>] dequeue_task_idle+0x24/0x38
** 4712 printk messages dropped ** [ 1.657139] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4804 printk messages dropped ** [ 1.666098] [<00000000009a81b4>] 0x9a81b4
** 3821 printk messages dropped ** [ 1.673223] [<ffff0000081723ec>] static_key_enable+0x20/0x34
** 4713 printk messages dropped ** [ 1.682006] [<00000000009a81b4>] 0x9a81b4
** 3821 printk messages dropped ** [ 1.689128] [<ffff0000081723ec>] static_key_enable+0x20/0x34
** 4713 printk messages dropped ** [ 1.697911] [<00000000009a81b4>] 0x9a81b4
** 3820 printk messages dropped ** [ 1.705033] [<ffff000008172370>] static_key_slow_inc+0xc8/0x124
** 4854 printk messages dropped ** [ 1.714082] [<ffff0000080eacb4>] dequeue_task_idle+0x24/0x38
** 4711 printk messages dropped ** [ 1.722868] [<ffff0000089a0260>] rwsem_down_read_failed+0xdc/0x108
** 4998 printk messages dropped ** [ 1.732185] [<ffff000008831140>] arch_timer_check_ool_workaround+0xc8/0x1fc
** 5419 printk messages dropped ** [ 1.742283] Hardware name: HiKey960 (DT)
** 3773 printk messages dropped ** [ 1.749320] [<ffff000008172370>] static_key_slow_inc+0xc8/0x124
** 4856 printk messages dropped ** [ 1.758369] [<ffff00000899cfec>] __schedule+0x244/0x5c4
** 4477 printk messages dropped ** [ 1.766714] [<00000000009a81b4>] 0x9a81b4
** 3821 printk messages dropped ** [ 1.773834] [<ffff0000081723ec>] static_key_enable+0x20/0x34
** 4713 printk messages dropped ** [ 1.782619] [<00000000009a81b4>] 0x9a81b4
** 3820 printk messages dropped ** [ 1.789743] [<ffff000008172370>] static_key_slow_inc+0xc8/0x124
** 4857 printk messages dropped ** [ 1.798790] [<ffff00000899d3a4>] schedule+0x38/0x9c
** 4290 printk messages dropped ** [ 1.806785] [<ffff0000089a0260>] rwsem_down_read_failed+0xdc/0x108
** 4995 printk messages dropped ** [ 1.816100] [<ffff0000080c1e44>] cpus_read_lock+0x70/0x74
** 4574 printk messages dropped ** [ 1.824627] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4811 printk messages dropped ** [ 1.833590] [<ffff000008989e70>] dump_stack+0x90/0xb0
** 4385 printk messages dropped ** [ 1.841760] [<ffff000008172370>] static_key_slow_inc+0xc8/0x124
** 4856 printk messages dropped ** [ 1.850811] [<ffff00000899cfec>] __schedule+0x244/0x5c4
** 4476 printk messages dropped ** [ 1.859155] [<ffff00000808e9d0>] secondary_start_kernel+0xb0/0x118
** 4997 printk messages dropped ** [ 1.868468] Hardware name: HiKey960 (DT)
** 3771 printk messages dropped ** [ 1.875501] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4810 printk messages dropped ** [ 1.884467] [<ffff000008088590>] show_stack+0x14/0x1c
** 4383 printk messages dropped ** [ 1.892638] [<ffff0000089a0260>] rwsem_down_read_failed+0xdc/0x108
** 4997 printk messages dropped ** [ 1.901951] [<ffff0000081723ec>] static_key_enable+0x20/0x34
** 4713 printk messages dropped ** [ 1.910736] [<00000000009a81b4>] 0x9a81b4
** 3822 printk messages dropped ** [ 1.917857] [<ffff000008831140>] arch_timer_check_ool_workaround+0xc8/0x1fc
** 5423 printk messages dropped ** [ 1.927961] [<ffff000008989e70>] dump_stack+0x90/0xb0
** 4386 printk messages dropped ** [ 1.936135] [<ffff0000081723ec>] static_key_enable+0x20/0x34
** 4713 printk messages dropped ** [ 1.944918] [<00000000009a81b4>] 0x9a81b4
** 3819 printk messages dropped ** [ 1.952036] [<ffff0000080c1e44>] cpus_read_lock+0x70/0x74
** 4575 printk messages dropped ** [ 1.960563] [<ffff0000080c1e44>] cpus_read_lock+0x70/0x74
** 4569 printk messages dropped ** [ 1.969080] [<ffff0000080eacb4>] dequeue_task_idle+0x24/0x38
** 4713 printk messages dropped ** [ 1.977869] [<ffff0000080c1e44>] cpus_read_lock+0x70/0x74
** 4572 printk messages dropped ** [ 