Subject: BUG: using smp_processor_id() in preemptible

From: Ricardo Nabinger Sanchez <[email-masked]>
Date: Thu, 11 Jan 2018 10:31:00 -0200

Greetings,

I'm getting occasional video lock-ups, and while checking logs I found
these:

===
[  297.445296] BUG: using smp_processor_id() in preemptible [00000000] code: claws-mail/1635
[  297.445319] caller is jprobe_return+0x12/0x25
[  297.445332] CPU: 1 PID: 1635 Comm: claws-mail Not tainted 4.14.0 #1
[  297.445341] Hardware name: Micro-Star International Co., Ltd. GX780/GT780/MS-1761, BIOS E1761IMS V3.01 05/02/2011
[  297.445349] Call Trace:
[  297.445372]  dump_stack+0x9f/0xe1
[  297.445392]  check_preemption_disabled+0xec/0xf0
[  297.445409]  jprobe_return+0x12/0x25
[  297.445425]  tcp_v4_do_rcv+0x7f/0x1a0
[  297.445443]  __release_sock+0x6d/0x100
[  297.445462]  release_sock+0x2b/0xb0
[  297.445475]  tcp_recvmsg+0x300/0x8f0
[  297.445504]  ? __lock_acquire+0x3ee/0x1610
[  297.445517]  ? core_sys_select+0x240/0x3e0
[  297.445541]  inet_recvmsg+0x51/0x1b0
[  297.445566]  sock_read_iter+0x8c/0xd0
[  297.445598]  __vfs_read+0xd5/0x140
[  297.445632]  vfs_read+0x9e/0x150
[  297.445652]  SyS_read+0x45/0xa0
[  297.445675]  entry_SYSCALL_64_fastpath+0x23/0xc2
[  297.445687] RIP: 0033:0x7ff2536001b8
[  297.445696] RSP: 002b:00007ff247152890 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[  297.445713] RAX: ffffffffffffffda RBX: ffff9cd088ccbff0 RCX: 00007ff2536001b8
[  297.445721] RDX: 0000000000000005 RSI: 00007ff23c02bb43 RDI: 0000000000000013
[  297.445730] RBP: 00007ff23c02bb43 R08: 0000000000000000 R09: 00007ff23c00e520
[  297.445738] R10: 0000000000100000 R11: 0000000000000246 R12: 0000000000000086
[  297.445746] R13: 000000000000002f R14: 00007ff254d3c998 R15: 0000000000000001
...
[  366.965766] BUG: using smp_processor_id() in preemptible [00000000] code: Socket Thread/1435
[  366.965769] caller is jprobe_return+0x12/0x25
[  366.965773] CPU: 0 PID: 1435 Comm: Socket Thread Not tainted 4.14.0 #1
[  366.965775] Hardware name: Micro-Star International Co., Ltd. GX780/GT780/MS-1761, BIOS E1761IMS V3.01 05/02/2011
[  366.965777] Call Trace:
[  366.965780]  dump_stack+0x9f/0xe1
[  366.965786]  check_preemption_disabled+0xec/0xf0
[  366.965790]  jprobe_return+0x12/0x25
[  366.965793]  tcp_v4_do_rcv+0x7f/0x1a0
[  366.965797]  __release_sock+0x6d/0x100
[  366.965811]  release_sock+0x2b/0xb0
[  366.965813]  tcp_recvmsg+0x300/0x8f0
[  366.965826]  inet_recvmsg+0x51/0x1b0
[  366.965834]  SYSC_recvfrom+0xc6/0x130
[  366.965845]  ? entry_SYSCALL_64_fastpath+0x5/0xc2
[  366.965848]  ? trace_hardirqs_on_caller+0xcb/0x200
[  366.965851]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[  366.965858]  entry_SYSCALL_64_fastpath+0x23/0xc2
[  366.965860] RIP: 0033:0x7f475ab7e5da
[  366.965862] RSP: 002b:00007f47438fc8b0 EFLAGS: 00000246 ORIG_RAX: 000000000000002d
[  366.965864] RAX: ffffffffffffffda RBX: ffff9cd088ae7ff0 RCX: 00007f475ab7e5da
[  366.965865] RDX: 0000000000008000 RSI: 00007f4721202000 RDI: 000000000000007c
[  366.965867] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
