Nicholas, I've found that the kernels I used were not able to be inspected using crash and I could not build the debug info for them. So I built a new 4.9 kernel and verified that I could inspect the crash. It is located at [1]. [1] http://mirrors.betterservers.com/trace/crash2.tar.xz ---------------- Robert LeBlanc PGP Fingerprint 79A2 9CA4 6CC4 45DD A904 C70E E654 3BB2 FA62 B9F1 On Mon, Dec 12, 2016 at 4:57 PM, Robert LeBlanc <robert@xxxxxxxxxxxxx> wrote: > Nicholas, > > After lots of set backs and having to give up trying to get kernel > dumps on our "production" systems, I've been able to work out the > issues we had with kdump and replicate the issue on my dev boxes. I > have dumps from 4.4.30 and 4.9-rc8 (makedumpfile would not dump, so it > is a straight copy of /proc/vmcore from the crash kernel). In each > crash directory, I put a details.txt file that has the process IDs > that were having problems and a brief description of the set-up at the > time. This was mostly replicated by starting fio and pulling the > Infiniband cable until fio gave up. This hardware also has Mellanox > ConnectX4-LX cards and I also replicated the issue over RoCE using 4.9 > since it has the drivers in-box. Please let me know if you need more > info, I can test much faster now. The cores/kernels/modules are > located at [1]. > > [1] http://mirrors.betterservers.com/trace/crash.tar.xz > > Thanks, > Robert > ---------------- > Robert LeBlanc > PGP Fingerprint 79A2 9CA4 6CC4 45DD A904 C70E E654 3BB2 FA62 B9F1 > > > On Fri, Nov 4, 2016 at 3:57 PM, Robert LeBlanc <robert@xxxxxxxxxxxxx> wrote: >> We hit this yesterday, this time it was on the tx thread (the other >> ones before seem to be on the rx thread). We weren't able to get a >> kernel dump on this. We'll try to get one next time. >> >> # ps axuw | grep "D.*iscs[i]" >> root 12383 0.0 0.0 0 0 ? D Nov03 0:04 [iscsi_np] >> root 23016 0.0 0.0 0 0 ? D Nov03 0:00 [iscsi_ttx] >> root 23018 0.0 0.0 0 0 ? D Nov03 0:00 [iscsi_ttx] >> # cat /proc/12383/stack >> [<ffffffff814f24af>] iscsit_stop_session+0x19f/0x1d0 >> [<ffffffff814e3c66>] iscsi_check_for_session_reinstatement+0x1e6/0x270 >> [<ffffffff814e6620>] iscsi_target_check_for_existing_instances+0x30/0x40 >> [<ffffffff814e6770>] iscsi_target_do_login+0x140/0x640 >> [<ffffffff814e7b0c>] iscsi_target_start_negotiation+0x1c/0xb0 >> [<ffffffff814e585b>] iscsi_target_login_thread+0xa9b/0xfc0 >> [<ffffffff8109d7c8>] kthread+0xd8/0xf0 >> [<ffffffff81721a8f>] ret_from_fork+0x3f/0x70 >> [<ffffffffffffffff>] 0xffffffffffffffff >> # cat /proc/23016/stack >> [<ffffffff814ce0d9>] target_wait_for_sess_cmds+0x49/0x1a0 >> [<ffffffffa058b92b>] isert_wait_conn+0x1ab/0x2f0 [ib_isert] >> [<ffffffff814f2642>] iscsit_close_connection+0x162/0x870 >> [<ffffffff814e110f>] iscsit_take_action_for_connection_exit+0x7f/0x100 >> [<ffffffff814f122a>] iscsi_target_tx_thread+0x1aa/0x1d0 >> [<ffffffff8109d7c8>] kthread+0xd8/0xf0 >> [<ffffffff81721a8f>] ret_from_fork+0x3f/0x70 >> [<ffffffffffffffff>] 0xffffffffffffffff >> # cat /proc/23018/stack >> [<ffffffff814ce0d9>] target_wait_for_sess_cmds+0x49/0x1a0 >> [<ffffffffa058b92b>] isert_wait_conn+0x1ab/0x2f0 [ib_isert] >> [<ffffffff814f2642>] iscsit_close_connection+0x162/0x870 >> [<ffffffff814e110f>] iscsit_take_action_for_connection_exit+0x7f/0x100 >> [<ffffffff814f122a>] iscsi_target_tx_thread+0x1aa/0x1d0 >> [<ffffffff8109d7c8>] kthread+0xd8/0xf0 >> [<ffffffff81721a8f>] ret_from_fork+0x3f/0x70 >> [<ffffffffffffffff>] 0xffffffffffffffff >> >> From dmesg: >> [ 394.476332] INFO: rcu_sched self-detected stall on CPU >> [ 394.476334] 20-...: (23976 ticks this GP) >> idle=edd/140000000000001/0 