1.986395] [<ffff00000899d3a4>] schedule+0x38/0x9c
** 4291 printk messages dropped ** [ 1.994392] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4810 printk messages dropped ** [ 2.003355] [<ffff000008088590>] show_stack+0x14/0x1c
** 4385 printk messages dropped ** [ 2.011528] [<ffff0000080c1e44>] cpus_read_lock+0x70/0x74
** 4572 printk messages dropped ** [ 2.020048] [<ffff00000899d3a4>] schedule+0x38/0x9c
** 4291 printk messages dropped ** [ 2.028045] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4810 printk messages dropped ** [ 2.037012] [<ffff000008088590>] show_stack+0x14/0x1c
** 4385 printk messages dropped ** [ 2.045184] [<ffff0000080c1e44>] cpus_read_lock+0x70/0x74
** 4573 printk messages dropped ** [ 2.053709] [<ffff0000089a0260>] rwsem_down_read_failed+0xdc/0x108
** 4998 printk messages dropped ** [ 2.063026] [<ffff000008831140>] arch_timer_check_ool_workaround+0xc8/0x1fc
** 5425 printk messages dropped ** [ 2.073128] [<ffff0000080e53f8>] deactivate_task+0x70/0xac
** 4620 printk messages dropped ** [ 2.081738] [<ffff00000899cfec>] __schedule+0x244/0x5c4
** 4478 printk messages dropped ** [ 2.090083] bad: scheduling from the idle thread!
** 4196 printk messages dropped ** [ 2.097910] [<ffff000008831584>] arch_timer_starting_cpu+0xf8/0x2c4
** 5044 printk messages dropped ** [ 2.107306] Hardware name: HiKey960 (DT)
** 3771 printk messages dropped ** [ 2.114340] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4810 printk messages dropped ** [ 2.123304] [<ffff000008088590>] show_stack+0x14/0x1c
** 4383 printk messages dropped ** [ 2.131475] [<ffff0000089a0260>] rwsem_down_read_failed+0xdc/0x108
** 4998 printk messages dropped ** [ 2.140793] [<ffff000008831140>] arch_timer_check_ool_workaround+0xc8/0x1fc
** 5424 printk messages dropped ** [ 2.150895] [<ffff0000080eacb4>] dequeue_task_idle+0x24/0x38
** 4715 printk messages dropped ** [ 2.159680] [<ffff0000081723ec>] static_key_enable+0x20/0x34
** 4716 printk messages dropped ** [ 2.168467] Hardware name: HiKey960 (DT)
** 3771 printk messages dropped ** [ 2.175497] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4804 printk messages dropped ** [ 2.184458] [<00000000009a81b4>] 0x9a81b4
** 3823 printk messages dropped ** [ 2.191583] [<ffff000008831584>] arch_timer_starting_cpu+0xf8/0x2c4
** 5041 printk messages dropped ** [ 2.200979] [<00000000009a81b4>] 0x9a81b4
** 3821 printk messages dropped ** [ 2.208105] [<ffff0000081723ec>] static_key_enable+0x20/0x34
** 4713 printk messages dropped ** [ 2.216886] [<00000000009a81b4>] 0x9a81b4
** 3819 printk messages dropped ** [ 2.224004] [<ffff0000080c1e44>] cpus_read_lock+0x70/0x74
** 4574 printk messages dropped ** [ 2.232530] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4807 printk messages dropped ** [ 2.241489] Hardware name: HiKey960 (DT
We found the mainline arm64 kernel boot failure on Hikey960 board,
this is caused by patch f2545b2d4ce1 (jump_label: Reorder hotplug lock
and jump_label_lock), this patch adds locking cpus_read_lock() in
function static_key_slow_inc() and introduce the dead lock issue by
acquiring lock twice. Below are detailed flow:
arch_timer_register()
`> cpuhp_setup_state()
`> __cpuhp_setup_state()
cpus_read_lock()
`> __cpuhp_setup_state_cpuslocked()
`> cpuhp_issue_call()
`> arch_timer_starting_cpu()
`> __arch_timer_setup()
`> arch_timer_check_ool_workaround()
`> arch_timer_enable_workaround()
`> static_branch_enable()
`> static_key_enable()
`> static_key_slow_inc()
`> cpus_read_lock()
So finally there have called cpus_read_lock() twice, and kernel report
log as below. So I am not sure what's the best way to fix this issue,
could you give some suggestion for this? Thanks.