[  366.965868] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000086
[  366.965869] R13: 00007f47212025a8 R14: 0000000000007a58 R15: 00007f474ba1e5f2
[  366.966571] BUG: using smp_processor_id() in preemptible [00000000] code: Socket Thread/1435
[  366.966574] caller is jprobe_return+0x12/0x25
[  366.966576] CPU: 0 PID: 1435 Comm: Socket Thread Not tainted 4.14.0 #1
[  366.966577] Hardware name: Micro-Star International Co., Ltd. GX780/GT780/MS-1761, BIOS E1761IMS V3.01 05/02/2011
[  366.966578] Call Trace:
[  366.966582]  dump_stack+0x9f/0xe1
[  366.966586]  check_preemption_disabled+0xec/0xf0
[  366.966592]  jprobe_return+0x12/0x25
[  366.966596]  tcp_v4_do_rcv+0x7f/0x1a0
[  366.966601]  __release_sock+0x6d/0x100
[  366.966606]  release_sock+0x2b/0xb0
[  366.966610]  tcp_recvmsg+0x300/0x8f0
[  366.966622]  inet_recvmsg+0x51/0x1b0
[  366.966630]  SYSC_recvfrom+0xc6/0x130
[  366.966643]  ? entry_SYSCALL_64_fastpath+0x5/0xc2
[  366.966647]  ? trace_hardirqs_on_caller+0xcb/0x200
[  366.966651]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[  366.966667]  entry_SYSCALL_64_fastpath+0x23/0xc2
[  366.966669] RIP: 0033:0x7f475ab7e5da
[  366.966670] RSP: 002b:00007f47438fc8b0 EFLAGS: 00000246 ORIG_RAX: 000000000000002d
[  366.966673] RAX: ffffffffffffffda RBX: ffff9cd088ae7ff0 RCX: 00007f475ab7e5da
[  366.966674] RDX: 0000000000008000 RSI: 00007f4721202000 RDI: 000000000000007c
[  366.966676] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
[  366.966677] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000086
[  366.966679] R13: 00007f47438fca70 R14: 00000000000005a8 R15: 00007f4721202000
[  366.979991] BUG: using smp_processor_id() in preemptible [00000000] code: Socket Thread/1435
[  366.979999] caller is jprobe_return+0x12/0x25
[  366.980004] CPU: 0 PID: 1435 Comm: Socket Thread Not tainted 4.14.0 #1
[  366.980007] Hardware name: Micro-Star International Co., Ltd. GX780/GT780/MS-1761, BIOS E1761IMS V3.01 05/02/2011
[  366.980012] Call Trace:
[  366.980023]  dump_stack+0x9f/0xe1
[  366.980033]  check_preemption_disabled+0xec/0xf0
[  366.980040]  jprobe_return+0x12/0x25
[  366.980046]  tcp_v4_do_rcv+0x7f/0x1a0
[  366.980054]  __release_sock+0x6d/0x100
[  366.980062]  release_sock+0x2b/0xb0
[  366.980068]  tcp_recvmsg+0x300/0x8f0
[  366.980105]  inet_recvmsg+0x51/0x1b0
[  366.980117]  SYSC_recvfrom+0xc6/0x130
[  366.980130]  ? entry_SYSCALL_64_fastpath+0x5/0xc2
[  366.980134]  ? trace_hardirqs_on_caller+0xcb/0x200
[  366.980137]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[  366.980145]  entry_SYSCALL_64_fastpath+0x23/0xc2
[  366.980147] RIP: 0033:0x7f475ab7e5da
[  366.980149] RSP: 002b:00007f47438fc8b0 EFLAGS: 00000246 ORIG_RAX: 000000000000002d
[  366.980152] RAX: ffffffffffffffda RBX: ffff9cd088ae7ff0 RCX: 00007f475ab7e5da
[  366.980154] RDX: 0000000000008000 RSI: 00007f4721202000 RDI: 000000000000007c
[  366.980157] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
[  366.980158] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000086
[  366.980161] R13: 0000000000008000 R14: 00007f47438fca70 R15: 00007f474ba1e5f2
===

