clocksource mutex deadlock, cat current_clocksource (2.6.33-rc6)

From: Andreas Mohr
Date: Sat Feb 06 2010 - 09:21:47 EST


Hello all,

I did

# cat /sys/devices/system/clocksource/clocksource0/current_clocksource




[oh yes indeed, that's the full output]


This is on Dell Inspiron 8000 P3/700 UP (after some suspend/resume cycles).

Haven't checked yet whether this occurs on fresh boot, too.

clocksource / event device setup is (from memory) PIT (TSC disabled due
to C2 stall) and acpi_pm (lapic is _enabled_, and CPU support only,
not BIOS).

Thanks,

Andreas Mohr

echo t > /proc/sysrq-trigger shows (full output on request):

cat D 00000000 0 19361 2959 0x00000000
de215ef8 00000046 00000000 00000000 c13b0294 dd45c380 dd45c5fc df9c6ef0
de215f28 de215f08 c13b0260 00000202 de215f28 c124fcae dd45c380 c13b0280
c13b0280 c13b0280 dd45c380 de215f08 ffffffff d9de1000 c13b0338 df9c6ef0
Call Trace:
[<c124fcae>] mutex_lock_nested+0x157/0x23d
[<c104873e>] sysfs_show_current_clocksources+0x17/0x41
[<c1048727>] ? sysfs_show_current_clocksources+0x0/0x41
[<c1196a75>] sysdev_show+0x1d/0x21
[<c10dea91>] sysfs_read_file+0x9b/0x135
[<c10de9f6>] ? sysfs_read_file+0x0/0x135
[<c109fc1b>] vfs_read+0x8c/0x13d
[<c109fd6f>] sys_read+0x40/0x65
[<c1002890>] sysenter_do_call+0x12/0x36
Sched Debug Version: v0.09, 2.6.33-rc6 #3
now at 43142470.181620 msecs
.jiffies : 4283441
.sysctl_sched_latency : 5.000000
.sysctl_sched_min_granularity : 1.000000
.sysctl_sched_wakeup_granularity : 1.000000
.sysctl_sched_child_runs_first : 0.000000
.sysctl_sched_features : 7917179
.sysctl_sched_tunable_scaling : 1 (logaritmic)

cpu#0, 698.566 MHz
.nr_running : 2
.load : 2048
.nr_switches : 17910608
.nr_load_updates : 4313441
.nr_uninterruptible : 1
.next_balance : 0.000000
.curr->pid : 9119
.clock : 43142407.895281
.cpu_load[0] : 1024
.cpu_load[1] : 1033
.cpu_load[2] : 706
.cpu_load[3] : 465
.cpu_load[4] : 406
.yld_count : 8871
.sched_switch : 0
.sched_count : 18023143
.sched_goidle : 4265782
.ttwu_count : 0
.ttwu_local : 0
.bkl_count : 0

cfs_rq[0]:
.exec_clock : 11345719.395963
.MIN_vruntime : 232465648.024326
.min_vruntime : 232465649.026399
.max_vruntime : 232465648.024326
.spread : 0.000000
.spread0 : 0.000000
.nr_running : 2
.load : 2048
.nr_spread_over : 492453

rt_rq[0]:
.rt_nr_running : 0
.rt_throttled : 0
.rt_time : 0.000000
.rt_runtime : 950.000000

runnable tasks:
task PID tree-key switches prio exec-runtime
sum-exec sum-sleep
----------------------------------------------------------------------------------------------------------
x-www-browser 3345 232465648.024326 1053319 120 232465648.024326
2047447.788077 39329053.727630
R bash 9119 232465646.526399 514 120 232465646.526399
250.811110 33621456.410620

INFO: lockdep is turned off.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/