---8<---
** 510118 printk messages dropped ** [ 1.299405] [<ffff000008831140>] arch_timer_check_ool_workaround+0xc8/0x1fc
** 5516 printk messages dropped ** [ 1.309965] [<ffff00000899d3a4>] schedule+0x38/0x9c
** 4289 printk messages dropped ** [ 1.317961] [<ffff00000899d3a4>] schedule+0x38/0x9c
** 4293 printk messages dropped ** [ 1.325961] [<ffff000008172370>] static_key_slow_inc+0xc8/0x124
** 4857 printk messages dropped ** [ 1.335010] [<ffff00000899d3a4>] schedule+0x38/0x9c
** 4290 printk messages dropped ** [ 1.343008] [<ffff0000089a0260>] rwsem_down_read_failed+0xdc/0x108
** 4999 printk messages dropped ** [ 1.352325] [<ffff000008831584>] arch_timer_starting_cpu+0xf8/0x2c4
** 5048 printk messages dropped ** [ 1.361726] [<ffff000008989e70>] dump_stack+0x90/0xb0
** 4381 printk messages dropped ** [ 1.369892] [<ffff00000899d3a4>] schedule+0x38/0x9c
** 4291 printk messages dropped ** [ 1.377895] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4811 printk messages dropped ** [ 1.386856] [<ffff000008989e70>] dump_stack+0x90/0xb0
** 4384 printk messages dropped ** [ 1.395026] [<ffff0000080c1e44>] cpus_read_lock+0x70/0x74
** 4575 printk messages dropped ** [ 1.403553] [<ffff0000080c1e44>] cpus_read_lock+0x70/0x74
** 4572 printk messages dropped ** [ 1.412071] [<ffff00000899d3a4>] schedule+0x38/0x9c
** 4291 printk messages dropped ** [ 1.420070] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4812 printk messages dropped ** [ 1.429034] [<ffff0000080eacb4>] dequeue_task_idle+0x24/0x38
** 4714 printk messages dropped ** [ 1.437821] [<ffff000008172370>] static_key_slow_inc+0xc8/0x124
** 4855 printk messages dropped ** [ 1.446871] [<ffff0000080e53f8>] deactivate_task+0x70/0xac
** 4620 printk messages dropped ** [ 1.455480] [<ffff00000899cfec>] __schedule+0x244/0x5c4
** 4480 printk messages dropped ** [ 1.463828] Hardware name: HiKey960 (DT)
** 3771 printk messages dropped ** [ 1.470855] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4808 printk messages dropped ** [ 1.479815] Call trace:
** 2965 printk messages dropped ** [ 1.485352] [<00000000009a81b4>] 0x9a81b4
** 3818 printk messages dropped ** [ 1.492473] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4808 printk messages dropped ** [ 1.501436] Call trace:
** 2968 printk messages dropped ** [ 1.506971] Hardware name: HiKey960 (DT)
** 3769 printk messages dropped ** [ 1.514005] [<ffff00000899d3a4>] schedule+0x38/0x9c
** 4288 printk messages dropped ** [ 1.522001] [<ffff00000899cfec>] __schedule+0x244/0x5c4
** 4473 printk messages dropped ** [ 1.530347] [<ffff000008831584>] arch_timer_starting_cpu+0xf8/0x2c4
** 5041 printk messages dropped ** [ 1.539747] [<00000000009a81b4>] 0x9a81b4
** 3819 printk messages dropped ** [ 1.546867] [<ffff0000080c1e44>] cpus_read_lock+0x70/0x74
** 4572 printk messages dropped ** [ 1.555393] [<ffff00000899d3a4>] schedule+0x38/0x9c
** 4288 printk messages dropped ** [ 1.563390] [<ffff00000899cfec>] __schedule+0x244/0x5c4
** 4473 printk messages dropped ** [ 1.571734] [<ffff000008831584>] arch_timer_starting_cpu+0xf8/0x2c4
** 5043 printk messages dropped ** [ 1.581138] CPU: 4 PID: 0 Comm: swapper/4 Tainted: G S W 4.13.0-rc1-linaro-hikey960+ #30
** 6551 printk messages dropped ** [ 1.593352] [<ffff0000080c3640>] notify_cpu_starting+0x68/0x88
** 4807 printk messages dropped ** [ 1.602312] [<ffff00000899cfec>] __schedule+0x244/0x5c4
** 4476 printk messages dropped ** [ 