There are many of those, and they keep popping up throughout normal
usage.  Sometimes, though, things go awry but without much information:

===
Jan 10 17:54:39 kernel: [ 2717.421681] note: Socket Thread[1812] exited with preempt_count 1
===

It seems that when the event above happens (preempt_count 1), a chain of
events unfolds and my video locks up.  Sometimes the mouse pointer will
continue to work; others it is a full lockup.

I understand this is not necessarily linked to the network stack, but as it
happens, the traces always have the network stack in common and the application
that exits has always been one that deals with network (Firefox and Claws
Mail so far).

This has been happening for quite a while now, at least since 4.9 (probably
before that).  I don't know how to trigger this: it could take as much as
45 days to "lock up" or as little as a few minutes in sequence.  Yesterday,
the first time it locked up took around 20 days, and then less than 10 minutes.

The best information I have are dumps from SysRq:
===
Jan 10 17:54:39 darkbook kernel: [ 2717.421681] note: Socket Thread[1812] exited with preempt_count 1
Jan 10 17:55:45 darkbook acpid: client 1084[0:100] has disconnected
Jan 10 17:55:46 darkbook /usr/sbin/gpm[970]: *** info [mice.c(1990)]: 
Jan 10 17:55:46 darkbook /usr/sbin/gpm[970]: imps2: Auto-detected intellimouse PS/2
Jan 10 17:56:12 darkbook kernel: [ 2811.376514] sysrq: SysRq : Show Locks Held
Jan 10 17:56:14 darkbook kernel: [ 2813.214132] sysrq: SysRq : Show backtrace of all active CPUs
Jan 10 17:56:14 darkbook kernel: [ 2813.215131] Sending NMI from CPU 0 to CPUs 1-7:
Jan 10 17:56:16 darkbook kernel: [ 2814.975638] sysrq: SysRq : Show Blocked State
Jan 10 17:56:16 darkbook kernel: [ 2814.975679]   task                        PC stack   pid father
Jan 10 17:56:20 darkbook kernel: [ 2819.060962] localStorage DB S    0  1884   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.061483] LoadRoots       S    0  1900   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.061970] SysProxySetting S    0  1901   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.062477] dconf worker    S    0  1902   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.063222] ProxyResolution S    0  1903   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.063727] DataStorage     S    0  1904   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.064175] URL Classifier  S    0  1905   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.064680] Classif~ Update S    0  1906   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.065182] DataStorage     S    0  1908   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.065718] DataStorage     S    0  1909   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.066151] SaveScripts     S    0  1910   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.066684] Cache I/O       S    0  1911   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.067149] mozStorage #1   S    0  1913   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.067693] mozStorage #2   S    0  1916   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.068222] QuotaManager IO S    0  1917   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.068721] mozStorage #3   S    0  1918   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.069210] mozStorage #4   S    0  1919   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.069714] mozStorage #5   S    0  1922   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.070242] DOM Worker      S    0  1923   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.070743] DOM Worker      S    0  1947   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.071272] IdentityCrypto  S    0  1967   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.071799] mozStorage #7   S    0  1976   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.072267] mozStorage #8   S    0  1978   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.072775] DNS Resolver #7 S    0  2265   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.073256] DNS Resolver #9 S    0  2860   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.073763] DNS Res~ver #10 S    0  2861   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.074266] DNS Res~ver #11 S    0  2862   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.074765] speechd init    S    0  2894   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.075268] BgFileSaver     S    0  2916   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.075779] mozStorage #9   S    0  2919   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.076270] DOMCacheThread  S    0  2939   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.076793] Web Content     S    0  1852   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.077632] Chrome_~dThread S    0  1855   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.078069] JS Watchdog     S    0  1858   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.078634] JS Helper       S    0  1859   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.079164] JS Helper       S    0  1860   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.079689] JS Helper       S    0  1861   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.080219] JS Helper       S    0  1862   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.080785] JS Helper       S    0  1863   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.081369] JS Helper       S    0  1864   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.081901] JS