kernel-packages team mailing list archive

[Rafael David Tinoco <rafael.tinoco@xxxxxxxxxxxxx>]

Unfortunately I received 2 other kdumps from the same user and it looks like that other 2 kdumps were
happening because of a NULL dereference (3.2.0-79). I asked them to test latest 3.2 kernel + the fix 
I commented above. 

User still faced kdumps with latest 3.2 but only with khungtask complaining about soft lockups. A first
look into the dumps showed a lock contention: 

crash> bt ffff883f70c78000 
PID: 41940 TASK: ffff883f70c78000 CPU: 13 COMMAND: "java" 
#0 [ffff883f69093d98] __schedule at ffffffff81666f4a 
#1 [ffff883f69093e20] schedule at ffffffff816675cf 
#2 [ffff883f69093e30] rwsem_down_failed_common at ffffffff8166940d 
#3 [ffff883f69093ea0] rwsem_down_write_failed at ffffffff816694c3 
#4 [ffff883f69093eb0] call_rwsem_down_write_failed at ffffffff8131fb43 
#5 [ffff883f69093f10] sys_mprotect at ffffffff811488f0 
#6 [ffff883f69093f80] system_call_fastpath at ffffffff81671c62 
RIP: 00007f1adc172cc7 RSP: 00007f1adcc89c60 RFLAGS: 00010297 
RAX: 000000000000000a RBX: ffffffff81671c62 RCX: 00000000ef038c60 
RDX: 0000000000000003 RSI: 0000000000002000 RDI: 00007f1ad49bc000 
RBP: 0000000000002010 R8: 00000000009be000 R9: 0000000000000000 
R10: 00000000009bc000 R11: 0000000000000206 R12: 0000000000000ac0 
R13: 00007f1ad49bb540 R14: 0000000000002000 R15: 00007f1ad4000078 
ORIG_RAX: 000000000000000a CS: 0033 SS: 002b 

on the task monitored by khungtask thread.

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1534413

Title:
  Precise: lockup during fadvise syscall with POSIX_FADV_DONTNEED

Status in linux package in Ubuntu:
  In Progress

Bug description:
  It was brought to my knowledge a kernel dump (3.2.0-79) with the
  following stack trace:

  """
  [14277.952072] usb 3-1: USB disconnect, device number 3
  [15388.602790] NOHZ: local_softirq_pending 02
  [15404.593795] NOHZ: local_softirq_pending 02
  [15436.575787] NOHZ: local_softirq_pending 02
  [15452.566802] NOHZ: local_softirq_pending 02
  [15456.564528] NOHZ: local_softirq_pending 02
  [15564.503842] NOHZ: local_softirq_pending 02
  [15584.492538] NOHZ: local_softirq_pending 02
  [15588.490302] NOHZ: local_softirq_pending 02
  [15632.465563] NOHZ: local_softirq_pending 02
  [15659.014629] NOHZ: local_softirq_pending 02
  [15956.371298] INFO: task jsvc:57263 blocked for more than 120 seconds.
  [15956.375347] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [15956.383487] jsvc            D ffffffff81806200     0 57263   9495 0x00000000
  [15956.383493]  ffff883e849c3d08 0000000000000082 ffff883e849c3ca8 000000008104f624
  [15956.383502]  ffff883e849c3fd8 ffff883e849c3fd8 ffff883e849c3fd8 0000000000012800
  [15956.383509]  ffff881f72db9700 ffff883e0c4e2e00 ffff883e849c3cf8 7fffffffffffffff
  [15956.383518] Call Trace:
  [15956.383534]  [<ffffffff81662c0f>] schedule+0x3f/0x60
  [15956.383539]  [<ffffffff8166324d>] schedule_timeout+0x29d/0x310
  [15956.383547]  [<ffffffff810388be>] ? physflat_send_IPI_mask+0xe/0x10
  [15956.383554]  [<ffffffff81032068>] ? native_smp_send_reschedule+0x48/0x60
  [15956.383560]  [<ffffffff8103ec29>] ? default_spin_lock_flags+0x9/0x10
  [15956.383564]  [<ffffffff81662a4f>] wait_for_common+0xdf/0x180
  [15956.383572]  [<ffffffff81060ac0>] ? try_to_wake_up+0x200/0x200
  [15956.383576]  [<ffffffff81662bcd>] wait_for_completion+0x1d/0x20
  [15956.383585]  [<ffffffff8108757e>] flush_work+0x2e/0x40
  [15956.383589]  [<ffffffff810838b0>] ? wake_up_worker+0x30/0x30
  [15956.383593]  [<ffffffff81087813>] schedule_on_each_cpu+0xc3/0x110
  [15956.383602]  [<ffffffff81127365>] lru_add_drain_all+0x15/0x20
  [15956.383607]  [<ffffffff8111e189>] sys_fadvise64_64+0x189/0x270
  [15956.383610]  [<ffffffff8111e27e>] sys_fadvise64+0xe/0x10
  [15956.383619]  [<ffffffff8166d2c2>] system_call_fastpath+0x16/0x1b
  [15956.383622] Kernel panic - not syncing: hung_task: blocked tasks
  [15956.388083] Pid: 178, comm: khungtaskd Tainted: G        W    3.2.0-79-generic #115-Ubuntu
  [15956.397273] Call Trace:
  [15956.401783]  [<ffffffff8164c005>] panic+0x91/0x1a4
  [15956.406527]  [<ffffffff810d97c2>] check_hung_task+0xb2/0xc0
  [15956.411393]  [<ffffffff810d98eb>] check_hung_uninterruptible_tasks+0x11b/0x140
  [15956.421117]  [<ffffffff810d9910>] ? check_hung_uninterruptible_tasks+0x140/0x140
  [15956.431847]  [<ffffffff810d995f>] watchdog+0x4f/0x60
  [15956.437524]  [<ffffffff8108b99c>] kthread+0x8c/0xa0
  [15956.443145]  [<ffffffff8166f434>] kernel_thread_helper+0x4/0x10
  [15956.448830]  [<ffffffff8108b910>] ? flush_kthread_worker+0xa0/0xa0
  [15956.454700]  [<ffffffff8166f430>] ? gs_change+0x13/0x13
  """

  Analysis being made on the comments...

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1534413/+subscriptions