Re: console: lockup on boot

From: Peter Hurley
Date: Fri May 30 2014 - 09:58:32 EST


On 05/30/2014 09:11 AM, Sasha Levin wrote:
Hi all,

I sometime see lockups when booting my KVM guest with the latest -next kernel,
it basically hangs right when it should start 'init', and after a while I get
the following spew:

[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0

Maybe related to this report: https://lkml.org/lkml/2014/5/30/26
from Jet Chen which was bisected to

commit bafe980f5afc7ccc693fd8c81c8aa5a02fbb5ae0
Author: Jan Kara <jack@xxxxxxx>
AuthorDate: Thu May 22 10:43:35 2014 +1000
Commit: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
CommitDate: Thu May 22 10:43:35 2014 +1000

printk: enable interrupts before calling console_trylock_for_printk()
We need interrupts disabled when calling console_trylock_for_printk() only
so that cpu id we pass to can_use_console() remains valid (for other
things console_sem provides all the exclusion we need and deadlocks on
console_sem due to interrupts are impossible because we use
down_trylock()). However if we are rescheduled, we are guaranteed to run
on an online cpu so we can easily just get the cpu id in
can_use_console().
We can lose a bit of performance when we enable interrupts in
vprintk_emit() and then disable them again in console_unlock() but OTOH it
can somewhat reduce interrupt latency caused by console_unlock()
especially since later in the patch series we will want to spin on
console_sem in console_trylock_for_printk().
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>

?