softirq=292/292 fqs=18788 >> [ 394.476336] (t=24003 jiffies g=3146 c=3145 q=0) >> [ 394.476337] Task dump for CPU 20: >> [ 394.476338] kworker/u68:2 R running task 0 12906 2 0x00000008 >> [ 394.476345] Workqueue: isert_comp_wq isert_cq_work [ib_isert] >> [ 394.476346] ffff883f2fe38000 00000000f805705e ffff883f7fd03da8 >> ffffffff810ac8ff >> [ 394.476347] 0000000000000014 ffffffff81adb680 ffff883f7fd03dc0 >> ffffffff810af239 >> [ 394.476348] 0000000000000015 ffff883f7fd03df0 ffffffff810e1cd0 >> ffff883f7fd17b80 >> [ 394.476348] Call Trace: >> [ 394.476354] <IRQ> [<ffffffff810ac8ff>] sched_show_task+0xaf/0x110 >> [ 394.476355] [<ffffffff810af239>] dump_cpu_task+0x39/0x40 >> [ 394.476357] [<ffffffff810e1cd0>] rcu_dump_cpu_stacks+0x80/0xb0 >> [ 394.476359] [<ffffffff810e6100>] rcu_check_callbacks+0x540/0x820 >> [ 394.476360] [<ffffffff810afe11>] ? account_system_time+0x81/0x110 >> [ 394.476363] [<ffffffff810faa60>] ? tick_sched_do_timer+0x50/0x50 >> [ 394.476364] [<ffffffff810eb599>] update_process_times+0x39/0x60 >> [ 394.476365] [<ffffffff810fa815>] tick_sched_handle.isra.17+0x25/0x60 >> [ 394.476366] [<ffffffff810faa9d>] tick_sched_timer+0x3d/0x70 >> [ 394.476368] [<ffffffff810ec182>] __hrtimer_run_queues+0x102/0x290 >> [ 394.476369] [<ffffffff810ec668>] hrtimer_interrupt+0xa8/0x1a0 >> [ 394.476372] [<ffffffff81052c65>] local_apic_timer_interrupt+0x35/0x60 >> [ 394.476374] [<ffffffff8172423d>] smp_apic_timer_interrupt+0x3d/0x50 >> [ 394.476376] [<ffffffff817224f7>] apic_timer_interrupt+0x87/0x90 >> [ 394.476379] <EOI> [<ffffffff810d71be>] ? console_unlock+0x41e/0x4e0 >> [ 394.476380] [<ffffffff810d757c>] vprintk_emit+0x2fc/0x500 >> [ 394.476382] [<ffffffff810d78ff>] vprintk_default+0x1f/0x30 >> [ 394.476384] [<ffffffff81174dde>] printk+0x5d/0x74 >> [ 394.476388] [<ffffffff814bce21>] transport_lookup_cmd_lun+0x1d1/0x200 >> [ 394.476390] [<ffffffff814ee8c0>] iscsit_setup_scsi_cmd+0x230/0x540 >> [ 394.476392] [<ffffffffa058dbf3>] isert_rx_do_work+0x3f3/0x7f0 [ib_isert] >> [ 394.476394] [<ffffffffa058e174>] isert_cq_work+0x184/0x770 [ib_isert] >> [ 394.476396] [<ffffffff8109740f>] process_one_work+0x14f/0x400 >> [ 394.476397] [<ffffffff81097c84>] worker_thread+0x114/0x470 >> [ 394.476398] [<ffffffff8171d32a>] ? __schedule+0x34a/0x7f0 >> [ 394.476399] [<ffffffff81097b70>] ? rescuer_thread+0x310/0x310 >> [ 394.476400] [<ffffffff8109d7c8>] kthread+0xd8/0xf0 >> [ 394.476402] [<ffffffff8109d6f0>] ? kthread_park+0x60/0x60 >> [ 394.476403] [<ffffffff81721a8f>] ret_from_fork+0x3f/0x70 >> [ 394.476404] [<ffffffff8109d6f0>] ? kthread_park+0x60/0x60 >> [ 405.716632] Unexpected ret: -104 send data 360 >> [ 405.721711] tx_data returned -32, expecting 360. >> ---------------- >> Robert LeBlanc >> PGP Fingerprint 79A2 9CA4 6CC4 45DD A904 C70E E654 3BB2 FA62 B9F1 >> >> >> On Mon, Oct 31, 2016 at 10:34 AM, Robert LeBlanc <robert@xxxxxxxxxxxxx> wrote: >>> Nicholas, >>> >>> Thanks for following up on this. We have been chasing other bugs in >>> our provisioning and as such has reduced our load on the boxes. We are >>> hoping to get that all straightened out this week and do some more >>> testing. So far we have not had any iSCSI in D state since the patch, >>> be we haven't been able to test it well either. We will keep you >>> updated. >>> >>> Thank you, >>> Robert LeBlanc >>> ---------------- >>> Robert LeBlanc >>> PGP Fingerprint 79A2 9CA4 6CC4 45DD A904 C70E E654 3BB2 FA62 B9F1 >>> >>> >>> On Sat, Oct 29, 2016 at 4:29 PM, Nicholas A. Bellinger >>> <nab@xxxxxxxxxxxxxxx> wrote: >>>> Hi Robert, >>>> >>>> On Wed, 2016-10-19 at 10:41 -0600, Robert LeBlanc wrote: >>>>> Nicholas, >>>>> >>>>> I didn't