Hi Jens,
I was about to fix up this splat..
[ 445.022141] loop: module loaded
[ 445.078116] BUG: using smp_processor_id() in preemptible [00000000] code:
loop0/3801
[ 445.085873] caller is debug_smp_processor_id+0x17/0x20
[ 445.091016] CPU: 7 PID: 3801 Comm: loop0 Tainted: G E
4.12.0-default #40
[ 445.098838] Hardware name: IBM System x3550 M3 -[7944K3G]-/69Y5698 ,
BIOS -[D6E150AUS-1.10]- 12/15/2010
[ 445.108564] Call Trace:
[ 445.111016] dump_stack+0x65/0x89
[ 445.114330] check_preemption_disabled+0xde/0xf0
[ 445.118945] debug_smp_processor_id+0x17/0x20
[ 445.123300] blk_stat_add+0xb0/0x130
[ 445.126876] __blk_mq_complete_request+0xb5/0x150
[ 445.131575] blk_mq_complete_request+0x16/0x20
[ 445.136020] loop_queue_work+0x5f/0xaa0 [loop]
[ 445.140461] ? _raw_spin_unlock_irq+0x21/0x40
[ 445.144816] ? finish_task_switch+0x85/0x270
[ 445.149085] ? __schedule+0x291/0x8c0
[ 445.152747] kthread_worker_fn+0xc2/0x1d0
[ 445.156754] kthread+0x114/0x150
[ 445.159983] ? __kthread_init_worker+0xb0/0xb0
[ 445.164424] ? kthread_park+0x60/0x60
[ 445.168085] ret_from_fork+0x2c/0x40
..but then noticed that __blk_mq_run_hw_queue() is also called under
get_cpu(), but recently grew a might_sleep(), so maybe wants some block
layer eyeballs.
-Mike