Helper       S    0  1865   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.082450] JS Helper       S    0  1866   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.082964] JS Helper       S    0  1867   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.083507] JS Helper       S    0  1868   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.084043] JS Helper       S    0  1869   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.084610] JS Helper       S    0  1870   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.085146] Socket Thread   S    0  1871   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.085872] Hang Monitor    S    0  1872   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.086379] Timer           S    0  1873   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.086886] ImgDecoder #1   S    0  1874   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.087411] ImgDecoder #2   S    0  1875   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.087960] ImgDecoder #3   S    0  1876   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.088527] ImgDecoder #4   S    0  1877   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.089036] ImgDecoder #5   S    0  1878   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.089578] ImgDecoder #6   S    0  1879   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.090130] ImgDecoder #7   S    0  1880   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.090673] ImageIO         S    0  1881   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.091220] ImageBr~geChild S    0  1882   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.092005] VideoChild      S    0  1883   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.092782] threaded-ml     S    0  1887   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.093679] ProcessHangMon  S    0  1888   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.094371] ProfilerChild   S    0  1889   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.094984] gmain           S    0  1890   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.095822] gdbus           S    0  1891   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.096438] StyleThread#0   S    0  1893   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.096909] StyleThread#1   S    0  1894   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.097453] StyleThread#2   S    0  1895   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.098059] StyleThread#3   S    0  1896   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.098717] StyleThread#4   S    0  1897   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.099407] StyleThread#5   S    0  1898   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.100011] HTML5 Parser    S    0  1914   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.100616] dconf worker    S    0  1979   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.101536] MediaPl~ack #13 S    0  2853   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.102052] MediaPl~ack #14 S    0  2854   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.102605] DOM Worker      S    0  2889   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.103124] DOM Worker      S    0  2893   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.103708] MediaTimer #3   S    0  2898   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.104244] MediaPl~ack #17 S    0  2900   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.104802] MediaPl~ack #18 S    0  2901   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.105328] MediaPD~oder #6 S    0  2902   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.105835] MediaPD~oder #7 S    0  2903   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.106378] MediaPD~oder #8 S    0  2904   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.106883] MediaPD~oder #9 S    0  2905   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.107405] DOM Worker      S    0  2938   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.107937] SubtleCrypto #1 S    0  2947   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.108457] StreamTrans #16 S    0  2954   1809 0x00000100
Jan 10 17:56:20 darkbook kernel: [ 2819.109021] fish            S    0  2165   1422 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.109522] ssh             S    0  2214   2165 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.110386] kworker/0:4     I    0  2327      2 0x80000000
Jan 10 17:56:20 darkbook kernel: [ 2819.110599] xfrun4          S    0  2329   1127 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.111390] gmain           S    0  2330   1127 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.112123] gdbus           S    0  2331   1127 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.112797] xmms            S    0  2337   2329 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.113584] xmms            S    0  2338   2329 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.114426] xmms            S    0  2339   2329 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.114842] xmms            S    0  2340   2329 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.115265] xmms            S    0  2345   2329 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.116489] xmms            S    0  2847   2329 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.117433] threaded-ml     S    0  2848   2329 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.118185] xmms            S    0  2849   2329 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.118992] kworker/0:6     I    0  2346      2 0x80000000