[ 30.770667] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 30.770667] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 320.541585] kworker/dying (172) used greatest stack depth: 3656 bytes left
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 408.010589] INFO: task swapper/0:1 blocked for more than 200 seconds.
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 321.761422] general protection fault: 0000 [#1]
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 2950.759251] BUG: spinlock lockup suspected on CPU#32, swapper/32/0
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 3109.224481] BUG: spinlock lockup suspected on CPU#32, swapper/32/0
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 3251.771402] BUG: spinlock lockup suspected on CPU#32, swapper/32/0
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 3401.522129] BUG: spinlock lockup suspected on CPU#32, swapper/32/0
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 3568.564422] BUG: spinlock lockup suspected on CPU#32, swapper/32/0
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 3754.638392] BUG: spinlock lockup suspected on CPU#32, swapper/32/0
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 3941.597288] BUG: spinlock lockup suspected on CPU#32, swapper/32/0
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 4114.243312] BUG: spinlock lockup suspected on CPU#32, swapper/32/0
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 4287.428963] BUG: spinlock lockup suspected on CPU#32, swapper/32/0
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 30.790833] BUG: spinlock lockup suspected on CPU#1, swapper/1/0
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 320.551104] BUG: spinlock lockup suspected on CPU#33, kworker/dying/172
[ 4458.566115] BUG: spinlock lockup suspected on CPU#32, swapper/32/0
[ 408.020558] BUG: spinlock lockup suspected on CPU#43, khungtaskd/3760
[ 30.790833] PANIC: double fault, error_code: 0x0
[ 320.551104] lock: console_sem+0x0/0x60, .magic: dead4ead, .owner: kworker/u101:1/484, .owner_cpu: -1
[ 408.020558] lock: console_sem+0x0/0x60, .magic: dead4ead, .owner: kworker/u101:1/484, .owner_cpu: 33
[ 321.761422] lock: console_sem+0x0/0x60, .magic: dead4ead, .owner: kworker/u101:1/484, .owner_cpu: -1
[ 320.551104] CPU: 33 PID: 172 Comm: kworker/dying Tainted: G W 3.15.0-rc7-next-20140529-sasha-00017-gd239c90-dirty #550
[ 320.551104] ffffffff8e087060 ffff88012a800b38 ffffffff8c4e92e3 0000000000000001
[ 30.790833] ffff88007bdd3000
[ 30.790833] CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 3.15.0-rc7-next-20140529-sasha-00017-gd239c90-dirty #550
[ 30.790833] ffff88012a800b58
[ 30.790833] task: ffff880a2b3f0000 ti: ffff88007c1d0000 task.ti: ffff88007c1d0000
[ 30.790833] ffffffff8c4dc9fe
[ 320.551104] RIP: (??:?)
[ 320.551104] ffffffff8e087060
[ 30.790833] 0000000086c41770
[ 30.790833] string.isra.5 (lib/vsprintf.c:506)
[ 30.790833] ffff88012a800b88
[ 30.790833] RSP: 0000:ffff88012ba00000 EFLAGS: 00010092
[ 30.790833] ffffffff891d08b4
[ 30.790833] RAX: ffffffff8d6ee711 RBX: ffffffff906949f0 RCX: 0000000000000000
[ 30.790833] ffffffff8e087078
[ 30.790833] RDX: ffffffff8d6eb246 RSI: ffffffffffffffff RDI: ffffffff906949f0
[ 320.551104]
[ 30.790833] RBP: ffff88012ba00018 R08: 000000000000ffff R09: 000000000000ffff
[ 320.551104] Call Trace:
[ 30.790833] R10: 73203a4755423001 R11: 206b636f6c6e6970 R12: ffffffff90694dc0
[ 30.790833] R13: ffffffff90694dc0 R14: 000000000000ffff R15: 0000000000000000
[ 30.790833] <UNK>
[ 30.790833] FS: 0000000000000000(0000) GS:ffff88012ba00000(0000) knlGS:0000000000000000
[ 321.761422] CPU: 0 PID: 484 Comm: kworker/u101:1 Tainted: G W 3.15.0-rc7-next-20140529-sasha-00017-gd239c90-dirty #550
[ 30.790833] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 320.551104] sending NMI to all CPUs:
[ 30.790833] CR2: ffff88012b9ffff8 CR3: 000000000e02c000 CR4: 00000000000006a0
[ 321.761422] BUG: spinlock lockup suspected on CPU#0, kworker/u101:1/484
[ 321.761422] lock: logbuf_lock+0x0/0x48, .magic: dead4ead, .owner: kworker/u101:1/484, .owner_cpu: -1
[ 321.761422] CPU: 0 PID: 484 Comm: kworker/u101:1 Tainted: G W 3.15.0-rc7-next-20140529-sasha-00017-gd239c90-dirty #550
