2012-10-23 18:12:30

by Maciej Rutecki

Subject: [REGRESSION] 3.7-rc2 [ INFO: suspicious RCU usage. ]

Got during normal boot:
[ 0.748900] ===============================
[ 0.748948] [ INFO: suspicious RCU usage. ]
[ 0.748997] 3.7.0-rc2 #1 Not tainted
[ 0.749045] -------------------------------
[ 0.749094] include/linux/cgroup.h:566 suspicious rcu_dereference_check()
usage!
[ 0.749149]
[ 0.749149] other info that might help us debug this:
[ 0.749149]
[ 0.749207]
[ 0.749207] rcu_scheduler_active = 1, debug_locks = 0
[ 0.749260] 2 locks held by kdevtmpfs/29:
[ 0.749308] #0: (sb_writers){.+.+.+}, at: [<ffffffff81133b22>]
mnt_want_write+0x1f/0x46
[ 0.749570] #1: (&sb->s_type->i_mutex_key#3/1){+.+.+.}, at:
[<ffffffff811250fa>] kern_path_create+0x7e/0x13f
[ 0.749919]
[ 0.749919] stack backtrace:
[ 0.749970] Pid: 29, comm: kdevtmpfs Not tainted 3.7.0-rc2 #1
[ 0.750022] Call Trace:
[ 0.750084] [<ffffffff8108654b>] lockdep_rcu_suspicious+0x109/0x112
[ 0.750152] [<ffffffff811ed588>] task_subsys_state.constprop.6+0x68/0x70
[ 0.750219] [<ffffffff811edce1>] devcgroup_inode_mknod+0x20/0x9b
[ 0.750287] [<ffffffff811d6721>] ? security_capable+0x13/0x15
[ 0.750353] [<ffffffff81049c49>] ? ns_capable+0x48/0x60
[ 0.750418] [<ffffffff811255d0>] vfs_mknod+0x61/0xae
[ 0.750483] [<ffffffff8132ce74>] handle_create.isra.2+0x13f/0x1b0
[ 0.750549] [<ffffffff8132cf8e>] ? devtmpfsd+0xa9/0x156
[ 0.750614] [<ffffffff81088371>] ? lock_release+0x164/0x1aa
[ 0.750679] [<ffffffff8132cee5>] ? handle_create.isra.2+0x1b0/0x1b0
[ 0.750746] [<ffffffff8132cfd3>] devtmpfsd+0xee/0x156
[ 0.750809] [<ffffffff8132cee5>] ? handle_create.isra.2+0x1b0/0x1b0
[ 0.750876] [<ffffffff8105d10a>] kthread+0xac/0xb4
[ 0.750939] [<ffffffff8105d05e>] ? __kthread_parkme+0x60/0x60
[ 0.751006] [<ffffffff814877bc>] ret_from_fork+0x7c/0xb0
[ 0.751070] [<ffffffff8105d05e>] ? __kthread_parkme+0x60/0x60


Last known good kernel: 3.6.1

lspci:
http://mrutecki.pl/download/kernel/3.7-rc2/leon/lspci.txt

dmesg:
http://mrutecki.pl/download/kernel/3.7-rc2/leon/dmesg-3.7-rc2.txt

Regards
--
Maciej Rutecki
http://www.mrutecki.pl

2012-10-29 18:41:07

by Maciej Rutecki

Subject: Re: [REGRESSION] 3.7-rc2 [ INFO: suspicious RCU usage. ]

On wtorek, 23 października 2012 o 20:12:25 Maciej Rutecki wrote:
> Got during normal boot:
> [ 0.748900] ===============================
> [ 0.748948] [ INFO: suspicious RCU usage. ]
> [ 0.748997] 3.7.0-rc2 #1 Not tainted
> [ 0.749045] -------------------------------
> [ 0.749094] include/linux/cgroup.h:566 suspicious
> rcu_dereference_check() usage!
> [ 0.749149]
> [ 0.749149] other info that might help us debug this:
> [ 0.749149]
> [ 0.749207]
> [ 0.749207] rcu_scheduler_active = 1, debug_locks = 0
> [ 0.749260] 2 locks held by kdevtmpfs/29:
> [ 0.749308] #0: (sb_writers){.+.+.+}, at: [<ffffffff81133b22>]
> mnt_want_write+0x1f/0x46
> [ 0.749570] #1: (&sb->s_type->i_mutex_key#3/1){+.+.+.}, at:
> [<ffffffff811250fa>] kern_path_create+0x7e/0x13f
> [ 0.749919]
> [ 0.749919] stack backtrace:
> [ 0.749970] Pid: 29, comm: kdevtmpfs Not tainted 3.7.0-rc2 #1
> [ 0.750022] Call Trace:
> [ 0.750084] [<ffffffff8108654b>] lockdep_rcu_suspicious+0x109/0x112
> [ 0.750152] [<ffffffff811ed588>]
> task_subsys_state.constprop.6+0x68/0x70 [ 0.750219]
> [<ffffffff811edce1>] devcgroup_inode_mknod+0x20/0x9b [ 0.750287]
> [<ffffffff811d6721>] ? security_capable+0x13/0x15
> [ 0.750353] [<ffffffff81049c49>] ? ns_capable+0x48/0x60
> [ 0.750418] [<ffffffff811255d0>] vfs_mknod+0x61/0xae
> [ 0.750483] [<ffffffff8132ce74>] handle_create.isra.2+0x13f/0x1b0
> [ 0.750549] [<ffffffff8132cf8e>] ? devtmpfsd+0xa9/0x156
> [ 0.750614] [<ffffffff81088371>] ? lock_release+0x164/0x1aa
> [ 0.750679] [<ffffffff8132cee5>] ? handle_create.isra.2+0x1b0/0x1b0
> [ 0.750746] [<ffffffff8132cfd3>] devtmpfsd+0xee/0x156
> [ 0.750809] [<ffffffff8132cee5>] ? handle_create.isra.2+0x1b0/0x1b0
> [ 0.750876] [<ffffffff8105d10a>] kthread+0xac/0xb4
> [ 0.750939] [<ffffffff8105d05e>] ? __kthread_parkme+0x60/0x60
> [ 0.751006] [<ffffffff814877bc>] ret_from_fork+0x7c/0xb0
> [ 0.751070] [<ffffffff8105d05e>] ? __kthread_parkme+0x60/0x60
>
>
> Last known good kernel: 3.6.1
>
> lspci:
> http://mrutecki.pl/download/kernel/3.7-rc2/leon/lspci.txt
>
> dmesg:
> http://mrutecki.pl/download/kernel/3.7-rc2/leon/dmesg-3.7-rc2.txt
>
> Regards

It seems that in -rc3 warning has gone.
Regards

--
Maciej Rutecki
http://www.mrutecki.pl