Jan 10 17:56:20 darkbook kernel: [ 2819.119203] kworker/0:14    I    0  2362      2 0x80000000
Jan 10 17:56:20 darkbook kernel: [ 2819.119424] fish            S    0  2414   1422 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.120179] kworker/u16:1   I    0  2455      2 0x80000000
Jan 10 17:56:20 darkbook kernel: [ 2819.120408] kworker/0:23    I    0  2520      2 0x80000000
Jan 10 17:56:20 darkbook kernel: [ 2819.120617] kworker/0:25    I    0  2540      2 0x80000000
Jan 10 17:56:20 darkbook kernel: [ 2819.120821] kworker/u16:0   I    0  2641      2 0x80000000
Jan 10 17:56:20 darkbook kernel: [ 2819.121027] kworker/2:1     I    0  2763      2 0x80000000
Jan 10 17:56:20 darkbook kernel: [ 2819.121231] kworker/0:0     I    0  2782      2 0x80000000
Jan 10 17:56:20 darkbook kernel: [ 2819.121451] kworker/0:1     I    0  2850      2 0x80000000
Jan 10 17:56:20 darkbook kernel: [ 2819.121657] kworker/0:2     I    0  2866      2 0x80000000
Jan 10 17:56:20 darkbook kernel: [ 2819.121861] kworker/0:3     I    0  2867      2 0x80000000
Jan 10 17:56:20 darkbook kernel: [ 2819.122066] kworker/2:0     I    0  2877      2 0x80000000
Jan 10 17:56:20 darkbook kernel: [ 2819.122273] kworker/0:5     I    0  2890      2 0x80000000
Jan 10 17:56:20 darkbook kernel: [ 2819.122495] kworker/0:7     I    0  2908      2 0x80000000
Jan 10 17:56:20 darkbook kernel: [ 2819.122705] kworker/0:8     I    0  2914      2 0x80000000
Jan 10 17:56:20 darkbook kernel: [ 2819.122910] kworker/0:9     I    0  2944      2 0x80000000
Jan 10 17:56:20 darkbook kernel: [ 2819.123115] kworker/0:10    I    0  2945      2 0x80000000
Jan 10 17:56:20 darkbook kernel: [ 2819.123335] kworker/0:13    I    0  2978      2 0x80000000
Jan 10 17:56:20 darkbook kernel: [ 2819.123543] kworker/0:15    I    0  2980      2 0x80000000
Jan 10 17:56:20 darkbook kernel: [ 2819.123749] xterm           S    0  2981   1126 0x00000000
Jan 10 17:56:20 darkbook kernel: [ 2819.124568] kworker/0:16    I    0  2984      2 0x80000000
Jan 10 17:56:20 darkbook kernel: [ 2819.124775] kworker/0:17    I    0  2987      2 0x80000000
Jan 10 17:56:21 darkbook kernel: [ 2819.173457] Showing busy workqueues and worker pools:
Jan 10 17:56:21 darkbook kernel: [ 2819.173480] workqueue events_freezable: flags=0x4
Jan 10 17:56:21 darkbook kernel: [ 2819.173502]   pwq 4: cpus=2 node=0 flags=0x0 nice=0 active=1/256
Jan 10 17:56:21 darkbook kernel: [ 2819.173540]     in-flight: 1635:mmc_rescan
Jan 10 17:56:21 darkbook kernel: [ 2819.173599] pool 4: cpus=2 node=0 flags=0x0 nice=0 hung=0s workers=3 idle: 2877 2763
Jan 10 17:56:21 darkbook kernel: [ 2820.056697] sysrq: SysRq : Show clockevent devices & pending hrtimers (no others)
Jan 10 17:56:23 darkbook kernel: [ 2821.458675] sysrq: SysRq : Show Regs
Jan 10 17:56:23 darkbook kernel: [ 2821.459453] 
Jan 10 17:56:23 darkbook kernel: [ 2821.459464] CPU#0: ctrl:       000000000000000f
Jan 10 17:56:23 darkbook kernel: [ 2821.459482] CPU#0: status:     8000000000000000
Jan 10 17:56:23 darkbook kernel: [ 2821.459500] CPU#0: overflow:   0000000000000000
Jan 10 17:56:23 darkbook kernel: [ 2821.459518] CPU#0: fixed:      0000000000000000
Jan 10 17:56:23 darkbook kernel: [ 2821.459537] CPU#0: pebs:       0000000000000000
Jan 10 17:56:23 darkbook kernel: [ 2821.459555] CPU#0: debugctl:   0000000000000000
Jan 10 17:56:23 darkbook kernel: [ 2821.459573] CPU#0: active:     0000000000000000
Jan 10 17:56:23 darkbook kernel: [ 2821.459592] CPU#0:   gen-PMC0 ctrl:  0000000000000000
Jan 10 17:56:23 darkbook kernel: [ 2821.459611] CPU#0:   gen-PMC0 count: 0000000000000000
Jan 10 17:56:23 darkbook kernel: [ 2821.459630] CPU#0:   gen-PMC0 left:  0000000000000000
Jan 10 17:56:23 darkbook kernel: [ 2821.459650] CPU#0:   gen-PMC1 ctrl:  0000000000000000
Jan 10 17:56:23 darkbook kernel: [ 2821.459670] CPU#0:   gen-PMC1 count: 0000000000000000
Jan 10 17:56:23 darkbook kernel: [ 2821.459689] CPU#0:   gen-PMC1 left:  0000000000000000
Jan 10 17:56:23 darkbook kernel: [ 2821.459709] CPU#0:   gen-PMC2 ctrl:  0000000000000000
Jan 10 17:56:23 darkbook kernel: [ 2821.459728] CPU#0:   gen-PMC2 count: 0000000000000000
Jan 10 17:56:23 darkbook kernel: [ 2821.459748] CPU#0:   gen-PMC2 left:  0000000000000000
Jan 10 17:56:23 darkbook kernel: [ 2821.459767] CPU#0:   gen-PMC3 ctrl:  0000000000000000
Jan 10 17:56:23 darkbook kernel: [ 2821.459787] CPU#0:   gen-PMC3 count: 000000000000ffff
Jan 10 17:56:23 darkbook kernel: [ 2821.459806] CPU#0:   gen-PMC3 left:  0000000000000000
Jan 10 17:56:23 darkbook kernel: [ 2821.459826] CPU#0: fixed-PMC0 count: 0000000000000000
Jan 10 17:56:23 darkbook kernel: [ 2821.459846] CPU#0: fixed-PMC1 count: 0000000000000000
Jan 10 17:56:23 darkbook kernel: [ 2821.459866] CPU#0: fixed-PMC2 count: 0000000000000000
Jan 10 17:56:24 darkbook kernel: [ 2822.972704] sysrq: SysRq : Show Memory
Jan 10 17:56:24 darkbook kernel: [ 2822.973707] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
Jan 10 17:56:28 darkbook kernel: [ 2827.075135] sysrq: SysRq : Emergency Sync
Jan 10 17:56:31 darkbook exiting on signal 15
===

The last one is me issuing a terminate-all-tasks so I can safely reboot.

This is a regular build with many tracing/tracers options plus some
debugging info.  It is available at <http://rnsanchez.wait4.org/config-4.14>,
if you need it.

Let me know if you need more info.

Cheers,

-- 
Ricardo Nabinger Sanchez           http://rnsanchez.wait4.org/
        "You never learned anything by doing it right."