[ 321.761422] Workqueue: events_power_efficient fb_flashcursor
[ 321.761422] ffffffff8e087000 ffff88007da06c78 ffffffff8c4e92e3 0000000000000000
[ 321.761422] ffff88007bdd3000 ffff88007da06c98 ffffffff8c4dc9fe ffffffff8e087000
[ 321.761422] 0000000086c41770 ffff88007da06cc8 ffffffff891d08b4 ffffffff8e087018
[ 321.761422] Call Trace:
[ 321.761422] <NMI> dump_stack (lib/dump_stack.c:52)
[ 321.761422] spin_dump (kernel/locking/spinlock_debug.c:68 (discriminator 6))
[ 321.761422] do_raw_spin_lock (include/linux/nmi.h:35 kernel/locking/spinlock_debug.c:119 kernel/locking/spinlock_debug.c:137)
[ 321.761422] _raw_spin_lock (include/linux/spinlock_api_smp.h:143 kernel/locking/spinlock.c:151)
[ 321.761422] ? vprintk_emit (kernel/printk/printk.c:1620)
[ 321.761422] vprintk_emit (kernel/printk/printk.c:1620)
[ 321.761422] printk (kernel/printk/printk.c:1806)
[ 321.761422] arch_trigger_all_cpu_backtrace_handler (arch/x86/kernel/apic/hw_nmi.c:85)
[ 321.761422] nmi_handle (arch/x86/kernel/nmi.c:133)
[ 321.761422] ? nmi_handle (arch/x86/kernel/nmi.c:114)
[ 321.761422] default_do_nmi (arch/x86/kernel/nmi.c:336)
[ 321.761422] ? get_color.isra.12 (drivers/video/console/fbcon.c:369)
[ 321.761422] do_nmi (./arch/x86/include/asm/current.h:14 arch/x86/kernel/nmi.c:540)
[ 321.761422] end_repeat_nmi (arch/x86/kernel/entry_64.S:1701)
[ 321.761422] ? get_color.isra.12 (drivers/video/console/fbcon.c:369)
[ 321.761422] ? get_color.isra.12 (drivers/video/console/fbcon.c:369)
[ 321.761422] ? get_symbol_pos (kernel/kallsyms.c:230)
[ 321.761422] ? get_symbol_pos (kernel/kallsyms.c:230)
[ 321.761422] ? get_symbol_pos (kernel/kallsyms.c:230)
[ 321.761422] <<EOE>> <UNK>
[ 321.761422] NMI backtrace for cpu 0
[ 321.761422] CPU: 0 PID: 484 Comm: kworker/u101:1 Tainted: G W 3.15.0-rc7-next-20140529-sasha-00017-gd239c90-dirty #550
[ 321.761422] Workqueue: events_power_efficient fb_flashcursor
[ 321.761422] task: ffff88007bdd3000 ti: ffff88007bde8000 task.ti: ffff88007bde8000
[ 321.761422] RIP: get_symbol_pos (kernel/kallsyms.c:230)
[ 321.761422] RSP: 0000:ffff88007bde5c78 EFLAGS: 00000006
[ 321.761422] RAX: 0000000000008c7c RBX: ffff88007bde5cd0 RCX: 0000000000009831
[ 321.761422] RDX: ffff88007bde5cd8 RSI: ffff88007bde5ce0 RDI: ffffffff89bba9c0
[ 321.761422] RBP: ffff88007bde5c78 R08: 000000000000a3e6 R09: 000000000000ffff
[ 321.761422] R10: 000000000005da8d R11: 3a6d6d6f43203438 R12: ffff88007bde5d41
[ 321.761422] R13: ffffffff89bba9c0 R14: 0000000000000000 R15: ffffffff8d6e8c47
[ 321.761422] FS: 0000000000000000(0000) GS:ffff88007da00000(0000) knlGS:0000000000000000
[ 321.761422] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 321.761422] CR2: 00000000ffffffff CR3: 000000000e02c000 CR4: 00000000000006b0
[ 321.761422] Stack:
[ 321.761422] ffff88007bde5cb8 ffffffff8920eb4e 70202c786c383025 ffff88007bde5e31
[ 321.761422] ffff8800fbde5e2b ffff88007bde5d41 ffffffff89bba9c0 0000000000000000
[ 321.761422] ffff88007bde5d08 ffffffff8920ec42 522829676e6fffff 296e656c3e2d4345
[ 321.761422] Call Trace:
[ 321.761422] <UNK>
[ 321.761422] Code: 30 0e f7 8c 55 48 85 c0 48 89 e5 75 02 0f 0b 4c 8b 15 ca fc 04 04 31 c0 4d 89 d0 eb 16 48 d1 e9 48 01 c1 48 39 3c cd 30 0e f7 8c <4c> 0f 47 c1 48 0f 46 c1 4c 89 c1 48 29 c1 48 83 f9 01 77 de 48
All code
========
0: 30 0e xor %cl,(%rsi)
2: f7 (bad)
3: 8c 55 48 mov %ss,0x48(%rbp)
6: 85 c0 test %eax,%eax
8: 48 89 e5 mov %rsp,%rbp
b: 75 02 jne 0xf
d: 0f 0b ud2
f: 4c 8b 15 ca fc 04 04 mov 0x404fcca(%rip),%r10 # 0x404fce0
16: 31 c0 xor %eax,%eax
18: 4d 89 d0 mov %r10,%r8
1b: eb 16 jmp 0x33
1d: 48 d1 e9 shr %rcx
20: 48 01 c1 add %rax,%rcx
23: 48 39 3c cd 30 0e f7 cmp %rdi,-0x7308f1d0(,%rcx,8)
2a: 8c
2b:* 4c 0f 47 c1 cmova %rcx,%r8 <-- trapping instruction
2f: 48 0f 46 c1 cmovbe %rcx,%rax
33: 4c 89 c1 mov %r8,%rcx
36: 48 29 c1 sub %rax,%rcx
39: 48 83 f9 01 cmp $0x1,%rcx
3d: 77 de ja 0x1d
3f: 48 rex.W
...

Code starting with the faulting instruction
===========================================
0: 4c 0f 47 c1 cmova %rcx,%r8
4: 48 0f 46 c1 cmovbe %rcx,%rax
8: 4c 89 c1 mov %r8,%rcx
b: 48 29 c1 sub %rax,%rcx
e: 48 83 f9 01 cmp $0x1,%rcx
12: 77 de ja 0xfffffffffffffff2
14: 48 rex.W
...
[ 30.790833] NMI backtrace for cpu 1
[hang]


Thanks,
Sasha
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