1.610663] [<ffff00000808e9d0>] secondary_start_kernel+0xb0/0x118
** 4996 printk messages dropped ** [ 1.619972] CPU: 4 PID: 0 Comm: swapper/4 Tainted: G S W 4.13.0-rc1-linaro-hikey960+ #30
** 6553 printk messages dropped ** [ 1.632182] [<00000000009a81b4>] 0x9a81b4
** 3820 printk messages dropped ** [ 1.639301] [<ffff000008172370>] static_key_slow_inc+0xc8/0x124
** 4854 printk messages dropped ** [ 1.648349] [<ffff0000080eacb4>] dequeue_task_idle+0x24/0x38
** 4712 printk messages dropped ** [ 1.657139] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4804 printk messages dropped ** [ 1.666098] [<00000000009a81b4>] 0x9a81b4
** 3821 printk messages dropped ** [ 1.673223] [<ffff0000081723ec>] static_key_enable+0x20/0x34
** 4713 printk messages dropped ** [ 1.682006] [<00000000009a81b4>] 0x9a81b4
** 3821 printk messages dropped ** [ 1.689128] [<ffff0000081723ec>] static_key_enable+0x20/0x34
** 4713 printk messages dropped ** [ 1.697911] [<00000000009a81b4>] 0x9a81b4
** 3820 printk messages dropped ** [ 1.705033] [<ffff000008172370>] static_key_slow_inc+0xc8/0x124
** 4854 printk messages dropped ** [ 1.714082] [<ffff0000080eacb4>] dequeue_task_idle+0x24/0x38
** 4711 printk messages dropped ** [ 1.722868] [<ffff0000089a0260>] rwsem_down_read_failed+0xdc/0x108
** 4998 printk messages dropped ** [ 1.732185] [<ffff000008831140>] arch_timer_check_ool_workaround+0xc8/0x1fc
** 5419 printk messages dropped ** [ 1.742283] Hardware name: HiKey960 (DT)
** 3773 printk messages dropped ** [ 1.749320] [<ffff000008172370>] static_key_slow_inc+0xc8/0x124
** 4856 printk messages dropped ** [ 1.758369] [<ffff00000899cfec>] __schedule+0x244/0x5c4
** 4477 printk messages dropped ** [ 1.766714] [<00000000009a81b4>] 0x9a81b4
** 3821 printk messages dropped ** [ 1.773834] [<ffff0000081723ec>] static_key_enable+0x20/0x34
** 4713 printk messages dropped ** [ 1.782619] [<00000000009a81b4>] 0x9a81b4
** 3820 printk messages dropped ** [ 1.789743] [<ffff000008172370>] static_key_slow_inc+0xc8/0x124
** 4857 printk messages dropped ** [ 1.798790] [<ffff00000899d3a4>] schedule+0x38/0x9c
** 4290 printk messages dropped ** [ 1.806785] [<ffff0000089a0260>] rwsem_down_read_failed+0xdc/0x108
** 4995 printk messages dropped ** [ 1.816100] [<ffff0000080c1e44>] cpus_read_lock+0x70/0x74
** 4574 printk messages dropped ** [ 1.824627] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4811 printk messages dropped ** [ 1.833590] [<ffff000008989e70>] dump_stack+0x90/0xb0
** 4385 printk messages dropped ** [ 1.841760] [<ffff000008172370>] static_key_slow_inc+0xc8/0x124
** 4856 printk messages dropped ** [ 1.850811] [<ffff00000899cfec>] __schedule+0x244/0x5c4
** 4476 printk messages dropped ** [ 1.859155] [<ffff00000808e9d0>] secondary_start_kernel+0xb0/0x118
** 4997 printk messages dropped ** [ 1.868468] Hardware name: HiKey960 (DT)
** 3771 printk messages dropped ** [ 1.875501] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4810 printk messages dropped ** [ 1.884467] [<ffff000008088590>] show_stack+0x14/0x1c
** 4383 printk messages dropped ** [ 1.892638] [<ffff0000089a0260>] rwsem_down_read_failed+0xdc/0x108
** 4997 printk messages dropped ** [ 1.901951] [<ffff0000081723ec>] static_key_enable+0x20/0x34
** 4713 printk messages dropped ** [ 1.910736] [<00000000009a81b4>] 0x9a81b4
** 3822 printk messages dropped ** [ 1.917857] [<ffff000008831140>] arch_timer_check_ool_workaround+0xc8/0x1fc
** 5423 printk messages dropped ** [ 