Comment # 5 on bug 1079747 from Dominique Leuenberger

I gave this a try on Staging:B/tar/standard/i586, and the log spit out:

[  598s] 141: storing long sparse file names                  ok
[17760s] 142: listing sparse files bigger than 2^33 B        [17744.267539]
sysrq: SysRq : This sysrq operation is disabled.


Send sysrq 9 to Job
[17796s] [17780.647309] sysrq: SysRq : Show State
[17796s] [17780.648108]   task                PC stack   pid father
[17796s] [17780.649201] build           S    0     1      0 0x00000000
[17796s] [17780.650363] Call Trace:
[17796s] [17780.650885]  ? __schedule+0x2a5/0x920
[17796s] [17780.651642]  ? schedule+0x2d/0x80
[17796s] [17780.652332]  ? do_wait+0x1af/0x220
[17796s] [17780.653038]  ? kernel_wait4+0x70/0x110
[17796s] [17780.653810]  ? task_stopped_code+0x60/0x60
[17796s] [17780.654666]  ? do_int80_syscall_32+0x51/0x100
[17796s] [17780.655560]  ? entry_INT80_32+0x36/0x36
[17796s] [17780.656351] kthreadd        S    0     2      0 0x80000000
[17796s] [17780.658023] Call Trace:
[17796s] [17780.658555]  ? __schedule+0x2a5/0x920
[17796s] [17780.659312]  ? schedule+0x2d/0x80
[17796s] [17780.660000]  ? kthreadd+0x195/0x1b0
[17796s] [17780.660720]  ? kthread_create_on_cpu+0xa0/0xa0
[17796s] [17780.661635]  ? ret_from_fork+0x2e/0x38
[17796s] [17780.662447] kworker/0:0H    I    0     4      2 0x80000000
[17796s] [17780.663578] Call Trace:
[17796s] [17780.664098]  ? __schedule+0x2a5/0x920
[17796s] [17780.664871]  ? schedule+0x2d/0x80
[17796s] [17780.665569]  ? worker_thread+0xa6/0x400
[17796s] [17780.666402]  ? kthread+0xf0/0x110
[17796s] [17780.667096]  ? process_one_work+0x3d0/0x3d0
[17796s] [17780.668750]  ? kthread_create_worker_on_cpu+0x20/0x20
[17796s] [17780.669795]  ? ret_from_fork+0x2e/0x38
[17796s] [17780.670607] mm_percpu_wq    I    0     6      2 0x80000000
[17796s] [17780.671743] Call Trace:
[17796s] [17780.672273]  ? __schedule+0x2a5/0x920
[17796s] [17780.673043]  ? schedule+0x2d/0x80
[17796s] [17780.673743]  ? rescuer_thread+0x2ce/0x310
[17796s] [17780.674608]  ? preempt_schedule_common+0x11/0x30
[17796s] [17780.675567]  ? kthread+0xf0/0x110
[17796s] [17780.676262]  ? cancel_delayed_work_sync+0x20/0x20
[17796s] [17780.677239]  ? kthread_create_worker_on_cpu+0x20/0x20
[17796s] [17780.678574]  ? ret_from_fork+0x2e/0x38
[17796s] [17780.679351] ksoftirqd/0     S    0     7      2 0x80000000
[17796s] [17780.680475] Call Trace:
[17796s] [17780.680998]  ? __schedule+0x2a5/0x920
[17796s] [17780.681754]  ? schedule+0x2d/0x80
[17796s] [17780.682459]  ? smpboot_thread_fn+0x1b4/0x200
[17796s] [17780.683348]  ? kthread+0xf0/0x110
[17796s] [17780.684044]  ? sort_range+0x20/0x20
[17796s] [17780.684779]  ? kthread_create_worker_on_cpu+0x20/0x20
[17796s] [17780.685825]  ? ret_from_fork+0x2e/0x38
[17796s] [17780.686917] rcu_preempt     I    0     8      2 0x80000000
[...]