Comment 15 for bug 1483343

------- Comment From <email address hidden> 2016-01-05 17:08 EDT-------
Re-posting most recent comment so Canonical can see it:

Similar behaviour is observed in ubuntu 14.04.4 testing.

runltp test execution stopped after executing rcu_torture test

Fllowing Call trace is observed in "dmesg" output

[63437.060777] INFO: rcu_sched self-detected stall on CPU { 6} (t=11284398 jiffies g=511721 c=511720 q=147264)
[63437.060796] Task dump for CPU 6:
[63437.060798] lock_torture_wr R running task 0 32581 2 0x00000804
[63437.060803] Call Trace:
[63437.060806] [c000000306ec7560] [c0000000000f55f0] sched_show_task+0xe0/0x180 (unreliable)
[63437.060812] [c000000306ec75d0] [c000000000133c58] rcu_dump_cpu_stacks+0xe8/0x160
[63437.060817] [c000000306ec7620] [c0000000001384a4] rcu_check_callbacks+0x634/0x960
[63437.060822] [c000000306ec7750] [c00000000013fec8] update_process_times+0x58/0xa0
[63437.060826] [c000000306ec7780] [c000000000156438] tick_sched_handle.isra.15+0x48/0xe0
[63437.060831] [c000000306ec77c0] [c000000000156534] tick_sched_timer+0x64/0xc0
[63437.060836] [c000000306ec7800] [c000000000140954] __hrtimer_run_queues+0x124/0x350
[63437.060841] [c000000306ec7890] [c00000000014174c] hrtimer_interrupt+0xec/0x290
[63437.060846] [c000000306ec7950] [c00000000001f3c0] __timer_interrupt+0x90/0x230
[63437.060851] [c000000306ec79a0] [c00000000001f710] timer_interrupt+0xa0/0xe0
[63437.060855] [c000000306ec79d0] [c000000000002714] decrementer_common+0x114/0x180
[63437.060861] --- interrupt: 901 at udelay+0x44/0x60
[63437.060861] LR = torture_rwlock_write_delay+0x5c/0x90 [locktorture]
[63437.060868] [c000000306ec7cc0] [d000000004010bc8] torture_rwlock_write_delay+0x28/0x90 [locktorture] (unreliable)
[63437.060874] [c000000306ec7cf0] [d0000000040105c0] lock_torture_writer+0xe0/0x210 [locktorture]
[63437.060880] [c000000306ec7d80] [c0000000000e0a74] kthread+0x114/0x140
[63437.060884] [c000000306ec7e30] [c000000000009538] ret_from_kernel_thread+0x5c/0xa4