1.927961] [<ffff000008989e70>] dump_stack+0x90/0xb0
** 4386 printk messages dropped ** [ 1.936135] [<ffff0000081723ec>] static_key_enable+0x20/0x34
** 4713 printk messages dropped ** [ 1.944918] [<00000000009a81b4>] 0x9a81b4
** 3819 printk messages dropped ** [ 1.952036] [<ffff0000080c1e44>] cpus_read_lock+0x70/0x74
** 4575 printk messages dropped ** [ 1.960563] [<ffff0000080c1e44>] cpus_read_lock+0x70/0x74
** 4569 printk messages dropped ** [ 1.969080] [<ffff0000080eacb4>] dequeue_task_idle+0x24/0x38
** 4713 printk messages dropped ** [ 1.977869] [<ffff0000080c1e44>] cpus_read_lock+0x70/0x74
** 4572 printk messages dropped ** [ 1.986395] [<ffff00000899d3a4>] schedule+0x38/0x9c
** 4291 printk messages dropped ** [ 1.994392] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4810 printk messages dropped ** [ 2.003355] [<ffff000008088590>] show_stack+0x14/0x1c
** 4385 printk messages dropped ** [ 2.011528] [<ffff0000080c1e44>] cpus_read_lock+0x70/0x74
** 4572 printk messages dropped ** [ 2.020048] [<ffff00000899d3a4>] schedule+0x38/0x9c
** 4291 printk messages dropped ** [ 2.028045] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4810 printk messages dropped ** [ 2.037012] [<ffff000008088590>] show_stack+0x14/0x1c
** 4385 printk messages dropped ** [ 2.045184] [<ffff0000080c1e44>] cpus_read_lock+0x70/0x74
** 4573 printk messages dropped ** [ 2.053709] [<ffff0000089a0260>] rwsem_down_read_failed+0xdc/0x108
** 4998 printk messages dropped ** [ 2.063026] [<ffff000008831140>] arch_timer_check_ool_workaround+0xc8/0x1fc
** 5425 printk messages dropped ** [ 2.073128] [<ffff0000080e53f8>] deactivate_task+0x70/0xac
** 4620 printk messages dropped ** [ 2.081738] [<ffff00000899cfec>] __schedule+0x244/0x5c4
** 4478 printk messages dropped ** [ 2.090083] bad: scheduling from the idle thread!
** 4196 printk messages dropped ** [ 2.097910] [<ffff000008831584>] arch_timer_starting_cpu+0xf8/0x2c4
** 5044 printk messages dropped ** [ 2.107306] Hardware name: HiKey960 (DT)
** 3771 printk messages dropped ** [ 2.114340] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4810 printk messages dropped ** [ 2.123304] [<ffff000008088590>] show_stack+0x14/0x1c
** 4383 printk messages dropped ** [ 2.131475] [<ffff0000089a0260>] rwsem_down_read_failed+0xdc/0x108
** 4998 printk messages dropped ** [ 2.140793] [<ffff000008831140>] arch_timer_check_ool_workaround+0xc8/0x1fc
** 5424 printk messages dropped ** [ 2.150895] [<ffff0000080eacb4>] dequeue_task_idle+0x24/0x38
** 4715 printk messages dropped ** [ 2.159680] [<ffff0000081723ec>] static_key_enable+0x20/0x34
** 4716 printk messages dropped ** [ 2.168467] Hardware name: HiKey960 (DT)
** 3771 printk messages dropped ** [ 2.175497] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4804 printk messages dropped ** [ 2.184458] [<00000000009a81b4>] 0x9a81b4
** 3823 printk messages dropped ** [ 2.191583] [<ffff000008831584>] arch_timer_starting_cpu+0xf8/0x2c4
** 5041 printk messages dropped ** [ 2.200979] [<00000000009a81b4>] 0x9a81b4
** 3821 printk messages dropped ** [ 2.208105] [<ffff0000081723ec>] static_key_enable+0x20/0x34
** 4713 printk messages dropped ** [ 2.216886] [<00000000009a81b4>] 0x9a81b4
** 3819 printk messages dropped ** [ 2.224004] [<ffff0000080c1e44>] cpus_read_lock+0x70/0x74
** 4574 printk messages dropped ** [ 2.232530] [<ffff0000080ffe60>] __percpu_down_read+0xfc/0x110
** 4807 printk messages dropped ** [ 2.241489] Hardware name: HiKey960 (DT