For a better tracking of this bug, I have filed in launchpad. https://bugs.launchpad.net/linaro-stable-kernel/+bug/1317401
On 5 May 2014 23:36, Paul E. McKenney paulmck@linux.vnet.ibm.com wrote:
On Mon, May 05, 2014 at 05:39:43PM +0800, Alex Shi wrote:
I keep seeing the RCU stall problem on panda board from 3.10 kernel to
latest upstream kernel
and google find some one report it before:
https://lkml.org/lkml/2012/9/20/519
Is it the hardware issue or a real software problem?
I cannot distinguish between hardware and software from the trace below, but given that you are also seeing a soft lockup, either way you do appear to have a real problem as opposed to an RCU CPU stall warning false positive.
Thanx, Paul95.519653] INFO: rcu_sched self-detected stall on CPU^M [ 95.519866] 1: (1 GPs behind) idle=2e7/1/0 softirq=4404/4405 ^M [ 95.526489] INFO: rcu_sched detected stalls on CPUs/tasks:^M [ 95.526489] 1: (1 GPs behind) idle=2e7/1/0 softirq=4404/4405 ^M [ 95.526489] (detected by 0, t=4229 jiffies, g=800, c=799, q=440)^M [ 95.526519] Task dump for CPU 1:^M [ 95.526519] swapper/1 R running 0 0 1 0x00000000^M [ 95.559844] (t=4229 jiffies g=800 c=799 q=440)^M [ 95.564727] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.15.0-rc4 #93^M [ 95.571502] [<c00133fd>] (unwind_backtrace) from [<c001076d>]
(show_stack+0x11/0x14)^M
[ 95.579711] [<c001076d>] (show_stack) from [<c0570465>]
(dump_stack+0x75/0x88)^M
[ 95.587371] [<c0570465>] (dump_stack) from [<c0084383>]
(rcu_check_callbacks+0x353/0x79c)^M
[ 95.596038] [<c0084383>] (rcu_check_callbacks) from [<c003e99f>]
(update_process_times+0x33/0x4c)^M
[ 95.605438] [<c003e99f>] (update_process_times) from [<c008e5a3>]
(tick_sched_handle.isra.18+0x1f/0x48)^M
[ 95.615386] [<c008e5a3>] (tick_sched_handle.isra.18) from
[<c008e609>] (tick_sched_timer+0x3d/0x5c)^M
[ 95.624969] [<c008e609>] (tick_sched_timer) from [<c0051a23>]
(__run_hrtimer+0x67/0x310)^M
[ 95.633544] [<c0051a23>] (__run_hrtimer) from [<c00525fd>]
(hrtimer_interrupt+0xe1/0x214)^M
[ 95.642211] [<c00525fd>] (hrtimer_interrupt) from [<c008cecb>]
(tick_receive_broadcast+0x1f/0x30)^M
[ 95.651611] [<c008cecb>] (tick_receive_broadcast) from [<c0011e4f>]
(handle_IPI+0xb3/0x120)^M
[ 95.660461] [<c0011e4f>] (handle_IPI) from [<c00085e5>]
(gic_handle_irq+0x51/0x54)^M
[ 95.668487] [<c00085e5>] (gic_handle_irq) from [<c057603f>]
(__irq_svc+0x3f/0x64)^M
[ 95.676391] Exception stack(0xee0dbf10 to 0xee0dbf58)^M [ 95.681762] bf00: 00000001
00000001 00000000 ee0d8c40^M
[ 95.690429] bf20: 3c6bd296 00000016 3c6f8c43 00000016 eefab540
c08e0c84 00000000 c0fc7114^M
[ 95.699066] bf40: 00000010 ee0dbf58 c006ef4d c0443890 40000033
ffffffff^M
[ 95.706085] [<c057603f>] (__irq_svc) from [<c0443890>]
(cpuidle_enter_state+0xc0/0xc4)^M
[ 95.714477] [<c0443890>] (cpuidle_enter_state) from [<c0444d11>]
(cpuidle_enter_state_coupled+0xe1/0x290)^M
[ 95.724639] [<c0444d11>] (cpuidle_enter_state_coupled) from
[<c0067cd1>] (cpu_startup_entry+0x1a5/0x494)^M
[ 95.734680] [<c0067cd1>] (cpu_startup_entry) from [<80008685>]
(0x80008685)^M
[ 95.742095] BUG: soft lockup - CPU#1 stuck for 40s! [swapper/1:0]^M [ 95.748535] Modules linked in:^M [ 95.751770] irq event stamp: 128730^M [ 95.755462] hardirqs last enabled at (128727): [<c044388f>]
cpuidle_enter_state+0xbf/0xc4^M
[ 95.764221] hardirqs last disabled at (128728): [<c0576033>]
__irq_svc+0x33/0x64^M
[ 95.772064] softirqs last enabled at (128730): [<c00386cd>]
irq_enter+0x59/0x60^M
[ 95.779907] softirqs last disabled at (128729): [<c00386ba>]
irq_enter+0x46/0x60^M
[ 95.787750] ^M
my RCU and IDLE related kernel config as blow:
CONFIG_TREE_RCU=y CONFIG_RCU_STALL_COMMON=y CONFIG_RCU_FANOUT=32 CONFIG_RCU_FANOUT_LEAF=16 CONFIG_TREE_RCU_TRACE=y CONFIG_PROVE_RCU=y CONFIG_PROVE_RCU_REPEATEDLY=y CONFIG_SPARSE_RCU_POINTER=y CONFIG_RCU_CPU_STALL_TIMEOUT=21 CONFIG_RCU_CPU_STALL_INFO=y CONFIG_RCU_TRACE=y alexs@alex-panda:~$ cat /proc/config.gz | gunzip | grep IDLE CONFIG_NO_HZ_IDLE=y CONFIG_GENERIC_SMP_IDLE_THREAD=y CONFIG_GENERIC_IDLE_POLL_SETUP=y CONFIG_CPU_IDLE=y CONFIG_CPU_IDLE_GOV_LADDER=y CONFIG_CPU_IDLE_GOV_MENU=y CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED=y
-- Thanks Alex