have high hopes for the patch because we were not seeing >>>>> TMR_ABORT_TASK (or 'abort') in dmesg or /var/log/messages, but it >>>>> seemed to help regardless. Our clients finally OOMed from the hung >>>>> sessions, so we are having to reboot them and we will do some more >>>>> testing. We haven't put the updated kernel on our clients yet. Our >>>>> clients have iSCSI root disks so I'm not sure if we can get a vmcore >>>>> on those, but we will do what we can to get you a vmcore from the >>>>> target if it happens again. >>>>> >>>> >>>> Just checking in to see if you've observed further issues with >>>> iser-target ports, and/or able to generate a crashdump with v4.4.y..? >>>> >>>>> As far as our configuration: It is a superMicro box with 6 SAMSUNG >>>>> MZ7LM3T8HCJM-00005 SSDs. Two are for root and four are in mdadm >>>>> RAID-10 for exporting via iSCSI/iSER. We have ZFS on top of the >>>>> RAID-10 for checksum and snapshots only and we export ZVols to the >>>>> clients (one or more per VM on the client). We do not persist the >>>>> export info (targetcli saveconfig), but regenerate it from scripts. >>>>> The client receives two or more of these exports and puts them in a >>>>> RAID-1 device. The exports are served by iSER one one port and also by >>>>> normal iSCSI on a different port for compatibility, but not normally >>>>> used. If you need more info about the config, please let me know. It >>>>> was kind of a vague request so I'm not sure what exactly is important >>>>> to you. >>>> >>>> Thanks for the extra details of your hardware + user-space >>>> configuration. >>>> >>>>> Thanks for helping us with this, >>>>> Robert LeBlanc >>>>> >>>>> When we have problems, we usually see this in the logs: >>>>> Oct 17 08:57:50 prv-0-12-sanstack kernel: iSCSI Login timeout on >>>>> Network Portal 0.0.0.0:3260 >>>>> Oct 17 08:57:50 prv-0-12-sanstack kernel: Unexpected ret: -104 send data 48 >>>>> Oct 17 08:57:50 prv-0-12-sanstack kernel: tx_data returned -32, expecting 48. >>>>> Oct 17 08:57:50 prv-0-12-sanstack kernel: iSCSI Login negotiation failed. >>>>> >>>>> I found some backtraces in the logs, not sure if this is helpful, this >>>>> is before your patch (your patch booted at Oct 18 10:36:59): >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: INFO: rcu_sched >>>>> self-detected stall on CPU >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: #0115-...: (41725 ticks this >>>>> GP) idle=b59/140000000000001/0 softirq=535/535 fqs=30992 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: #011 (t=42006 jiffies g=1550 >>>>> c=1549 q=0) >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: Task dump for CPU 5: >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: kworker/u68:2 R running >>>>> task 0 17967 2 0x00000008 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: Workqueue: isert_comp_wq >>>>> isert_cq_work [ib_isert] >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: ffff883f4c0dca80 >>>>> 00000000af8ca7a4 ffff883f7fb43da8 ffffffff810ac83f >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: 0000000000000005 >>>>> ffffffff81adb680 ffff883f7fb43dc0 ffffffff810af179 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: 0000000000000006 >>>>> ffff883f7fb43df0 ffffffff810e1c10 ffff883f7fb57b80 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: Call Trace: >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: <IRQ> [<ffffffff810ac83f>] >>>>> sched_show_task+0xaf/0x110 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff810af179>] >>>>> dump_cpu_task+0x39/0x40 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff810e1c10>] >>>>> rcu_dump_cpu_stacks+0x80/0xb0 