My tests triggered this splat on 4.13-rc1:
Loading iSCSI transport class v2.0-870.
QLogic NetXtreme II iSCSI Driver bnx2i v2.7.10.1 (Jul 16, 2014)
iscsi: registered transport (bnx2i)
============================================
WARNING: possible recursive locking detected
4.13.0-rc1-test+ #2 Not tainted
--------------------------------------------
swapper/0/1 is trying to acquire lock:
(cpu_hotplug_lock.rw_sem){++++++}, at: [<ffffffffb505329e>]
__cpuhp_setup_state+0x28/0x59
but task is already holding lock:
(cpu_hotplug_lock.rw_sem){++++++}, at: [<ffffffffb64d54e9>]
bnx2i_mod_init+0x134/0x209
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(cpu_hotplug_lock.rw_sem);
lock(cpu_hotplug_lock.rw_sem);
*** DEADLOCK ***
May be due to missing lock nesting notation
1 lock held by swapper/0/1:
#0: (cpu_hotplug_lock.rw_sem){++++++}, at: [<ffffffffb64d54e9>]
bnx2i_mod_init+0x134/0x209
stack backtrace:
CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.13.0-rc1-test+ #2
Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 02/22/2014
Call Trace:
dump_stack+0x68/0x92
__lock_acquire+0x84b/0xebb
? __lock_is_held+0x47/0x7a
? mark_held_locks+0x5e/0x74
? _raw_spin_unlock_irqrestore+0x40/0x47
lock_acquire+0x108/0x19c
? lock_acquire+0x108/0x19c
? __cpuhp_setup_state+0x28/0x59
cpus_read_lock+0x2f/0x5f
? __cpuhp_setup_state+0x28/0x59
__cpuhp_setup_state+0x28/0x59
? bnx2i_percpu_thread_create+0x79/0x79
bnx2i_mod_init+0x17a/0x209
? iscsi_transport_init+0x1c1/0x1c1
? set_debug_rodata+0x17/0x17
do_one_initcall+0x90/0x131
? set_debug_rodata+0x17/0x17
kernel_init_freeable+0x1e5/0x26d
? rest_init+0xd8/0xd8
kernel_init+0xe/0xfa
ret_from_fork+0x27/0x40
ahci 0000:00:1f.2: version 3.0
ahci 0000:00:1f.2: AHCI 0001.0300 32 slots 6 ports 6 Gbps 0x3 impl SATA mode
ahci 0000:00:1f.2: flags: 64bit ncq led clo pio slum part ems apst
scsi host0: ahci
I'd let the powers that be figure it out.
-- Steve
