From: Knut Petersen <Knut_Petersen@t-online.de>
To: Shaohua Li <shaohua.li@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Jens Axboe <axboe@kernel.dk>, Tejun Heo <tj@kernel.org>,
linux-kernel@vger.kernel.org
Subject: Re: [BUG 3.3-rc2] spinlock trylock failure on UP on CPU#0
Date: Mon, 06 Feb 2012 08:15:11 +0100 [thread overview]
Message-ID: <4F2F7DFF.5070308@t-online.de> (raw)
In-Reply-To: <CANejiEWBdL4G3qt4=qjzakkokt1xbmcRXFS15EFt3bnSsvkCMA@mail.gmail.com>
Am 06.02.2012 02:25, schrieb Shaohua Li:
> 2012/2/6 Linus Torvalds<torvalds@linux-foundation.org>:
>> Jens, Tejun - the crazy-ass games that this code is playing is clearly
>> messing not just with lockdep, it's messing with some very reasonable
>> spinlock sanity checks on UP (which just boil down to "a spinlock
>> should never have contention on UP")
>>
>> Any chance of sanitizing this all?
> I just sent out a debug patch, please try:
> http://marc.info/?l=linux-kernel&m=132849146702770&w=2
>
Your debug patch helps - but with you patch applied another problem is back again:
3.2.1 ... 3.2.4
===========
dvb-s reception with kaffeine works well, but starting kaffeine
triggers a circular locking dependency warning, see:
http://www.gossamer-threads.com/lists/linux/kernel/1487577
3.3-rc2+ (23783f817bceedd6d4e549385e3f400ea64059e5)
===============================================
spinlock trylock failure on UP on CPU#0 warning is triggered during system startup,
dvb-s with kaffeine is broken (only about 1-2 fps, video frames and audio distorted),
the circular locking dependency warning mentioned above is gone.
3.3-rc2+ (23783f817bceedd6d4e549385e3f400ea64059e5) + blk-icq-lock-fix.patch
=================================================================
spinlock trylock failure warning during system startup is gone,
dvb-s reception with kaffeine is still broken,
the circular locking dependency warning is triggered again by kaffeine:
[ 124.314255]
[ 124.314262] ======================================================
[ 124.314270] [ INFO: possible circular locking dependency detected ]
[ 124.314279] 3.3.0-rc2-main+ #22 Not tainted
[ 124.314285] -------------------------------------------------------
[ 124.314293] kaffeine/3743 is trying to acquire lock:
[ 124.314300] (&fe->lock){+.+.+.}, at: [<f85e70cf>] videobuf_dvb_find_frontend+0x16/0x3e [videobuf_dvb]
[ 124.314320]
[ 124.314321] but task is already holding lock:
[ 124.314327] (minor_rwsem#2){++++..}, at: [<f8e430c8>] dvb_device_open+0x24/0x185 [dvb_core]
[ 124.314348]
[ 124.314349] which lock already depends on the new lock.