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff810e6040>] >>>>> rcu_check_callbacks+0x540/0x820 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff810afd51>] ? >>>>> account_system_time+0x81/0x110 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff810fa9a0>] ? >>>>> tick_sched_do_timer+0x50/0x50 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff810eb4d9>] >>>>> update_process_times+0x39/0x60 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff810fa755>] >>>>> tick_sched_handle.isra.17+0x25/0x60 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff810fa9dd>] >>>>> tick_sched_timer+0x3d/0x70 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff810ec0c2>] >>>>> __hrtimer_run_queues+0x102/0x290 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff810ec5a8>] >>>>> hrtimer_interrupt+0xa8/0x1a0 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff81052c65>] >>>>> local_apic_timer_interrupt+0x35/0x60 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff8172343d>] >>>>> smp_apic_timer_interrupt+0x3d/0x50 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff817216f7>] >>>>> apic_timer_interrupt+0x87/0x90 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: <EOI> [<ffffffff810d70fe>] >>>>> ? console_unlock+0x41e/0x4e0 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff810d74bc>] >>>>> vprintk_emit+0x2fc/0x500 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff810d783f>] >>>>> vprintk_default+0x1f/0x30 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff81174c2a>] printk+0x5d/0x74 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff814bc351>] >>>>> transport_lookup_cmd_lun+0x1d1/0x200 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff814edcf0>] >>>>> iscsit_setup_scsi_cmd+0x230/0x540 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffffa0890bf3>] >>>>> isert_rx_do_work+0x3f3/0x7f0 [ib_isert] >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffffa0891174>] >>>>> isert_cq_work+0x184/0x770 [ib_isert] >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff8109734f>] >>>>> process_one_work+0x14f/0x400 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff81097bc4>] >>>>> worker_thread+0x114/0x470 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff8171c55a>] ? >>>>> __schedule+0x34a/0x7f0 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff81097ab0>] ? >>>>> rescuer_thread+0x310/0x310 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff8109d708>] kthread+0xd8/0xf0 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff8109d630>] ? >>>>> kthread_park+0x60/0x60 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff81720c8f>] >>>>> ret_from_fork+0x3f/0x70 >>>>> Oct 17 15:43:12 prv-0-12-sanstack kernel: [<ffffffff8109d630>] ? >>>>> kthread_park+0x60/0x60 >>>>> >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: INFO: rcu_sched >>>>> self-detected stall on CPU >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: #01128-...: (5999 ticks this >>>>> GP) idle=2f9/140000000000001/0 softirq=457/457 fqs=4830 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: #011 (t=6000 jiffies g=3546 >>>>> c=3545 q=0) >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: Task dump for CPU 28: >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: iscsi_np R running >>>>> task 0 16597 2 0x0000000c >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: ffff887f40350000 >>>>> 00000000b98a67bb ffff887f7f503da8 ffffffff810ac8ff >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: 000000000000001c >>>>> ffffffff81adb680 ffff887f7f503dc0 ffffffff810af239 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: 000000000000001d >>>>> ffff887f7f503df0 ffffffff810e1cd0 ffff887f7f517b80 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: Call Trace: >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: <IRQ> [<ffffffff810ac8ff>] >>>>> sched_show_task+0xaf/0x110 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: [<ffffffff810af239>] >>>>> dump_cpu_task+0x39/0x40 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: [<ffffffff810e1cd0>] >>>>> rcu_dump_cpu_stacks+0x80/0xb0 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: [<ffffffff810e6100>] >>>>> rcu_check_callbacks+0x540/0x820 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: [<ffffffff810afe11>] ? >>>>> account_system_time+0x81/0x110 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: [<ffffffff810faa60>] ? >>>>> tick_sched_do_timer+0x50/0x50 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: [<ffffffff810eb599>] >>>>> update_process_times+0x39/0x60 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: [<ffffffff810fa815>] >>>>> tick_sched_handle.isra.17+0x25/0x60 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: [<ffffffff810faa9d>] >>>>> tick_sched_timer+0x3d/0x70 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: [<ffffffff810ec182>] >>>>> __hrtimer_run_queues+0x102/0x290 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: [<ffffffff810ec668>] >>>>> hrtimer_interrupt+0xa8/0x1a0 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: [<ffffffff81052c65>] >>>>> local_apic_timer_interrupt+0x35/0x60 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: [<ffffffff81723cbd>] >>>>> smp_apic_timer_interrupt+0x3d/0x50 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: [<ffffffff81721f77>] >>>>> apic_timer_interrupt+0x87/0x90 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: <EOI> [<ffffffff810d71be>] >>>>> ? console_unlock+0x41e/0x4e0 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: [<ffffffff810d757c>] >>>>> vprintk_emit+0x2fc/0x500 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: [<ffffffff810d78ff>] >>>>> vprintk_default+0x1f/0x30 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: [<ffffffff81174dde>] printk+0x5d/0x74 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: [<ffffffff814e71ad>] >>>>> iscsi_target_locate_portal+0x62d/0x6f0 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: [<ffffffff814e5100>] >>>>> iscsi_target_login_thread+0x6f0/0xfc0 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: [<ffffffff814e4a10>] ? >>>>> iscsi_target_login_sess_out+0x250/0x250 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: [<ffffffff8109d7c8>] kthread+0xd8/0xf0 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: [<ffffffff8109d6f0>] ? >>>>> kthread_park+0x60/0x60 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: [<ffffffff8172150f>] >>>>> ret_from_fork+0x3f/0x70 >>>>> Oct 17 16:34:03 prv-0-12-sanstack kernel: [<ffffffff8109d6f0>] ? >>>>> kthread_park+0x60/0x60 >>>>> >>>>> I don't think this one is related, but it happened a couple of times: >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: INFO: rcu_sched >>>>> self-detected stall on CPU >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: #01119-...: (5999 ticks this >>>>> GP) idle=727/140000000000001/0 softirq=1346/1346 fqs=4990 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: #011 (t=6000 jiffies g=4295 >>>>> c=4294 q=0) >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: Task dump for CPU 19: >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: kworker/19:1 R running >>>>> task 0 301 2 0x00000008 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: Workqueue: >>>>> events_power_efficient fb_flashcursor >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: ffff883f6009ca80 >>>>> 00000000010a7cdd ffff883f7fcc3da8 ffffffff810ac8ff >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: 0000000000000013 >>>>> ffffffff81adb680 ffff883f7fcc3dc0 ffffffff810af239 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: 0000000000000014 >>>>> ffff883f7fcc3df0 ffffffff810e1cd0 ffff883f7fcd7b80 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: Call Trace: >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: <IRQ> [<ffffffff810ac8ff>] >>>>> sched_show_task+0xaf/0x110 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: [<ffffffff810af239>] >>>>> dump_cpu_task+0x39/0x40 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: [<ffffffff810e1cd0>] >>>>> rcu_dump_cpu_stacks+0x80/0xb0 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: [<ffffffff810e6100>] >>>>> rcu_check_callbacks+0x540/0x820 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: [<ffffffff810afe11>] ? >>>>> account_system_time+0x81/0x110 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: [<ffffffff810faa60>] ? >>>>> tick_sched_do_timer+0x50/0x50 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: [<ffffffff810eb599>] >>>>> update_process_times+0x39/0x60 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: [<ffffffff810fa815>] >>>>> tick_sched_handle.isra.17+0x25/0x60 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: [<ffffffff810faa9d>] >>>>> tick_sched_timer+0x3d/0x70 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: [<ffffffff810ec182>] >>>>> __hrtimer_run_queues+0x102/0x290 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: [<ffffffff810ec668>] >>>>> hrtimer_interrupt+0xa8/0x1a0 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: [<ffffffff81052c65>] >>>>> local_apic_timer_interrupt+0x35/0x60 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: [<ffffffff81723cbd>] >>>>> smp_apic_timer_interrupt+0x3d/0x50 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: [<ffffffff81721f77>] >>>>> apic_timer_interrupt+0x87/0x90 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: <EOI> [<ffffffff810d71be>] >>>>> ? console_unlock+0x41e/0x4e0 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: [<ffffffff813866ad>] >>>>> fb_flashcursor+0x5d/0x140 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: [<ffffffff8138bc00>] ? >>>>> bit_clear+0x110/0x110 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: [<ffffffff8109740f>] >>>>> process_one_work+0x14f/0x400 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: [<ffffffff81097c84>] >>>>> worker_thread+0x114/0x470 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: [<ffffffff8171cdda>] ? >>>>> __schedule+0x34a/0x7f0 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: [<ffffffff81097b70>] ? >>>>> rescuer_thread+0x310/0x310 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: [<ffffffff8109d7c8>] kthread+0xd8/0xf0 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: [<ffffffff8109d6f0>] ? >>>>> kthread_park+0x60/0x60 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: [<ffffffff8172150f>] >>>>> ret_from_fork+0x3f/0x70 >>>>> Oct 17 11:46:52 prv-0-12-sanstack kernel: [<ffffffff8109d6f0>] ? >>>>> kthread_park+0x60/0x60 >>>> >>>> RCU self-detected schedule stalls typically mean some code is >>>> monopolizing execution on a specific CPU for an extended period of time >>>> (eg: endless loop), preventing normal RCU grace-period callbacks from >>>> running in a timely manner. >>>> >>>> It's hard to tell without more log context and/or crashdump what was >>>> going on here. >>>> -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html