Re: Locking Problem in 2.6.33-rc5

From: Larry Finger
Date: Tue Jan 26 2010 - 13:50:39 EST


On 01/26/2010 12:25 PM, Rafael J. Wysocki wrote:
On Tuesday 26 January 2010, Larry Finger wrote:
On suspend to RAM, I get the following recursive locking message:

=============================================
[ INFO: possible recursive locking detected ]
2.6.33-rc5-Linus-dirty #173
---------------------------------------------
sh/3488 is trying to acquire lock:
(s_active){++++.+}, at: [<ffffffff81167413>] sysfs_addrm_finish+0x43/0x70

but task is already holding lock:
(s_active){++++.+}, at: [<ffffffff8116771d>] sysfs_get_active_two+0x3d/0x60

other info that might help us debug this:
4 locks held by sh/3488:
#0: (&buffer->mutex){+.+.+.}, at: [<ffffffff81165b7f>]
sysfs_write_file+0x3f/0x160
#1: (s_active){++++.+}, at: [<ffffffff8116771d>] sysfs_get_active_two+0x3d/0x60
#2: (s_active){++++.+}, at: [<ffffffff81167702>] sysfs_get_active_two+0x22/0x60
#3: (dbs_mutex){+.+.+.}, at: [<ffffffff81271517>]
cpufreq_governor_dbs+0xe7/0x480

stack backtrace:
Pid: 3488, comm: sh Not tainted 2.6.33-rc5-Linus-dirty #173
Call Trace:
[<ffffffff8107c36b>] __lock_acquire+0xf6b/0x1d30
[<ffffffff81078e9f>] ? lockdep_init_map+0x5f/0x5d0
[<ffffffff8107d1cb>] lock_acquire+0x9b/0x120
[<ffffffff81167413>] ? sysfs_addrm_finish+0x43/0x70
[<ffffffff81166ba3>] sysfs_deactivate+0xc3/0x110
[<ffffffff81167413>] ? sysfs_addrm_finish+0x43/0x70
[<ffffffff81167413>] sysfs_addrm_finish+0x43/0x70
[<ffffffff81165206>] sysfs_hash_and_remove+0x56/0x80
[<ffffffff8116895f>] sysfs_remove_group+0x4f/0xf0
[<ffffffff8127152b>] cpufreq_governor_dbs+0xfb/0x480
[<ffffffff8107a8dd>] ? trace_hardirqs_on_caller+0x14d/0x190
[<ffffffff8107a92d>] ? trace_hardirqs_on+0xd/0x10
[<ffffffff8126e314>] __cpufreq_governor+0x94/0x160
[<ffffffff8126f84f>] __cpufreq_set_policy+0x11f/0x180
[<ffffffff8126fc66>] store_scaling_governor+0xc6/0x200
[<ffffffff81270530>] ? handle_update+0x0/0x10
[<ffffffff8126f702>] store+0x62/0x90
[<ffffffff81165c21>] sysfs_write_file+0xe1/0x160
[<ffffffff8110b0c8>] vfs_write+0xb8/0x180
[<ffffffff8110b26c>] sys_write+0x4c/0x80
[<ffffffff81002dab>] system_call_fastpath+0x16/0x1b

Does the patch at http://patchwork.kernel.org/patch/70461/ fix it?

No, it does not. The traceback is identical except for the new kernel compilation number.

Larry


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/