On Mon, Feb 27, 2017 at 11:28:24AM +0100, Peter Zijlstra wrote:
> On Mon, Feb 27, 2017 at 01:14:09PM +0800, Fengguang Wu wrote:
> > Hello,
> >
> > This bisect result is not satisfactory, however the bug is very
> > reproducible and looks still alive in mainline&linux-next. You may
> > try the attached reproduce-* script to debug it.
>
> OK, let me try that, however, see below.
What that reproduces does is:
[ 17.169056] =====================================
[ 17.171014] [ BUG: bad unlock balance detected! ]
[ 17.172115] 4.10.0-10265-ge5d56ef #18 Not tainted
[ 17.172115] -------------------------------------
[ 17.172115] kworker/u2:0/5 is trying to release lock (ww_class_mutex) at:
[ 17.172115] [<41575474>] ww_mutex_unlock+0x66/0x72
[ 17.172115] but there are no more locks to release!
[ 17.172115]
[ 17.172115] other info that might help us debug this:
[ 17.172115]
[ 17.172115] other info that might help us debug this:
[ 17.172115] 4 locks held by kworker/u2:0/5:
[ 17.172115] #0: ("test-ww_mutex"){......}, at: [<41041def>]
process_one_work+0x168/0x33a
[ 17.172115] #1: ((&stress->work)){......}, at: [<41041def>]
process_one_work+0x168/0x33a
[ 17.172115] #2: (ww_class_acquire){......}, at: [<41041e47>]
process_one_work+0x1c0/0x33a
[ 17.172115] #3: (ww_class_mutex){......}, at: [<41057d98>]
stress_inorder_work+0xbf/0x218
[ 17.172115]
[ 17.172115] stack backtrace:
[ 17.172115]
[ 17.172115] stack backtrace:
[ 17.172115] CPU: 0 PID: 5 Comm: kworker/u2:0 Not tainted
4.10.0-10265-ge5d56ef #18
[ 17.172115] Workqueue: test-ww_mutex stress_inorder_work
[ 17.172115] Call Trace:
[ 17.172115] dump_stack+0x16/0x18
[ 17.172115] print_unlock_imbalance_bug+0xb4/0xc1
[ 17.172115] ? ww_mutex_unlock+0x66/0x72
[ 17.172115] lock_release+0x28d/0x2bb
[ 17.172115] ? ww_mutex_unlock+0x66/0x72
[ 17.172115] __mutex_unlock_slowpath+0x2d/0x1db
[ 17.172115] ? schedule_hrtimeout_range+0xd/0xf
[ 17.172115] mutex_unlock+0xb/0xd
[ 17.172115] ww_mutex_unlock+0x66/0x72
[ 17.172115] stress_inorder_work+0x10a/0x218
[ 17.172115] process_one_work+0x1c0/0x33a
[ 17.172115] ? process_one_work+0x168/0x33a
[ 17.172115] worker_thread+0x22f/0x315
[ 17.172115] kthread+0xed/0xf2
[ 17.172115] ? process_scheduled_works+0x24/0x24
[ 17.172115] ? __kthread_create_on_node+0x11f/0x11f
[ 17.172115] ret_from_fork+0x21/0x30
Which is an entirely different error.. Lemme look into that.