[ 124.314351]
[ 124.314359]
[ 124.314360] the existing dependency chain (in reverse order) is:
[ 124.314369]
[ 124.314370] -> #2 (minor_rwsem#2){++++..}:
[ 124.314382] [<c0149609>] lock_acquire+0x45/0x5c
[ 124.314394] [<c0441070>] down_write+0x1b/0x36
[ 124.314405] [<f8e43521>] dvb_register_device+0x113/0x1ed [dvb_core]
[ 124.314420] [<f8e4b320>] dvb_register_frontend+0x172/0x19e [dvb_core]
[ 124.314437] [<f85e7266>] videobuf_dvb_register_bus+0xbe/0x2cb [videobuf_dvb]
[ 124.314450] [<f86d0c9e>] cx8802_dvb_probe+0x1eac/0x1f22 [cx88_dvb]
[ 124.314464] [<f857a420>] cx8802_register_driver+0x116/0x1cc [cx8802]
[ 124.314479] [<f8ce701c>] 0xf8ce701c
[ 124.314490] [<c0101070>] do_one_initcall+0x70/0x118
[ 124.314500] [<c01504d1>] sys_init_module+0x12a3/0x1543
[ 124.314510] [<c0442bf5>] syscall_call+0x7/0xb
[ 124.314520]
[ 124.314521] -> #1 (dvbdev_register_lock){+.+.+.}:
[ 124.314532] [<c0149609>] lock_acquire+0x45/0x5c
[ 124.314541] [<c0440b37>] mutex_lock_nested+0x35/0x275
[ 124.314550] [<f8e4342d>] dvb_register_device+0x1f/0x1ed [dvb_core]
[ 124.314564] [<f8e439a5>] dvb_dmxdev_init+0xc0/0xf0 [dvb_core]
[ 124.314577] [<f85e7311>] videobuf_dvb_register_bus+0x169/0x2cb [videobuf_dvb]
[ 124.314589] [<f86d0c9e>] cx8802_dvb_probe+0x1eac/0x1f22 [cx88_dvb]
[ 124.314601] [<f857a420>] cx8802_register_driver+0x116/0x1cc [cx8802]
[ 124.314612] [<f8ce701c>] 0xf8ce701c
[ 124.314620] [<c0101070>] do_one_initcall+0x70/0x118
[ 124.314629] [<c01504d1>] sys_init_module+0x12a3/0x1543
[ 124.314638] [<c0442bf5>] syscall_call+0x7/0xb
[ 124.314647]
[ 124.314648] -> #0 (&fe->lock){+.+.+.}:
[ 124.314658] [<c0148d54>] __lock_acquire+0xd88/0x12b8
[ 124.314667] [<c0149609>] lock_acquire+0x45/0x5c
[ 124.314675] [<c0440b37>] mutex_lock_nested+0x35/0x275
[ 124.314684] [<f85e70cf>] videobuf_dvb_find_frontend+0x16/0x3e [videobuf_dvb]
[ 124.314695] [<f86ced7a>] cx88_dvb_bus_ctrl+0x22/0x9a [cx88_dvb]
[ 124.314707] [<f8e4982f>] dvb_frontend_open+0x14b/0x2ee [dvb_core]
[ 124.314722] [<f8e43173>] dvb_device_open+0xcf/0x185 [dvb_core]
[ 124.314735] [<c0194f15>] chrdev_open+0x14e/0x16c
[ 124.314754] [<c019056b>] __dentry_open+0x193/0x288
[ 124.314768] [<c01913a9>] nameidata_to_filp+0x42/0x50
[ 124.314780] [<c019c89b>] do_last+0x6db/0x6ed
[ 124.314793] [<c019c973>] path_openat+0xa1/0x2c2
[ 124.314805] [<c019cc40>] do_filp_open+0x21/0x5d
[ 124.314818] [<c01914a5>] do_sys_open+0xee/0x167
[ 124.314830] [<c019153d>] sys_open+0x1f/0x27
[ 124.314842] [<c0442bf5>] syscall_call+0x7/0xb
[ 124.314855]
[ 124.314856] other info that might help us debug this:
[ 124.314857]
[ 124.314876] Chain exists of:
[ 124.314877] &fe->lock --> dvbdev_register_lock --> minor_rwsem#2
[ 124.314896]
[ 124.314906] Possible unsafe locking scenario:
[ 124.314908]
[ 124.314921] CPU0 CPU1
[ 124.314931] ---- ----
[ 124.314940] lock(minor_rwsem#2);
[ 124.314951] lock(dvbdev_register_lock);
