BUG: scheduling while atomic: kswapd0/273/0x00000002

BUG: scheduling while atomic: kswapd0/273/0x00000002

[Aneesh Kumar K.V]

Hi,

With the latest patch queue i am getting the below error

-aneesh


BUG: scheduling while atomic: kswapd0/273/0x00000002
1 lock held by kswapd0/273:
 #0:  (&ei->client_lock){----}, at: [<c04a014f>] blkdev_releasepage+0x27/0x5a
Modules linked in: autofs4 hidp rfkill input_polldev sbs sbshc battery ac parport_pc lp parport i6300esb i2c_i801 i2c_core tg3 libphy e752x_edac edac_core qla2xxx scsi_transport_fc dm_multipath dm_mirror dm_region_hash dm_log dm_mod loop xt_tcpudp ip6t_REJECT ipv6 ipt_REJECT x_tables sunrpc rfcomm bnep l2cap bluetooth bridge stp sg rtc_cmos rtc_core rtc_lib pcspkr button ata_piix libata mptspi mptscsih mptbase scsi_transport_spi sd_mod scsi_mod ext3 jbd uhci_hcd ohci_hcd ehci_hcd [last unloaded: ip_tables]
Pid: 273, comm: kswapd0 Not tainted 2.6.28-rc6-autotest #1
Call Trace:
 [<c0426277>] __schedule_bug+0x5e/0x65
 [<c067d302>] schedule+0x85/0x7db
 [<c04454d6>] ? mark_held_locks+0x49/0x64
 [<c0445650>] ? trace_hardirqs_on_caller+0xe0/0x101
 [<c044567c>] ? trace_hardirqs_on+0xb/0xd
 [<c067fdc8>] ? _spin_unlock_irqrestore+0x42/0x58
 [<c043b548>] ? prepare_to_wait+0x3f/0x45
 [<c04e65dc>] jbd2_log_wait_commit+0x8e/0xd8
 [<c043b405>] ? autoremove_wake_function+0x0/0x33
 [<c04e2ca1>] jbd2_journal_try_to_free_buffers+0x175/0x185
 [<c04c71d2>] ext4_release_metadata+0x54/0x66
 [<c04c717e>] ? ext4_release_metadata+0x0/0x66
 [<c04a0166>] blkdev_releasepage+0x3e/0x5a
 [<c045e987>] try_to_release_page+0x32/0x3f
 [<c0467c5c>] shrink_page_list+0x436/0x57e
 [<c044349b>] ? put_lock_stats+0xd/0x21
 [<c044353c>] ? lock_release_holdtime+0x8d/0x93
 [<c067fe00>] ? _spin_unlock_irq+0x22/0x42
 [<c0445650>] ? trace_hardirqs_on_caller+0xe0/0x101
 [<c0467f8e>] shrink_list+0x1ea/0x47c
 [<c044349b>] ? put_lock_stats+0xd/0x21
 [<c0468432>] shrink_zone+0x212/0x27f
 [<c0468f5b>] kswapd+0x341/0x4c6
 [<c0466cc5>] ? isolate_pages_global+0x0/0x18c
 [<c043b405>] ? autoremove_wake_function+0x0/0x33
 [<c0468c1a>] ? kswapd+0x0/0x4c6
 [<c043b344>] kthread+0x3b/0x63
 [<c043b309>] ? kthread+0x0/0x63
 [<c04048f3>] kernel_thread_helper+0x7/0x10
BUG: scheduling while atomic: kswapd0/273/0x0000000

Re: BUG: scheduling while atomic: kswapd0/273/0x00000002

[Balbir Singh]

* Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [2008-12-01 20:56:56]:

> Hi,
> 
> With the latest patch queue i am getting the below error
>

Did you enable jbd_debug enabled by any chance? 

-- 
	Balbir

Re: BUG: scheduling while atomic: kswapd0/273/0x00000002

[Aneesh Kumar K.V]

On Mon, Dec 01, 2008 at 09:23:41PM +0530, Balbir Singh wrote:
> * Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [2008-12-01 20:56:56]:
> 
> > Hi,
> > 
> > With the latest patch queue i am getting the below error
> >
> 
> Did you enable jbd_debug enabled by any chance? 
> 

No. The problem is we cannot call jbd2_log_wait_commit
from blkdev_releasepage because jbd2_log_wait_commit
does a wait_event 

549                 spin_unlock(&journal->j_state_lock);
550                 wait_event(journal->j_wait_done_commit,
551                                 !tid_gt(tid, journal->j_commit_sequence));
552                 spin_lock(&journal->j_state_lock);

-aneesh

Re: BUG: scheduling while atomic: kswapd0/273/0x00000002

[Balbir Singh]

* Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [2008-12-01 21:27:55]:

> On Mon, Dec 01, 2008 at 09:23:41PM +0530, Balbir Singh wrote:
> > * Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [2008-12-01 20:56:56]:
> > 
> > > Hi,
> > > 
> > > With the latest patch queue i am getting the below error
> > >
> > 
> > Did you enable jbd_debug enabled by any chance? 
> > 
> 
> No. The problem is we cannot call jbd2_log_wait_commit
> from blkdev_releasepage because jbd2_log_wait_commit
> does a wait_event 
> 
> 549                 spin_unlock(&journal->j_state_lock);
> 550                 wait_event(journal->j_wait_done_commit,
> 551                                 !tid_gt(tid, journal->j_commit_sequence));
> 552                 spin_lock(&journal->j_state_lock);
>

Yes, I should have seen the stack. The same problem seems to exist for
ext3 as well (with log_wait_commit). kswapd() passes GFP_KERNEL as
gfp_mask in scan_control and that confuses the journalling layer,
since we hold the lock on page in shrink_page_list().

-- 
	Balbir

Re: BUG: scheduling while atomic: kswapd0/273/0x00000002

[Toshiyuki Okajima]

Aneesh Kumar K.V wrote:
> On Mon, Dec 01, 2008 at 09:23:41PM +0530, Balbir Singh wrote:
>> * Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [2008-12-01 20:56:56]:
>>
>>> Hi,
>>>
>>> With the latest patch queue i am getting the below error
>>>
>> Did you enable jbd_debug enabled by any chance? 
>>
> 
> No. The problem is we cannot call jbd2_log_wait_commit
> from blkdev_releasepage because jbd2_log_wait_commit
> does a wait_event 
> 
> 549                 spin_unlock(&journal->j_state_lock);
> 550                 wait_event(journal->j_wait_done_commit,
> 551                                 !tid_gt(tid, journal->j_commit_sequence));
> 552                 spin_lock(&journal->j_state_lock);
> 
> -aneesh
OK. This problem was caused by the patch which I made.
I will make a patch which fixes it immediately.
Thank you for your report.

Best Regards,
Toshiyuki Okajima