Hi Alex

We noticed the below kernel BUG on

https://github.com/alexshi/power-scheduling.git noload

commit 6b74b2031e15ae58470fd8dde7438df35e358c62
Author:     Alex Shi <alex.shi@linaro.org>
AuthorDate: Fri Apr 4 17:49:30 2014 +0800
Commit:     Alex Shi <alex.shi@linaro.org>
CommitDate: Fri Apr 4 17:49:30 2014 +0800

     sched: let task moving destination cpu do active balance

     Now we let the task source cpu do the active balance, while the
     destination cpu maybe idle. At that time the task will be stopped
     on resource cpu and wait the destination cpu up. That hurt the
     performace. Let destination cpu do active balance will give task


<3>[  614.504149] INFO: rcu_sched self-detected stall on CPU { 3}  (t=100007 jiffies g=1455 c=1454 q=87882)
<6>[  614.504731] sending NMI to all CPUs:
<4>[  614.505003] NMI backtrace for cpu 0
<4>[  614.505228] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.0-01205-g0e2d6b2 #1
<4>[  614.505671] Hardware name:                  /DX58SO, BIOS SOX5810J.86A.4196.2009.0715.1958 07/15/2009
<4>[  614.506185] task: ffffffff82011440 ti: ffffffff82000000 task.ti: ffffffff82000000
<4>[  614.506637] RIP: 0010:[<ffffffff814c7599>]  [<ffffffff814c7599>] intel_idle+0xdc/0x132
<4>[  614.507116] RSP: 0018:ffffffff82001e48  EFLAGS: 00000046
<4>[  614.507401] RAX: 0000000000000020 RBX: 0000000000000008 RCX: 0000000000000001
<4>[  614.507750] RDX: 0000000000000000 RSI: 0000000000000046 RDI: 0000000000000046
<4>[  614.508100] RBP: ffffffff82001e70 R08: ffff8800bf213ebc R09: 00000000000000ca
<4>[  614.508449] R10: 0000000000000006 R11: 000000000000049a R12: 0000000000000004
<4>[  614.508799] R13: 0000000000000020 R14: 0000000000000003 R15: 0000000000000000
<4>[  614.509148] FS:  0000000000000000(0000) GS:ffff8800bf200000(0000) knlGS:0000000000000000
<4>[  614.509622] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
<4>[  614.509922] CR2: 00000000025ae424 CR3: 000000000200c000 CR4: 00000000000007f0
<4>[  614.510271] Stack:
<4>[  614.510440]  0000000000000018 ffff8800bf21dd00 ffffffff820a2a18 0000008f0b6dd4cf
<4>[  614.510918]  0000000008004000 ffffffff82001eb0 ffffffff81866cb1 0000000400000006
<4>[  614.511396]  ffffffff820a28a0 ffff8800bf21dd00 0000000000000004 ffffffff820a28a0
<4>[  614.511874] Call Trace:
<4>[  614.512061]  [<ffffffff81866cb1>] cpuidle_enter_state+0x45/0xb5
<4>[  614.512369]  [<ffffffff81866e2c>] cpuidle_idle_call+0x10b/0x1db
<4>[  614.512678]  [<ffffffff8104241b>] arch_cpu_idle+0xe/0x28
<4>[  614.512965]  [<ffffffff8112452b>] cpu_startup_entry+0x131/0x20a
<4>[  614.513273]  [<ffffffff819aae53>] rest_init+0x87/0x89
<4>[  614.513550]  [<ffffffff8214fde0>] start_kernel+0x407/0x412
<4>[  614.513842]  [<ffffffff8214f7e7>] ? repair_env_string+0x58/0x58
<4>[  614.514150]  [<ffffffff8214f120>] ? early_idt_handlers+0x120/0x120
<4>[  614.514466]  [<ffffffff8214f4a2>] x86_64_start_reservations+0x2a/0x2c
<4>[  614.514792]  [<ffffffff8214f5df>] x86_64_start_kernel+0x13b/0x148
<4>[  614.515104] Code: b9 00 00 48 89 d1 48 2d c8 1f 00 00 0f 01 c8 65 48 8b 04 25 60 b9 00 00 48 8b 80 38 e0 ff ff a8 08 75 08 b1 01 4c 89 e8 0f 01 c9 <65> 48 8b 04 25 60 b9 00 00 83 a0 3c e0 ff ff fb 0f ae f0 65 48
<4>[  614.519105] NMI backtrace for cpu 1

Full dmesg & Kconifg are attached, and more details can be provided on your request.

Thanks,
Jet