[ 124.314964] lock(minor_rwsem#2);
[ 124.314977] lock(&fe->lock);
[ 124.314987]
[ 124.314987] *** DEADLOCK ***
[ 124.314989]
[ 124.315007] 2 locks held by kaffeine/3743:
[ 124.315016] #0: (dvbdev_mutex){+.+...}, at: [<f8e430be>] dvb_device_open+0x1a/0x185 [dvb_core]
[ 124.315040] #1: (minor_rwsem#2){++++..}, at: [<f8e430c8>] dvb_device_open+0x24/0x185 [dvb_core]
[ 124.315065]
[ 124.315066] stack backtrace:
[ 124.315080] Pid: 3743, comm: kaffeine Not tainted 3.3.0-rc2-main+ #22
[ 124.315091] Call Trace:
[ 124.315103] [<c011dd19>] ? console_unlock+0x1ad/0x1d3
[ 124.315116] [<c043cfa8>] print_circular_bug+0x215/0x222
[ 124.315129] [<c0148d54>] __lock_acquire+0xd88/0x12b8
[ 124.315141] [<c0103d67>] ? print_context_stack+0x7a/0x8d
[ 124.315153] [<c0103268>] ? dump_trace+0x78/0xa5
[ 124.315165] [<c0149609>] lock_acquire+0x45/0x5c
[ 124.315178] [<f85e70cf>] ? videobuf_dvb_find_frontend+0x16/0x3e [videobuf_dvb]
[ 124.315194] [<f85e70cf>] ? videobuf_dvb_find_frontend+0x16/0x3e [videobuf_dvb]
[ 124.315208] [<c0440b37>] mutex_lock_nested+0x35/0x275
[ 124.315222] [<f85e70cf>] ? videobuf_dvb_find_frontend+0x16/0x3e [videobuf_dvb]
[ 124.315237] [<f85e70cf>] videobuf_dvb_find_frontend+0x16/0x3e [videobuf_dvb]
[ 124.315254] [<f86ced7a>] cx88_dvb_bus_ctrl+0x22/0x9a [cx88_dvb]
[ 124.315273] [<f8e4982f>] dvb_frontend_open+0x14b/0x2ee [dvb_core]
[ 124.315293] [<f8e43173>] dvb_device_open+0xcf/0x185 [dvb_core]
[ 124.315307] [<c0194f15>] chrdev_open+0x14e/0x16c
[ 124.315320] [<c019056b>] __dentry_open+0x193/0x288
[ 124.315333] [<c044502f>] ? sub_preempt_count+0x81/0x8e
[ 124.315345] [<c01913a9>] nameidata_to_filp+0x42/0x50
[ 124.315357] [<c0194dc7>] ? cdev_put+0x1a/0x1a
[ 124.315369] [<c019c89b>] do_last+0x6db/0x6ed
[ 124.315381] [<c019c973>] path_openat+0xa1/0x2c2
[ 124.315393] [<c019cc40>] do_filp_open+0x21/0x5d
[ 124.315406] [<c044502f>] ? sub_preempt_count+0x81/0x8e
[ 124.315418] [<c04428ba>] ? _raw_spin_unlock+0x27/0x3d
[ 124.315432] [<c01a5a8f>] ? alloc_fd+0xb3/0xbe
[ 124.315444] [<c01914a5>] do_sys_open+0xee/0x167
[ 124.315456] [<c019153d>] sys_open+0x1f/0x27
[ 124.315468] [<c0442bf5>] syscall_call+0x7/0xb
[ 124.315480] [<c0440000>] ? schedule_timeout_interruptible+0x8/0x16
Software
=======
openSuSE 12.1, Tumbleweed
X.Org X Server 1.11.99.902 (1.12.0 RC 2), current git master
Kaffeine: 1.2.2 (Qt: 4.7.4, KDE: 4.7.2 (4.7.2) "release 5")
Hardware
========
AOpen i915GMm-hfs, Pentium-M Dothan (2GHz), 2GB RAM**
Hauppauge WinTV Nova-HD-S2
cu,
knut
prev parent reply other threads:[~2012-02-06 7:15 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-05 20:57 [BUG 3.3-rc2] spinlock trylock failure on UP on CPU#0 Knut Petersen
2012-02-05 22:55 ` Linus Torvalds
2012-02-06 1:25 ` Shaohua Li
[not found] ` <4F2F7D04.6020502@t-online.de>
2012-02-06 7:13 ` Shaohua Li
2012-02-06 7:15 ` Knut Petersen [this message]
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